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Discussion Starter #1
Five Years ago I embarked on a project to integrade a fully functional windows computer into my Patrol. Why do this you may ask?
Firstly, because I can and I enjoy computer projects.
Secondly, A computer is a versatile platform that has many uses in a vehicle, including the following:
  • Connection to the engine control to display live gauges and engine alarms
  • Read and clear fault codes without the need for an external tool
  • A full infotainment system comparable to brand new cars
  • Being able to store and consume music, movies, TV shows and even service manuals, built right into the car
  • Its able to be updated on a whim to add new features; you're not at the mercy of a new vehicle manufacturer to update software for you
  • It makes retrofitting new technologies like digital radio possible, without upgrading head units
I have been running this system without major fault for 5years now and it is still going strong. I recently got Android Auto integration working once again, so I figured I'd put and edited version of my original build log up here. I'll do the entries as a series of posts. I've also tried to edit out a lot of useless dribble out to make things a lot more concise. Hopefully you will be inspired to do something similar, because as far as I know my Patrol is the only one in the world running a car PC. So without further ado here it is:
 

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Discussion Starter #2
Introduction & Design
To make a system that does everything I want, I needed to come up with a solution that is versatile, modular and upgradable. After thinking about this, I decided to build a pc that is both compact and powerful enough to run all of the functions listed above concurrently, but is also durable enough to withstand the harsh conditions of the Australian environment. This is no easy feat, but I have a plan to make it work.

The basic layout of the system will be to have the computer mounted in the highest point in the car, away from the water, dust and sand. To control it I'll be running a touch screen mounted in the dash, in place of the factory double sized radio head unit.

(Please note the computer components are way out of date and have been superseeded by newer counterparts, however the case and power supply may still be avaliable) Now to build the computer - I chose components system with power efficiency given slightly higher priority than performance. The biggest concern for me was power consumption, as in later stages I plan to leave the computer running from a separate battery when the car's engine is off, but in order to get good life from the battery it can't draw too much current. I found a local supplier here that sells computer cases and power supplies that adapt the 12V DC from the car's battery to the necessary voltages and currents that the computer needs.

I chose the following power supply & case combo as they are designed for vehicle use and have some handy features that will make integration into the car's electrical system easier later on.

PSU
Case

The PSU is capable of 140W max sustained output, which for a computer is not much at all (to give a comparison the one in my home computer is rated at 750W)

The case takes a Micro ATX form factor motherboard, which is basically a mini version of the boards found in most desktop PC's. The advantage of this is you can have a motherboard with all the onboard features of a regular desktop PC in a super compact package.

To save space and installing extra components, I wanted a motherboard that has onboard WiFi and Bluetooth. I settled on the ASUS Z97I-PLUS because its a solid motherboard that meets these requirements and has heaps of handy features for power saving, as well as a complementary software suite for monitoring and control.

For the CPU I chose an Intel i3-4360. It has a low TDP (54 watts) but still packs a punch with a 3.7ghz clock speed.

I chose 8gb of relatively cheap Kingston KVR16N11S8K2/8 memory, it's not the fastest or best quality but crucially it is very low profile which was necessary to fit it inside the slim computer case.

I chose Window 8.1 as the OS (this was current at the time of writing but has since been updated to 10), as obviously it has a huge range of applications made for it and it has the advantage of already being optimized for touchscreen use.

For fast boot times and extra shock-proofing I chose a 250GB samsung evo 840 series SSD

I also bought a Samsung USB powered DVD-RW drive for watching DVD's but I didn't end up using it. Now, to start the build:


As with any PC build, one of the first steps is to prepare the case for mounting the motherboard. The power supply is designed for the case, so it was a simple matter of screwing it onto the stand-offs on the motherboard tray.


Then I mounted the motherboard and installed the CPU:
Note the black 8 pin connector on the motherboard in the upper left corner next to the heat sink, and the 24 pin connector in the upper right corner
Next was to install all the wiring to hook it up:
The wiring is partially complete in this photo

This is where I ran into the first major challenge of the build. The power supply has the standard 20 pin ATX connector that supplies power to the motherboard, and a 4 pin connector for CPU power. This is an outdated design, as modern motherboards use a 24 pin connector for the motherboard power and an 8 pin connector for the CPU power (my motherboard has these in the photos above).

I connected the power supply to a car battery to power on the computer for testing, and lo and behold, it didn't boot. In fact, it didn't even pass POST. This had me scratching my head for a while, and I eventually worked out that the computer wasn't getting enough power to the motherboard and CPU.

I needed to create a solution. I used a schematic from the internet to figure out which pins do what, and what voltages of the 4 extra motherboard pins require, then I spliced into the wires from the PSU connector and wired them into a spare 4 pin plug to make up the extra 4 pins.

For the CPU power, the wiring is quite simple, half of the wires are +12V and the other half are for earth. I simply cut the wires going from the 4 pin CPU plug on the power supply and bifurcated them, running one wire to each 4 pin plug so that the 4 pin connector on the power supply end became two 4 pin connectors on the motherboard end.

I didn't have the 4 pin connectors I needed, so I had to make a trip to a couple of local computer stores and asked them if they had any spare 4 pin and 8 pin cables, which one of the salespeople kindly gave me for free as they were leftovers from previous builds. Alternatively, you could scavenge them from old power supplies.

With that problem solved, I moved the computer to my computer room, and borrowed my home PC to power the motherboard and other components while I installed windows onto it.
The car computer (sitting on the table to the right) next to my main PC. The main PC isn't actually running, its power supply is powering the car PC.
The last step was to so some cable management and fit the computer into its case. I should note that it was a very tight squeeze as there was no clearance between the plastic fan bracket on the CPU cooler and the top of the case. Choosing a more powerful CPU wouldn't have been possible as the coolers on them are taller and would not fit in the case.
You can see how little room there is between the CPU fan bracket and the case
This is the final assembled PC:
Perspective View: The VoomPC logo lights up blue when the computer is running


Back view: The white connector on the far right is for the power supply connections for easy removal.


Top view


Side view with the case upside down. You can see that the motherboard tray slides into the black case from one end. Its held in by screws that screw into the back of the computer. The SSD tray uses a similar system and is on a separate rail that slides in behind the front of the case.
The next step was to design a way to mount the computer in the car.
 

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Discussion Starter #3
Roof Console

In this post I'll go through how I found a way to mount it in the car.

I had a few problems that I needed to solve in order for the computer to work reliably for a long time.
  • How to minimize the impact of dust, water and heat on the computer's performance
  • How to run power and wiring for all the peripherals to the computer
  • How to make the computer easily accessible and serviceable without being intrusive
To keep the PC as far away from dust and water as possible, I chose to have a roof console custom made. A roof console is basically just a narrow box that attaches to the roof of the car and runs from the front of the car backwards down the centre. They are normally used for extra storage and mounting 2 way radios, reading lights ect. This choice is a trade-off as being the highest point in the cabin it naturally gets the hottest and will absorb heat generated by the sun shining on the roof. However the protection from water and dust, while also being in a position where it is out of the way was worth it.

After doing some research I found an Australian company that specializes in designing building roof consoles (and other interior accessories) called Department of the Interior.

Under my guidance, we designed a console to house the computer. I had to have the PC shipped to them so they could use it for measurements. The console we designed (I modified one of their off-the shelf designs) and attaches using the mounting holes from the car's factory fitted roof console. I also had them put in some switch slots as I needed the spots for switches for the computer and other electrical accessories.
Prototype design of the console


A few weeks and several hundred dollars later the console arrived and I could resume the build.








Underside view - you can see the computer mounted in the console. As an added bonus the wooden construction should help reduce vibrations from the engine being transferred into (and thus damaging) the PC's components.
Installing the unit into the car was slightly complicated; First I removed the rear view mirror and the factory plastic console that housed the sunglasses holder and two reading lights, and unscrewed the factory center cabin light.
Forward end where the console was, note the two screw holes in the metal plate





Then I removed the sunglasses holder from the factory console and installed it in the roof console. Getting the holder in the right position was slightly annoying, as a slight misalignment meant it would catch on the console and not swing open. This is most likely due to console being hand made and the expansion and contracting of the wood with temperature and humidity.






The console came with a steel bracket on the end which serves to secure the console onto the car. This had to be removed in order to install the sunglasses holder.
Console with steel bracket removed and sunglasses holder installed

In order to be able to screw the console into the holes in the roof, I had to drill two holes in the top of the sunglasses holder to access the screw heads.


The next step was to reattach the steel bracket.
Steel bracket partially attached (2 screws missing). The two nuts welded onto the bracket serve as spacers and position the console at the correct height in relation to the roof lining.
The console could now be installed. Installation was slightly tricky. In order to align the two front screws, I had to perch one between the underside of one of the the nuts in the picture above and the sunglasses holder, and the other I held up against the underside of the steel bracket with a screwdriver while the console was lifted into position. Installing the rear two screws was a simple matter of aligning the them with the holes from the factory roof light and fastening them.

Unfortunately fitting the factory reading lights to the console along with the sunglasses holder was not possible. I have ordered two eyeball type LED reading lights which I will fit at a later date.

With the roof console fitted, it was time for preliminary testing.

I have yet to decide on a touchscreen for the computer, so in lieu of this I used a standard LCD computer monitor and a USB mouse and keyboard to control the computer.
Console fitted with the computer up and running


I hooked up the computer in series with a multimeter set to ammeter mode to get a reading on the current draw of the computer. Evidently the computer is capable of drawing more than 10A, which tripped the safety circuit on the multimeter and caused it to cut power to the computer. However, I did manage to gather the following data between blackouts:

Max observed current: 7.3A
Current when computer is shut down: 0.06A
Current when computer is idling: 1-3A

These are acceptable figures, so I left the computer running continuously for several hours during the day to get an idea of how hot it would get. After approximately 4 hours of running in the shade on a 38C day (100.4F) with high humidity, I observed some worrisome results. Using Speedfan, a free and simple application for monitoring system temperatures and controlling fan speeds, I found the following:




There are several very high temperature readings listed, including the CPU. When I felt the case with my hand, it was very warm to the touch, to the point where the heat had conducted through the sides and bottom of the console (roughly 7mm of wood, foam padding and vinyl) to make them warm also. Better case cooling is required.

To rectify the problem, I will buy and fit two 40mm high performance fans to replace the ones mounted on the front of the case. In addition to this, I bought two 60mm fans and have fitted them to the black grill on the underside of the console. This idea did not work out as the fans would not fit on the grating without hitting the end of the PC when it was installed.

Mockup of 60mm fans which did not get used

Dust is a major concern as the car will be driven through muddy & dusty environments that are notorious for damaging electronics and mechanical components. I have some porous packing/cushioning foam from the box that the console came from, which I will fit between the fans and the computer to use as a filter.

In addition to testing the computer and checking the fit of the console, I also started to run the large amount of wiring and communications cables needed to support the computer. So far I have ran a thick ground wire to ground the computer and accessories such as the reading lights, a thinner red power wire for accessories, two 2 Meter USB extension cables and a figure 8 wire. One wire on this carries +12V that is switched with the park/headlights, and a ground wire that runs back to a variable dimmer unit. These will be used to run the LED's in the carling switches that I will mount in the switch bracket. I also ran two 4 core wires from the console down the passenger A pillar for future use with the switches.

Routing the wires from the console to above the glovebox (There is a compartment above the glovebox in the Patrol that will serve as an electronics and wiring bay) was relatively easy. I removed the A-pillar covers on both sides then removed the sun visors and passenger side roof handles. This allowed me to pull the roof lining down so I could feed the wires above it and leave them hanging out the open area where the switch holder on the console was (I removed it for easier access until I start wiring and mounting switches).
 

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Discussion Starter #4
Resolving Cooling Issues

As I mentioned in the previous post, the computer became very hot when running, so to combat this I have made a number of improvements to the cooling system.

Firstly I made a trip to my local electronics store and bought some heat sinks to augment the cooling of the computer's power regulators and internal controllers (MOSFET's), southbridge, and northbridge. The heat sink that I fixed to the southbridge came with thermal tape applied and it was a simple matter of peeling and sticking it on. Unfortunately it is a bit small, in hindsight I should have bought 4 for maximum cooling capacity.
Southbridge without cooler

Southbridge with cooler
Installing the northbridge coolers was a simple matter of applying some thermal adhesive to the underside of the four coolers and then sticking them on to the top of the existing cooler.
Northbridge with coolers

I improved internal airflow in the case by making a few tweaks to the cable management. I also installed extra wires for manually powering on and resetting the computer. These will be wired up to a DPDT Carling switch later on. I used wiring salvaged from an old PC case, as it was already twisted together and had the female connectors installed, so I could plug them straight into the motherboard.

Computer before cable management; the extra MOSFET coolers aren't installed in the is photo.

The computer in its entirety. You can see the mounting tray for the SSD on the top left.

Computer with cable management and extra wires for the manual power/reset switches ran out through the back. Note this photo was taken before the power supply cables were shortened.
The third improvement to the cooling system I made was airflow management. During initial testing I noticed that some of the air from the two 40mm intake fans was being blown backwards out the front of the case through two large holes for the hard drive and DVD drive. Since I'm not running an optical drive in the computer this is empty, presenting a path of lesser resistance for the air to exit the case, rather than flowing axially along and exiting out the exhaust holes to the rear.

Front panel of the case, the two 40mm fans have been removed until I receive the new high performance ones. The hole to the right is for the optical drive & hdd.
Looking at the picture above, air was flowing down through the two round holes and a large proportion of it straight up again through the two rectangular ones. Not very good for cooling the PC components at all. The solution I came up with was a simple one. I cut out a piece of thin plastic from some packaging, traced the holes onto it and cut it to size, making sure no screw holes were covered. Then I simply glued it onto the front plate.

Not the prettiest solution by far, but it should direct the air through the case, removing as much heat from the computer as possible.

The next tweak I made was to shorten the ATX power cables from the PSU to the motherboard. This will allow more airflow and easier reassembly of the computer, as the cables were getting caught as I slid the case over the tray.

Extreme cable management. Every cubic millimeter counts for airflow!

Aside from the cooling issue, other parts that I have ordered associated with the computer and console are arriving. I have received the two Narva LED map lights that I ordered to replace my Patrol's factory fitted map lights. While a little expensive, these units feature a 1 Watt Cree LED, similar to those used in LED lightbars.



I chose to mount the lights in the centre of the console as opposed to the traditional place of just behind the sunglass holder for two reasons; The first is that the lights would obstruct the line of sight of the driver & passenger looking at the switch panel, and the second is that mounting the lights in the console's centre have an advantage as to allow the lights to be directed forward (They swivel and tilt) for use as map/reading lights as well as backwards to illuminate the rear of the cabin.
 

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Discussion Starter #5
More Cooling Fixes

Today I received the cooling fans I ordered from Newegg.com and have installed the 40mm fans in the case. As mentioned previously the 60mm fans did not get used in the build.
40mm super-high airflow fans (left), and 80mm high flow fans (right)
Before installing them, I tested the 40mm fans, and I have to say for such a small unit they pack one hell of a punch!. Despite being very noisy (The spec sheet lists them as 54.5dba), they move an amazing 24 Cubic feet per minute. I couldn't find the specs on the original case fan, but the model up from it that draws more current and therefore has a higher rotation speed and CFM, is rated at 8.6CFM. Therefore the airflow capability has been increased by a factor of 2.79.


Upgraded 40mm fan (left) next to the fan that came supplied with the case (right)

Upgraded fan (left), and factory fitted fan (right)
I have no doubt that these fans will provide surplus cooling capabilities to the PC. However, it comes at a price. As I mentioned earlier the fans are very noisy (They rotate at an impressive 13,000RPM or 1361.36 Radians/Sec for any physics/mechanics buffs out there) and emit a sound akin to miniature jet engines, not ideal for situations when the PC will be used in quiet conditions (eg playing music when the car is parked). In order to reduce the noise level, I plan to fit a software/hardware solution to reduce the fan speed and therefore the noise. More on that in the coming posts.

I have made a final improvement to the PC's cooling system; I noticed the heat-sink for the MOSFETS was very loose and upon further inspection I realized that it was held on with two spring loaded screws, which were being compressed by the motherboard tray in such a way that the only thing facilitating thermal transfer between the MOSFETs and heat sink was a measly strip of thermal tape. This wouldn't do. I removed the heat sink and thermal tape and applied thermal adhesive to the MOSFETS (being careful not to apply too much) before replacing the heatsink and allowing time for it to set.
 

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Discussion Starter #6
PC Peripherals

So to meet the requirements I set in the first post, The PC needs to be able to have certain functionality added to it including:

  • -PC will need a fixed monitor that meets the requirements for in car use, more on that later.
  • -Input: Obviously a mouse and keyboard are impractical and unsafe for use in a vehicle, so a touch-screen will be required.
  • -GPS: The PC needs to know where it is in order to run navigation software
  • -Radio: A FM radio receiver will be required so I can listen to my favourite radio station while I drive
  • -Internet: A high speed internet system will be required with high gain antennas to get mobile internet on the go.
  • -Engine diagnostics: A module that plugs into the vehicle's OBD II port to read in real time engine statistics and clear fault codes.
  • -Additional media controls (volume, play/pause, next/prev ect): For ease of use while driving.
First thing's first, in order to be able to use the computer, it will need a screen. However, there are several requirements that it has to meet in order to be practical for use in the car. They are:
  • Automatic brightness control. The screen must be able to adjust its brightness either based on the ambient light around it (Similar to what most smartphones and tablets do automatically), or have a dimming feature activated by turning the vehicle's park lights on (like most automotive head units) This is both a convenience and a safety feature as a screen that is too bright at night will disrupt night vision, and a screen that is too dim during the day is just plain annoying and hard to read.
  • Capacitive touch input: This is a personal requirement, as capacative touch screen technology (Commonly found in all reputable branded smartphones and tablets) is far superior to resistive touchscreen technology. Not only does it provide much smoother and more responsive use, it allow for better screen viewing angles, multitouch and a glass coating that can be layered over the top for extra durability.
  • Automatic power on: The screen needs to turn on and automatically switch to the correct input channel when it receives power.
  • Sufficient brightness for daylight use
  • Size - the screen is not too large or too small for the car's DIN bezel (By my measurements the active screen size has to be between 165-205mm [6.5-8"] diagonal as the bezel can be cut to allow for a bigger screen)
  • Anti glare coating for easier readability in sunlight
  • Wide operating voltage range (roughly 10-18 volts to allow for voltage dips and surges)
  • Wide operating temperature range (roughly 10-50 degrees Celsius)
The screen I chose that meets all of these requirements is the Xenarc 700CSH. This screen (while ludicrously expensive) is a solid industrial grade unit that supports touchscreen control via USB and has acceptable resolution for its size. After all, the screen is the component of this build that I will see and use the most.

With the display and input requirements covered, it's time for the GPS:

I chose the latest and greatest in GPS technology, the BU353S4 (Now probably obsolete). This compact unit is not only IP rated to be splash-proof and dust proof, it has a handy magnetic base for attaching to ferrous surfaces (It conveniently sticks to the steel bracket built into the front of the roof console). Performance wise, it has the latest SiRF star IV GPS chipset at its core which is more than surplus to requirements for my needs.

For the FM radio I chose a cheap and cheerful RTL232U based FM radio+ DAB USB dongle. This unit supports digital TV and radio as well, but as it turns out finding a FM-only dongle these days is almost impossible. I will need to find a way to adapt the external antenna plug on the dongle to my vehicle's coaxial plug to use it with the existing FM antenna later on.

I still have not decided on a mobile internet router, as I will need to so some research on which system with which carrier will provide the best coverage at the best price. Until I decide on a solution I will use the hotspot feature on my smartphone. More on that in future posts.

I have ideas to upgrade the PC later on with other peripherals, such as USB HD video cameras for 24/7 security/dashcam recording and a dynamic control system for on-board lighting systems. These systems may bee fitted at a later date; right now I'm focusing on getting the car pc with the original requirements running perfectly.

As for the engine diagnostics, I have had no luck in the past trying to read fault codes from my vehicle's ECU. This is due to Nissan using a proprietary interface system known as Consult, which requires no-standard hardware to use. I am currently working around this problem and will post updates in the future.

I have integrated engine diagnostics into the computer, see posts #16 & 17.
 

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Very nice and well done. Department of Interior have been around a while, looked at their stuff before
 

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Discussion Starter #8
Software Selection and Prototyping

I have a small complaint about the the PC case, specifically the build quality of the 8 pin plug & socket used for the power, ground, acc and amplifier remote on cables. For starters not all of the pins are populated on the computer side, but on the plug there a couple of seemingly random wires installed. I cut these off as there was no way to use them. However problems started occurring during software testing as the other pins kept coming loose from the plastic plug & socket pieces, resulting in an unreliable and temperamental power connection to the PC. After unplugging and pushing the internal metal pins back in place only to have them pop out next time I plugged the plug in, I got fed up. I simply removed the plug and socket and ran heavy duty wires directly to the power supply, using male and female blade crimps instead. This an annoying and unnecessary modification, as the computer case should have been fitted with a better quality plug/socket!

Now comes the time for software installation. For the sake of not repeating myself and writing hundred page blog posts, I won't go into much detail about how I installed the software or why. I am not a software expert or a computer programmer but I do have an above average understanding of the windows operating system. So here we go:

To start the software prototyping and hardware testing phase I had the PC set up in my workshop using a standard LCD computer monitor, USB mouse and PS2 keyboard and some old desktop speakers. I powered the computer from a nearby parked car's battery, making sure to check the voltage periodically to ensure it could still start the car.

The first item was the GPS. I downloaded and installed the drivers using the link on the Ebay page from which I bought the unit. For GPS navigation software I used Navigator. It's a free GPS navigation suite that supports my GPS receiver. Installing it was a breeze, and it even had its own utility to automatically detect and use the GPS without any manual configuration. As a huge plus, it already has large touch optimized buttons which will come in handy for use on the smaller touchscreen.

11/15 Update: I am not using any navigation software on the computer as presently it is easier and better to use google maps on my smartphone. I was also unable to find good off-road navigation software as these days it comes pre-loaded with GPU units.


Photo of the navigation software. Mu aplogies for the poor quality.



Finding an application for listening to FM radio through my USB dongle was slightly challanging. I settled on Radio Receiver, which is a free app that actually runs through the Google Chrome web browser (chrome doesn't have to be running for it to work) to achieve real time SDR (software defined radio). Basically this means that the USB stick receives the FM signal and relays it as a raw digital signal to the app, which then processes it into an audio signal and pipes it out of the computer to the speakers. There are a huge amount of apps out there for doing this, as it turns out the USB sick I chose (there are many out there similar to it) is capable of receiving a huge range of signals (including analogue and Digital TV, Digital radio and UHF signals used by aircraft for communications). For my application I needed something that was simple, only received FM radio, was touch friendly and could be activated with one or two taps, hence why I used a simple app rather than a full software suite.

11/15 Update: In post #20 the dongle became faulty and I had to replace it with another one, which led to an interesting discovery.

Getting Radio Receiver to work with the USB stick was problematic as I had some issues in getting the PC to recognize it. To get it working I used an utility called zadig. Zadig is basically a program that replaces the generic drivers for the USB stick with better ones to allow the USB reciever to work properly. After doing this and restarting the PC there were no more issues with Radio Reciever.


Radio Receiver in action

For power saving and general monitoring I'm using AI Suite 3. This is software that came with the motherboard and is handy for fan control , and active power saving by dynamically limiting the CPU power consumption. This will be handy for extending battery life when the PC is left on wile the vehicle is parked.
 

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Discussion Starter #9
Screen Testing and More Software

Good news, yesterday the touchscreen arrived!







For more specs see the link in the text above

After unboxing the unit i was eager to test it with the computer.
Front view of the screen, the three round holes in the lower center area are for the IR remote control, ambient light sensor and power indicator LED, respectively.
The unit is solidly built and overall feels like it is very good quality.
Rear view of the screen with the supplied malleable copper base attached. on the lower left you can see the area where the proprietary multi plug for the inputs and outputs goes, and the hole for the power connector.

Straight away I noticed that Xenarc didn't skimp on the accessories. The unit comes with mains and 12V cigarette power adapters, a DVI to HDMI converter (which I will be using later), a driver CD, an extra U-bracket for securing the main pug to the screen (this will be handy to prevent vibration from loosening the plug), a full featured remote control and of course the stand and large main plug.
Other end of the main wiring harness plug. the connectors are: 3.5mm (for carrying audio to the inbuilt speaker), two RCA video plugs, an RCA audio plug (for mono audio), USB (for supplying the touch screen signal to the PC), HDMI and VGA. If I had a bone to pick with this layout it would be that there were no dust-caps supplied for the plugs that won't be used (Ie everything except HDMI and USB).
Setting up the unit was as easy as attaching the stand and plugging in the main wiring harness and power plugs.

Testing set-up, the larger monitor in the background is no longer needed

Adjusting windows to work properly with the display took a little bit of tweaking but overall it was a relatively simple process. Getting the resolution correct was somewhat challenging, as the monitor's native resolution of 1024 by 600 pixels was not supported by the Intel HD graphics built into the computer's CPU. However the screen supports many different resolutions, so to work around this I set the resolution to 1920 by 1080 (1080P HD) and then configured windows to have extra large (250%) Windows and text for easy use on the touchscreen. Interestingly when I tested the screen at 1280 by 720p resolution, windows disabled the mobile (RT) apps stating that the resolution was too low to run them. Strange.

I made the mistake of installing the touchscreen's supplied touch driver software, however this was not needed as the driver software (which comes with a fully featured software suite) emulates a USB mouse and therefore Windows would not recognize it as a touchscreen. This meant that all the touch features native to windows 8.1 would not work. To fix this I simply uninstalled the drivers and software suite and let windows automatically install generic drivers. From then on I had full multi touch support and access to the gesture based windows features.

Using the touch screen feels as responsive and smooth as as using a brand new Android or iphone. Being capacitive, no pressure on the screen is needed to register a touch, and multitouch pinching and zooming works flawlessly. I have no regrets in spending the extra money on this monitor over inferior resistive touchscreen technology though I do believe Xenarc has the monopoly as it was the only capacitive one I could find.

The monitor's built in OSD (on screen display menu) has a few handy features, other than the standard brightness, color & contrast adjustments; you can disable the hardware buttons on the front of the screen, disable the extra (VGA, RCA, ect) Inputs, turn on or off the automatic brightness adjustment, and tweak many other features.

Testing the screen with Google Chrome was a pleasant surprise, as Chrome has inbuilt touch-screen support. Pinch to zoom, forward and back navigation by swiping and easy tab changing are all supported.
Chrome running on the touchscreen
To improve its ease of use, I installed an extension called Speed Dial 2. Its basically a replacement homepage that lets you configure it to have links to your favourite websites with large icons (pictured above).
 

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Discussion Starter #10
Screen Installation

Today has been a massive day in terms of progress. With some much appreciated help, I have fitted the screen to my Patrol by building a custom bracket and trimming the factory bezel to fit the screen.

To start off with, I'll provide a list of the materials and tools used for the build. All materials were purchased from my local hardware store (bunnings) and are readily available.

Galvanized steel, note it is L shaped.

I used a long (roughly half a meter) piece of 2mm galvanized steel pre-bent into a L shape. It turns out the spaced pre-fabricated round and diamond shaped holes would be a huge advantage later on.




For fasteners I chose 316 grade stainless steel M6 bolts, contact washers and locknuts. The bolts coming loose from vibration was a key concern for me so I decided to use contact washers for extra piece of mind. I also bought a small bottle of Locktite 202 thread lock and some stainless M3 washers (not pictured). In summary, the materials used for the bracket are:
  • 500X100X2mm Galvanized steel L-bracket
  • 4X M6 Stainless Steel Bolts
  • 8X M6 Stainless Steel Contact Washers
  • 4X M6 Stainless Steel Locknuts
  • 4X M3 Stainless Steel Washers
  • 1X Bottle of Locktite 202 Threadlocker

The tools I used are:
  • Screwdriver (Philips Head)
  • Long fine tipped Philips head screwdriver
  • 10mm ratchet spanner
  • 10mm spanner
  • Drill & Drill bits
  • Hammer
  • Vice
  • Flat medium file
  • Round medium file
  • Angle Grinder w/cutting & grinding discs
  • Ozito rotary tool (cheaper alternative to a Dremel)
  • Ruler
  • Pencil
  • Bench vice
The challenge was to find a way to mount the screen in place of the after market double DIN form factor head unit.

After market DIN head unit (note the two steel brackets that screwed in on either side of it are missing) and I'm holding it where it originally sat for the photo with one of my fingers.

Cavity where the head unit sat. The wiring on the right is for the switch for my reversing lights.

After some thought and planning, I decided not to not use the stand that came supplied with the screen as there are no solid places to mount it in the cavity where the head unit sat. Instead we made use of the four M3 screws on the back of the screen that are presumably there to fit a stand/bracket.

The back of the screen with the four M3 screws. The black bracket in the centre is for the supplied stand and won't be used for mounting the screen in the car.

To start off with, I cut off two pieces from the L bracket with the angle grinder and filed the edges to smooth them. In a huge stroke of luck, the spacing of the prefabricated holes lined up almost perfectly with the screw holes on the screen. After drilling out the holes to a slightly larger diameter, fitting the brackets to the screen was simple.

screen bracket without the holes drilled out to suit the M3 screw holes.

To secure the brackets to the vehicle, I measured and cut another section of the L bracket, then bent it flat using the hammer and vice. Then I drilled holes in the now flat plate to coincide with the holes that were originally used to mount the head unit.

Backplate mounted using the head unit holes. Note drilling extra holes for the two plastic locating pins was slightly tricky as marking them from behind was impractical.
After doing some mocking up and approximate measuring, I decided to bend the two brackets for the screen by 90 degrees and bolt them straight onto the backplate. Any small errors in spacing could be fixed by bowing the screen brackets in slightly to adjust the distance of the screen from the backplate. Tilting the screen at an angle to position it more perpendicular to the user was not necessary as the viewing angle of the screen is excellent.

Screen with the two bent brackets installed. Note the holes on the screen brackets are drilled out to accommodate the M6 bolts.

After fitting the M3 washers and locktite to the screen bracket screws, It was time to mock up the screen on the backplate again using the plastic bezel for position reference. It became clear that the top two plastic slots that house the bezel clips were interfering with the screen's fit, resulting in a gap between the top edge of the bezel and the screen when installed. Consequently, the bottom part of the screen that houses the buttons, light sensor, ect was completely covered by the bezel. To rectify this I used an angle grinder to remove the inside bottom corner of each slot to allow the screen to snugly fit between the slots. Fortunately this did not interfere with the function of the bezel clips as the clips used the vertical sides of the slots to grip and not the corners.
One of the plastic slots with the inside edge removed.

After this was done and the screen checked for fit again, it was time to position the screen and mark out the holes to attach the screen brackets to the backplate. This was a difficult two person process that involved one person holding the screen against the backplate, while the other positioned the plastic bezel in place to check the position of the screen, then adjusting the screen's position by hand until it was successfully aligned. Then a graphite pencil cut approximately 5mm long was used to reach in behind the screen and mark through the screen bracket holes onto the backplate. This was especially difficult as during this process the screen could not be moved and had to be held in place by hand.

After the holes were marked I used the drill to make four holes through the backplate. Then I removed the backplate from the vehicle, and bolted the screen onto it.

Once the screen was secured to the backplate, the whole assembly was then secured back onto the vehicle using the four factory screws originally used to secure the head unit.

screen secured to the vehicle

Some final adjustment was done by using the plastic bezel for reference and the screen mounting was then complete. In order to make the plastic bezel fit back into the dashboard properly, some cutting was required. This involved using a combination of the angle grinder, flat and round files and dremel tool to take away material where necessary until a snug fit was achieved. Unfortunately when cutting the plastic bezel the angled corners of the bottom of the screen was not accounted for, resulting in a slight gap at the bottom corners.

Overall the fit turned out to be quite snug, and the screen feels secure in place and won't move from vibration when the car is driving. I am quite pleased about the design of the bracket as it is just as easy to remove as the factory head unit, as it uses the same four screws to secure it to the vehicle.


The final product with the screen fitted.

After the screen was fitted, it was time to prepare the computer and console for fitting to the car. Back at my workshop I removed the computer from its testing arrangement and screwed it back onto the console using the four large wood screws.

In order to manually power on and off and reset the computer (the computer's power supply has a configurable system that has an on and off delay based on a wire that will be connected to the accessory position on the ignition, a power/reset switch is required. I used a Carling rocker DPDT (Double Pole Double Throw) switch, so that using the single switch I can power on/off the computer or reset it (in the unlikely event it hangs or crashes).
DPDT Carling switch installed in the console's 6-switch holder. I will order a custom made laser etched labelled cover for the switch later.

After connecting the wiring for the power/reset switch, ground and crimping the terminals for the computer power, map light power and ignition signal I did some cable management.

Managed cables
Special thanks to Dad for helping me with the screen bracket ;)
 

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Discussion Starter #11
Computer Installation

Naturally, there was a lot of wiring that needed to be installed in order to get the computer working, so to keep things concise I won't go into detail about every terminal connection I installed.

In order to save time on installation, I decided to run all of the wiring first before installing the computer. This worked quite well and saved me a lot of time.

Seeing that the head unit was replaced in the previous post by the touchscreen, An amplifier was required to drive the four satellite speakers. I found a second-hand one on Gumtree and bought it for $35, a good deal by any standards.
Second hand amplifier. It is old but still works without any issues.
Unfortunately the amplifier was designed in such a way that it has four RCA inputs; one to drive each speaker and it does not have internal bridging, meaning that four RCA channels are required to drive all four speakers. In addition to this I needed another two RCA outputs to drive my subwoofer amplifier. To solve this problem I made a trip to my local electronics store and bought four RCA single to double adapters and a couple of RCA plugs. I made two short RCA cables from the plugs and an old RCA cable to go from the adapters to the other inputs, and used the double adapters to allow another two inputs for the sub woofer. This is a temporary measure as I will eventually buy better amplifiers with built in pre-amps.

I extended the wires from the factory head unit harness down under the font passenger's seat to where the amp is housed.

Wiring the power to all of the amplifiers was relatively straightforward. I have created a rough circuit schematic to show how power is delivered to the system as a whole:
Rough circuit schematic. The box on the far left is the passenger's side A-pillar where the wires are ran up to the roof. The box above and to the right is the compartment above the glovebox where all the excess wires are stowed. The battery in the schematic is the auxiliary battery, the main battery is not shown. Also note that the earth connection for the main amplifier is missing. The two round dots forward of the PC are the two interior lights.

Running the wires was simple enough, The passenger side A-pillar cover was removed along with the door seal and roof handles revealing plenty of room to run wires along the steel pillar up to the roof.

Passenger A-pillar with some of the wires installed


Compartment above the glovebox with some of the wiring installed. The fuse on the right protects and splits the wires to power the computer and the 4 channel amplifier.

in addition to the power wires, the following other cables were ran;

  • 2X 5M USB extension wires, one for the touch screen data and another for the OBD2 interface
  • 1X 3M HDMI extension lead for carrying the video signal to the screen. Note I used a HDMI to DVI converter to take a DVI signal from the computer as audio was not needed. I also used a HDMI female to female adapter to go from the male end of the extension cord to the male end of the HDMI plug from the screen's main wiring harness.
  • 1X 5M 3.5mm stero to 2X RCA cable to carry audio from the computer to the amplifiers
  • 2X Signal wires for powering on the amplifiers (in schematic above). Note these come separately from the computer as the computer turns the amplifiers on once it has booted.
  • 1X 4 core wire for accessory switches on the console
  • 1X single core red wire for misc. accessories. This was not used
  • 1X mini coaxial wire connected to a magnetic antenna for the FM radio. Until I buy the adapters to adapt the factory radio to the USB receiver stick I am using a small antenna mounted on the roof above the passenger side door.
With all the wires ran it was time to make final preparations to marry the computer to the car.


Computer in console with the wireless bluetooth and wifi antenna (left) mounted




Computer and console ready to be mounted.

With some help, the four screws were installed and the console mounted to the roof once more. This was a slightly difficult two person process as lining the screws up was tricky due to their vertical position.

Console installed. The hole at the from which the wires are hanging will be covered with houses the factory interior light.
Once the rest of the wires were connected the computer was ready for a first test. After a few small tweaks and cable management the computer was fully functional.

Unfortunately during testing an annoying problem occurred with the screen. One of the buttons on its front got stuck behind the face plate, resulting in it becoming unusable and the unit looking broken. In order to fix this I had to remove the screen from its brackets and take it apart in order to fix it. I took this opportunity to do a quick tear-down to see how it worked. After carefully unscrewing it and fixing the caved in button I took a couple of snaps of the main driver board. It turns out that the button had slipped off of the micro-switch that it normally rests against. The cause of this was probably the screen not sitting quite right in its bezel in the dash, resulting in the surround applying pressure on the scree's bezel and forcing the button off the micro-switch.

Main driver board for the screen
After carefully reassembling the screen with locktite on the screws, I fastened the bracket onto it once more and readjusted its fit in the bezel so there was no pressure on it. This should stop this from happening again.

The whole install of the computer took me one whole day starting at roughly 8am to finishing at 5pm.

With the computer Installed and functioning, The next stage is to work out the software side of things. I am still doing a lot of testing and configuring on that front. Until I have made a lot of progress and am happy with the way it is running.
 

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Discussion Starter #12
Field Testing and Tweaks


Hello and welcome to past #10 of my blog on how I built my own in-car computer based entertainment and vehicle management system. In this post I will discuss the various tests I put the system through and how it fared.

This past Easter weekend I took my vehicle to a popular camping and 4WDing spot located around a large irrigation water dam. The area includes hilly terrain, bumpy gravel tracks, water crossings, rock climbing, mud flats and muddy holes. I drove my Patrol through each of these multiple times.

My Patrol parked atop a hill climb overlooking the dam. This is an old photo and it has many more things bolted to it now.

I'm extremely pleased to report that I experienced no hardware faults of any kind with the computer system at any time during the weekend. This was the first real field test for the hardware and everything functioned exactly as it should from a hardware standpoint.

However, there were a couple of minor bugs with other parts of the system, specifically the four channel amplifier that drives the satellite speakers. While there were no problems with listening to music at very high volumes (this was tested for an extended period of time), on the second day the music cut out unexpectedly while driving. Closer inspection revealed that the amplifier's inbuilt protection system had activated, probably due to overheating. The problem soon cleared itself an hour or so later and has not returned.

There are still many software issues to sort out which i am still working on.

The next hardware fix I am working on is to improve the FM radio reception through the USB SDR dongle. Currently RF signals are received through the small magnetic antenna which is magnetically attached to the roof, but this is not sufficient for receiving signals far away from suburban areas. To rectify this I have ordered a series of adapters to transmit the signal from the vehicle's factory fitted electric antenna up to the computer and the USB reciever dongle.
Here is a list of parts that I ordered to do this.
In addition to ordering the adapters I have rigged the electric antenna to raise up via a manual carling rocker switch mounted in the roof console.
 

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Discussion Starter #13
Cooling Tweaks, UI and FM Improvement

It has been quite a while since my last post; work on the project has slowed due to other commitments taking priority. However significant progress has been made since my last update. I have been tweaking and improving the system to optimize its performance and ease of use. I also performed a full inspection on the internals of the computer to check for dust. More on that later.

The first major improvement to the system was the cooling. Orignally, I used a software/hardware system called Corsair Link was to run the cooling system. This is a software controlled hardware based system that is versatile for controlling large system's fans and lighting. However, after reviewing its performance I decided that it was surplus to requirements, as there was a better alternative available. This came in the form of the motherboard's on-board fan controller, which works with the software suite supplied with the the manufacturer. I decided to remove corsair link and instead run the fans directly off the motherboard headers. This change proved beneficial as the ASUS software system does a very good job at controlling the fans and actually runs the computer far quieter than Corsair Link.

However, to achieve this the console needed to be unmounted from the vehicle, the computer removed from the console, and the fans rewired to the motherboard headers.

Computer stripped apart. There is no significant dust build-up in the case or on the components
The wires from the left hand fan needed to be extended to reach the motherboard header but other than that the modification was very straightforward.

Empty rear section of the console where the corsair link controller was
Once the computer was remounted to the vehicle, I uninstalled Corsair Link as it was no longer needed and also interfering with the Asus software. After that, I opened Asus AI suite 3 and selected Fan Xpert 3 (The proprietary fan control software) and activated the auto tune feature. This automatically tunes the fans for specific purposes and gives the user four modes to select how loud they want the fans to run.
Fan Xpert Softwware tuning the fans
After the automatic tuning was complete the system now manages itself and will automatically adjust the CPU and two case fans to keep the CPU temperature within operating limits.

Much more attention has been paid to the quality of signal cable running through the vehicle and avoiding interference. The second major modification made to the system was to improve the FM radio signal quality. Previously I was using the small magnetic base antenna that came with the USB dongle to receive FM radio signals. This was hopelessly inadequate to the point where the radio was unusable.

As discussed in previous posts, I ordered a complicated system of cables and adapters to adapt the vehicle's factory FM plug to a common plug, extend it up to the roof-space then adapt it again to the small MCX plug on the dongle. This was a doomed system from the start. Instead of fitting it, I enlisted the help of some friends in the communications industry. They used crimp connectors and a coaxial cable to extend the factory wiring harness, then terminated the extension in a standard BNC fitting.

Terminated BNC fitting with coaxial cable

From the BNC fitting in the photo above, a BNC-MCX adapter cable plugs straight in to the USB dongle. In addition to running a quality coaxial cable to the dongle, the dongle itself was relocated to behind the computer via a USB extension cable. This has also improved signal quality as the coaxial cable ran next to the power cables for the PC and was causing interference.

To complete the system, I also wired the factory electric antenna to a switch mounted overhead in the the switch holder to manually extend and retract the antenna.

A major improvement to the windows UI has also been made. The desktop layout of windows was insufficient, so I found software to replace the windows shell with a more touch friendly version. This comes in the form of Thinix Touch. I am still configuring the system as it has many many settings to configure. More on that in later posts.

Further attention has been paid to cable management and isolation of signal cables from power cables. When rebuilding the computer the power and signal cables for the GPS were separated.

Rebuild console. Note the signal cables for the Wifi/BlueTooth and GPS reciever are separated.

The dual band Bluetooth/Wifi antenna has been relocated to the front of the console. However, there have been significant interference/bandwidth problems with bluetooth from the start. If a wifi connection is active on the car computer while bluetooth is streaming audio, it causes the bluetooth to badly stutter and lag. To fix this problem I have decided to buy a USB Bluetooth adapter and run Blutetooth completely separately via a separate antenna. More on that in later posts.

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Finally, problems have arisen in the low quality cable used to run audio from the PC's 3.5mm plug down to the amplifiers. Interference can be heard through the speakers if the cable is not properly positioned. To rectify this I will replace and rerun the cable with high quality leads. And instead of using the 3.5mm plug I will use the RCA ports on the front of the computer case.

I would like to thank my friends for helping me with the coaxial wiring and assisting with the computer rebuild. Your help is much appreciated :)
 

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Discussion Starter #14
USB3 Hub Installation and rework of audio cable.

In this post I'll cover the reasons why, and how, I integrated a USB3 hub into my vehicle. I also replaced the signal cable that runs from the computer to the amplifiers. This post will be slightly more brief than the others as I don't consider it a vital part of the build, and I have some catching up to do on other progress that has since been made on the system.

Finished product


The hub I installed is a four port high speed USB3 hub which supports an external power supply as well as power from the host computer. It has four switches to individually power up the USB ports.

Parts List (From eBay):

(From local electronics store):
  • 2X Round SPST switches (though one of any switch will do)
  • Wiring and crimps
  • 4X 10mm M2 stainless screws, nuts and vibration-proof locking washers
  • Electrical Tape
Tools needed:
  • Solder, soldering iron, ect.
  • Dremel or die grinder
  • Drill
  • Marking pens, scribe, rule
  • Screw drivers
  • Bench grinder
  • Pliers, side cutters, ect.
Reasons for fitting the hub:
  • Increased potential for charging phones and devices. USB3 supports a maximum current of 900ma though with the use of an external power supply this can be greatly increased
  • Ease of access for plugging peripherals into the computer - Plugging in USB mice, keyboards and other interface and/or storage devices is somewhat difficult due to the concealed nature of the computer overhead in the roof console
  • Increased transfer speeds for storage operations such as copying movies or TV shows to/from the computer onto storage devices
The hub is located on the back of the center console (the armrest/storage container located between the front seats) and will replace an existing system that I fitted a couple of years ago. The old system had four USB2 ports for charging devices, a cigarette lighter port for light duty power applications and a light for ease of use in dark conditions. In the coming photos the holes for the old components are obvious. The new hub covers these up nicely.

The first step was to isolate the power source to the back of the console then disassemble the back of the console. On my vehicle (GU Nissan Patrol) there are four screws holding the back of the centre console on and a couple more that hold the hinged lid on. All of these were removed to expose the back of the console, then I removed the console back plate from the vehicle and took it to the workshop.
Inside of the console with the old wiring present
I removed all of the old wiring bar the positive and negative connections coming into the system from the battery, then removed the old USB2 ports and cigarette lighter socket.

Back view of the inside of the console. The holes for the old USB2 ports and cigarette lighter are clearly visible. Also note this is a rear view of the finished product, the usb and power input cables are visible at the bottom of the photo.
The next step was to mock up the position and fit of the USB3 hub and design a way to mount it securely to the console. The hub easily disassembled via internal plastic tabs into three main components; the case, the backplate and the circuit board. I started by placing the backplate flush with the console then placing the case on top. It became clear that due to the shape of the centre console and the angled sides of the flat plate some material would need to be removed to ensure a snug fit and to allow the two cables to pass through the left side of the console and into the hub.

Note the angled sides of the plate where the hub has been fitted. Material was removed on the left side to hide the plugs.
I progressively drilled out then sanded away the plastic of the console with a drill and die grinder, regularly checking the fit until I was satisfied that the hub would fit nicely. Once that was complete, the next step was to make sure that the power input and USB3-B type plugs would fit without intersecting the back of the console. USB3-B is the current plug standard for high end smartphones and it incorporates the old USB2-Micro B type plug with a USB-3 micro plug. It became clear that the plug end of the supplied USB3-B cable was too thick to fit properly and was putting stress on the solder joints of the socket on the PCB. To resolve this problem I carefully sanded off the plastic outer casing of the plug end with a bench grinder until the wires and solder joints were exposed. I wrapped the lot in electrical tape to insulate it. I also used the grinder to create a flat face on the power plug as well.

PCB with the modified USB3-B plug inserted.

Once I was satisfied that the plugs would fit properly I carefully inspected the back of the PCB and backplate to find places to drill holes for the mounting screws in places that would not hit the underside of the PCB and cause short circuits. This was slightly tricky as in addition to this the holes must avoid the empty space underneath where the old components were installed in the console. Once I was satisfied I could securely mount the backplate to the console I drilled the holes in both the backplate and console and fastened the M2 screws.

Back view with the backplate mounted and the screws fastened
Moving to the front side the console I applied tape over the screw heads to prevent shorting on the PCB.

Backplate with tape over the screw heads. Note that the two screw holes at the bottom (the console is upside down in this photo) need to be accessed later to fit the console back to the car. Luckily the chamfered edge of the hub made this possible without removing the hub.
I then assembled the power plug by soldering two wires onto it and plugged it into the PCB along with the USB3-B plug, then fitted the PCB to the backplate and case onto the backplate. I trimmed the sides of the two switches on the bench grinder to ensure a snug fit.

The next step was to test the hub for correct function. To do this I used a car battery and an adjustable step-down converter, set to 5V (The standard voltage for all USB interfaces).

Testing the hub
After I was satisfied the hub was working properly It was time to wire the assembly into the car. The old system I used to power the USB2 hubs used two of the adjustable voltage regulators pictured above stacked on top of each other and wired in parallel, but testing revealed that the current output was insufficient and there was an issue with the two regulators "Fighting" each other for current suply. This was caused by minute voltage output differences between the two regulators which resulted in a high pitched whining sound coming form both regulators; an interesting phenomenon.

Old power supply system

To rectify this I fitted a sealed high output step down converter that I had as a spare.



On my vehicle there is a convenient plastic rail inside the console which made mounting this very straightforward.

DC-Dc step down converter mounted on plastic rail
Once the converter was mounted I carefully wired the its +12V input wire to the top switch, ensuring the 5V output leads were correctly connected to the hub via the plug I assembled earlier (12V supplied to the hub would probably cause it to explode!). Since there was a second switch left over from the old system I added a LED bar light as an afterthought just so it would do something.

LED bar light mounted on console
The next step was to do some cable management and run the USB3 extension up one of the pillars and through the roof to the computer.

System powered up with the bar light shining brightly. Note an ashtray goes in the centre of the console but due to my USB3 extension being delayed in the mail I left the USB3 cable hanging out of it until I could fit it.
The final step was to fit the console back onto where it belongs and do a final current output test if the system using my in-line USB current/voltage monitoring device and a large load. The system performed flawlessly.

Final current output test. Note the system is probably capable of more current output but due to the limitations of the load I was using this was the maximum I could get out of it.

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The next tweak to the computer system was to improve the reliability of the audio cable which supplies an audio signal from the computer to the amplifiers. I originally used a 5M long 3.5mm to RCA jack, but I inadvertently ordered a poor quality cable with even poorer quality plugs fitted to it. Consequently both plug ends of the cable were extremely temperamental and would regularly cause feedback from the computer to play through the speakers or simply not work at all. This problem gradually became worse over time.

To fix this I bought 6M of high quality signal cable from my local electronics store along with two sets of male RCA plugs. I then soldered one pair or RCA plugs to the computer end of the cable (I changed the interface from 3.5mm a stereo plug to RCA plugs as the computer's case has RCA outputs connected to the front panel output header on the motherboard). After that the old cable was removed and the new one ran in its place. It was then cut to length and RCA plugs attached to the other end before plugging them into the amplifier.
 

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Bluetooth fixes and software improvements

I have made to improve the performance of the Bluetooth system and various software components.

To start off with, I use the system to wirelessly stream music from my smartphone to the computer via Bluetooth. However from the start this functionality has been glitchy. The audio stream is not smooth an continuous as it should be, rather it stutters and occasionally stops working for lengthy periods.

The cause of this is not fully known as I lack the proper instrumentation to find the source of the problem. However based on the symptoms of the problem it is clear that there is some sort of interference affecting the 2.4ghz wireless Bluetooth signal which results in disrupted communication between the smartphone and computer. This could be due to the poor placement of the PCIe wireless communications card on the motherboard (though ASUS had little choice due to the very compact form factor of the board), which is very close to the rear panel and is known is known to be affected by nearby USB3 ports and controllers which run at the same frequency, or possibly EMI or back currents from another source. Another possibility is the dual antenna that came supplied with the motherboard could be faulty. Either way it is not acceptable.

After much deliberation I decided to rectify the problem buy buying a USB Bluetooth 4.0 dongle and disabling the motherboard's on-board Bluetooth. This turned out to be problematic however as there were driver conflicts when installing the new drivers for the dongle. I disabled the on-board Bluetooth in the UEFI BIOS, but despite this the drivers and software suite supplied with the dongle were installing for the on-board Bluetooth. The net result was that the Bluetooth dongle was not recognized by its drivers and the bluetooth utility in the system tray was unable to activate bluetooth due to the on-board Bluetooth being disabled on a hardware level. Uninstalling the drivers and reverting to the default windows drivers did not yield results either. The dongle would be visible to my smartphone but would not connect as windows was not allowing incoming connections.

I made many frustrating attempts to fix this without success. I turned to a friend in the IT consolation industry to help me with the problem. With the aid of remote access via Teamviewer and a patched in data hotspot connection via a smartphone he was able to reconfigure the software and drivers for Bluetooth and restore full Bluetooth functionality to the system, all from sitting at his desk more than 30km away. Needless to say I was impressed.

After the bluetooth problem was solved we met in person to fix a few other things. including the the functionality of the FM radio system. The USB tuner dongle I chose is capable of much more than just FM radio, thanks to the powerful RTL232U tuner chip at its core. We installed a DVB-T tuner program on the computer to add the capability of digital TV to the computer. However due to ongoing driver issues and the non-TV optimized antenna on the vehicle this is a work in progress.

A few other performance tweaks were made. We are planning further software tweaks to improve the ease of use of the system. More updates to follow. I would like to extend a huge thank you to my friend for helping me with the project.
 

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Discussion Starter #16
Hardware Volume Control Knob Configuration and Windows Upgrade

In this post I'll cover a few major changes that were made to the computer's software, and an important and vital hardware addition.

To start off with, I'll outline the situation with windows. It was deemed necessary to upgrade from windows 8.1 to windows 8.1 pro, because of the extra features and native remote desktop functionality it provides. Achieving this was a huge effort, however, as using the "upgrade" option on the virtual installation disc downloaded from Microsoft didn't work.

Once windows was reconfigured and all the drivers and hardware working properly, it was time to address a major usability issue that was outstanding on the computer since its first use.

Trying to adjust the volume while driving is extremely difficult. On windows 8.1, the easiest way to change the volume was to bring up the charms menu by swiping from the right side of the screen then tapping settings, then tapping and dragging the volume icon to the desired level. Not ideal at all. A tactile system was needed - ie a volume control knob akin to what almost all conventional car head units have.

To achieve this, I decided on a fully digital solution, rather than simply wiring an in-line volume control knob in series with the recently reworked RCA connection system (see previous post). The advantage of this is the volume can still be remotely adjusted from phones and there is the added redundancy of still being able to adjust the volume using the method outlined above.

After some searching I found this little gem, a rotary encoder based volume control knob that was designed specifically for in-car PC applications. One order from amazon.com and two weeks later and it was delivered to my door.

The unit itself is relatively simple. It connects to the computer via the supplied USB cable and will work with windows out of the box to control the volume without any need for driver installation. While not cheap, the unit seems to be of good quality and is thoughtfully designed.

Turning the glowing knob adjusts the volume, and pushing it mutes all audio. In addition to this, it is backlit with a RGB LED and is able to be set to any color via software downloadable from the manufacturer's website. The blue power LED (see above photo) is also fully dimmable.

However, windows does not support the drivers for the LED control functionality, and manual driver installation was required. The supplied instructions asked me to manually install the drivers using device manager in Windows, however on windows 8.1 pro this proved difficult.

Windows 8.1 would not let me install drivers that are not digitally signed (the unit comes from a small developer who for one reason or another has not signed his work), so It was necessary to activate the advanced start-up mode in Windows and disable the driver signature enforcement setting. I used this tutorial to achieve this.

However, this caused further complications, as an unknown error was preventing windows from rebooting into advanced start-up mode

This error would appear during restarting right before the PC power-cycled itself, giving me about 1.5 seconds to read it before the screen went black. The PC would then boot up normally into windows after instead of launching advanced start-up. This is an extremely frustrating and potentially dangerous condition as if there was an fault preventing windows from booting advanced start-up would not automatically launch, leaving me little options for recovering the PC.

After consulting my IT professional friend and some forums, I tracked down the cause of the problem. The CSR wireless Bluetooth stack software supplied with my bluetooth dongle was causing a windows C++ runtime error. To fix the problem, I had to uninstall the wireless stack and drivers, launch advanced start-up, disable driver signature enforcement, install the LED control software driver then reinstall the Bluetooth stack and reconfigure the dongle. A lot of work for such an arbitrary error!

Once the drivers were installed, the volume control knob was fully functional.


LED control software
The simple but effective software allows the user to pick any colour or brightness for the volume knob to glow, and control the brightness of the power LED. This only needs to be done once, as the program saves the settings in the unit's on-board micro-controller. Also Included in the software pack is the ability to flash new firmware to the volume control knob.
 

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Discussion Starter #17
Volume Knob Fitting & RCA Rework

This post will cover how I mounted & permanently installed the volume control knob system from the previous post, and briefly some further improvements and functionality upgrades.

It should be noted that the black machined knob pictured below was not sold with the kit and was purchased separately from Amazon - you can find it in the "people who bought this item also bought..." section.

As discussed in the previous post the volume control knob is fully functional with the computer; the drivers set up and the led's configured to how I want them. To mount it onto the vehicle, I made a trip to my local electronics store and bought some stainless 25mm M3 screws, anti-vibration washers, M3 nuts and some threaded nylon spacers.


The first step of installation was to find a suitable place to put the knob. Keeping with a more traditional layout I chose to mount the knob on the bezel that surrounds where the head unit was located. There is plenty of clearance behind the panel and running the USB cable was easy. The driver and passenger can easily access it here.
Unfortunately, M3 was the smallest size screws/washers the store sold, so I was forced to drill out the holes in the PCB to suit the screws.

Back of the PCB before drilling
PCB after drilling
Fortunately, due to the excessive thickness of the PCB doing this did not damage the board or any circuitry. The next step was to mark and drill the centre hole to mount the shaft of the rotary encoder, checking for clearance around and behind the bezel.

Then the PCB was test fitted to the panel, and the positions marked and drilled for the four centre screws

Centre hole and four holes for the corner holes. Note the distortion in the hole positions is a result of the curved shape of the bezel; the board was test fitted so that the encoder was parallel with the computer screen and not the bezel
The volume control knob was then fitted to the panel, adjusting for fit to make sure the knob aligned parallel wit the screen.

Rear view of the PCB with USB cable attached
Top view
View before fitting the bezel
It should be noted that there were some slight clearance issues with getting the mute function to work properly with the knob (the knob must be pushed in for it to work). There was too much clearance between the end of the rotary encoder and the inside of the knob, resulting in the bottom of the knob touching the screws and bezel before it could push the button built into the encoder. The solution to this was extremely simple: I inserted a conveniently sized screw inside the knob which acts as a spacer.

Screw inserted into the knob to fix the mute issue
Overall, I am very pleased with the functionality of the system. It works as intended and is very responsive. However the glow of the LED knob is somewhat covered. this is not a big issue as light shines from behind the knob in the dark, making it bright enough to find at night but not too bright so as to cause a distraction when driving.

System with the knob removed to reveal the glowing rotary encoder
In addition to installing the volume knob, I also ran the 4 meter USB 2.0 extension cable from the computer down the passenger side A-pillar, as well as a 5 meter USB3 extension cable along the same route. This USB3 cable runs inside the centre console to the USB3 hub installed on the back of the console. The hub is now fully functional and makes plugging devices such as mice, keyboards and storage much much easier than reaching inside the roof console to connect them.

Back of centre console with USB3 cable connected

The last main point of work for this post was the reworking of the RCA connectors on the cable which carries the audio signal from the computer to the main and subwoofer amplifiers. I was not satisfied with the quality of the connectors, and they were causing an intermittent signal fault with the audio. New gold plated connectors were installed with the aid of a soldering iron and parts holding tool.
Exploded view (left) of the new gold plated connectors with an assembled one on the right.
New RCA connectors installed on the car computer
Finished product with volume knob and screen installed. A very clean installation.
 

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Discussion Starter #18
Consult ECU Reader and Windows 10 Upgrade

Starting off with the windows upgrade, Getting windows 10 to download onto the computer (an upgrade was used, not the free download when it was released) was relatively straightforward and installing the drivers was no more difficult than when it was upgraded to windows 8.1.

By changing a few registry keys some optimizations were made to windows 10. The key points for optimizing windows for the patrol are as follows:
  • Use a local account, not a windows one as all "live" windows accounts require a password to log in each time the PC boots up, which is not ideal for practical use.
  • Change registry key settings so the touch keyboard pops up automatically when a text field is touched in a desktop app (Ie when you tap a text box like you would on an iPhone the keyboard pops up)
  • Setting up tablet mode for ease of use on bumpy roads
  • Changing screen resolution to 720p
  • Changing scaling options to make the windows and text bigger and easier to read

Now for the ECU interface. For anyone reading this who doesn't know, ECU stands for Engine Control Unit. It is a miniature computer that interfaces with my vehicle's engine's electronic fuel pump while simultaneously monitoring a bank of sensors to adjust fuel injection quantity and timing to maintain optimum engine conditions.

The ECU is able to provide real-time output of data such as coolant temperature, turbocharger boost pressure, oil temperature, throttle position ect via a digital output jack and computer interface known as Consult. In addition to providing real-time engine data the ECU also logs any faults and warns the driver by illuminating the orange "check engine" light. Any faults will be saved in the ECU as a code which is also accessible through the Consult interface.

I have been trying to read my Patrol's ECU ever since I bought it and I was not successful for years until I found some scraps of information on a forum that led to me building and prototyping my own ECU interface.

What makes accessing the ECU on the patrol so difficult is that Nissan in its infinite wisdom decided to use their proprietary interface protocols, not with their own 14 pin Consult plug which looks like this:

14 Pin Nissan consult plug
But instead with the much more widely used 16 pin SAE J1962, or more commonly known as OBD2 connector. Using any cheap OBD2 adapter from eBay would result in an error as Nissan consult is not part of the standard protocols that most cheap readers area able to detect.
16 Pin OBDII Connector
In order to build the module I used three components: A Nissan consult reader, an OBD2 cable and an RS232-USB converter. Here are the links to each.
Alternatively this cable might work, and would save a lot of effort in having to adapt the cables.

The ECU reader comes with the 14 pin consult plug, which is useless to me in my vehicle. I used a pinout diagram of the plug similar to this one
Pinout of the consult plug. All of the pins with labels need to be connected to the car
along with a multimeter to trace the wires, I labelled the five important ones with tape and a marker:
Labelling wires from the 14 pin plug
From there I used this pin out for the 16 pin plug which I can verify to be correct, however it is upside down in relation to the orientation of the plug on my car.
OBDII Pinout on my Patrol
The final step was to cut the male end of the OBD2 plug and srip back the wires, then isolate the wires corresponding to the pins in the diagram above and solder them to the interface board plugs. After that I boxed it up and added the USB converter.
Finished Consult Reader

To interface the reader to the car I used a free program called ECUTalk.

I have completed the reader and am about the fit it to the car. I will need to fit a USB extension cable from the car down to the driers side footwell then install the software on the computer.
 

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Discussion Starter #19
Consult Gauges installed and working

Hello and welcome to post #16 of my blog on building an in car computer system. In this post I'll show you how I installed the ECU reader I built in the previous post into my vehicle.

To start off with I removed the plastic driver's side A-pillar cover and ran a 5 Meter USB 2 extension cable from the car computer down to the lower dashboard above the pedals.

From there I cable tied the OBD2 plug and wires in place, then attached the reader in an out of the way position.

ECU reader tucked away inside the dashboard
From there I plugged the USB extension cable into the RS232 converter, then downloaded and installed the driver for the converter.

After that I downloaded ECUTalk onto the computer. From there I found the COM port number (there are several virtual com devices for various accessories) but opening device manager to see a list of connected COM ports, then selected the correct one in ECUTalk.
ECUTalk selection menu
ECUTalk will then automatically connect to the ECU and the parameters able to be monitored with a gauge appear one by one in the menu above. Alarms can also be set in another menu for parameters such as coolant temperature and injector duty cycle.

ECUTalk is almost perfect for my needs, as it is a "one click" solution that automatically displays the gauges after connecting to the ECU.

As mentioned in the previous post, fault codes can also be read and cleared from this program which is really handy.
My gauges on my Patrol
 

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Discussion Starter #20
Switched Power Distribution & Protection System

Due to the large amount of 12V DC accessories and devices of all different shapes and current ratings I have installed in my vehicle, there was a large amount of messy wiring taking up the space where many of the power supply and various signal wires run through the firewall (the only two openings on that side were jammed full of wires!) I decided to design and build a safer, more reliable and easier to fix system.

Messy wiring from the computer & various power circuits.


My solution is the Switched Power Distribution & Protection System, or SPDS for short. It is divided into two modules stacked on top of each other and Its purpose and function is threefold:

1) Provide a high current link directly back to the auxiliary battery for running devices intended for use from that battery. This was done by using industrial grade 1 gauge wire ran directly back to the 100A breaker in my engine bay, which is in turn connected to the battery via a similar cable. The SPDS end runs into a gold plated terminal block (housed in the distribution & protection module) where it splits into different sized wires to power various areas of the vehicle.

1 Gauge battery cable running into the distribution block.
There is also an additional two wires run out of the PD&PM from the terminal blocks and into two high current fuses. these power the four channel and sub-woofer amplifiers.

2) Provide a high-current and reliable platform for improving switching options on the PC. Two issues arose with the original design, which turned the PC on when the key was set to the accessory position in the ignition barrel, and turned it off after a one minute delay when the key was removed.

The first was that it posed a security risk in situations where I wanted to leave the computer on but wanted to lock the car, and was forced to leave the car unlocked as the key had to be in the ignition (EG when I use it for music while working on the car and go inside for a break).

The second was that in situations when I was driving and didn't want the computer to keep automatically turning on (the hard power button kills the computer when held for 3 seconds but it turns on again as its PSU is configured to keep sending an on pulse (the equivalent of someone pressing the power button again) if the key is in the accessory position. The latter function is achieved by simply adding a switch between the accessory wire and PC.

To do this I used three relay switches. The relay labelled illumination is switched by a wire from the park lights. It acts as an isolator between the main and auxiliary batteries so that various devices can be switched on by turning on the park lights without draining the main battery. This is irrelevant for PC functionality however it was installed to run the auxiliary running lights built into my Hella Luminator LED driving lights as it was more convenient to wire them to a relay, switch and then the auxiliary battery then run a power wire across the dash and to a high current park wire and switch.

Relay module
The relay labelled screen (far right) is turned on by a switch in the centre console labelled "Screen Power". it is powered constantly from the distribution module, which turns on when the key is moved to the accessory position. This acts as an isolator between the main and auxiliary batteries so that the turn on signal to the PC (this is a +12V signal which signals the PC to turn on, similar to the remote turn on wires found on automotive amplifiers) can be activated at any time simply by flicking the rocker switch, regardless of key position. If the key is on than this will have no immediate effect.

The relay labelled power is turned on by a wire that is connected to the cigarette lighter socket. It switches on a high current connection from the distribution module to power various devices around the vehicle that only need to be running when the key is in the accessory position, eg extra cigarette lighter plugs.

finally,
3)Put devices and systems on different circuits and protect them with automatic circuit breakers.

These are switches that protect the wiring by automatically opening when a certain amount of sustained current passes through them, eg if a short circuit occurs. These are vital for redundancy as they do not require changing of single use fuses and can be reset on a whim. The configuration of the circuits and their rating is as follows (from the top down):

Distribution & Protection module
1)
Rating: 30A
Area Powered: Overhead Console
Connected Devices:

  • Car Computer
  • Roof Console Lights
Additional Affected Devices & Systems on Failure:
  • Amplifiers will not turn on (Remote turn on signal runs from this circuit).
  • 7 Port USB Hub
  • PC Screen

2)
Rating: 30A
Area Powered: Rear Barn Door
Connected Devices:

  • Rear panel fuse block
Additional Affected Devices & Systems on Failure:


  • Reverse/rear lights
  • Rear cigarette lighter socket (Beware if fridge is connected)
  • Rear USB Charging sockets X2
  • Rear table strip lighting

3)
Rating: 15A
Area Powered: Centre Console
Connected Devices:

  • CB Radio
  • Centre console USB hub Boost power
  • Centre console floor light

4)
Rating: 15A
Area Powered: Unsure
Connected Devices: Unsure

To construct the modules I bought two small project boxes that can be disassembled by hand by pulling off the end plates. I drilled holes in the corners of one side of each box, then fitted metal standoffs and screws to hold them together. As an added bonus the spacing keeps the modules held securely in place in the electronics bay without the need for fasteners.

Fastening the two halves together
I mounted the components in the boxes with stainless steel screws, spring washers & nuts then crimped the wiring together.
Adding components
Connecting components with suitably rated wire
 
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