I have been thinking about building a car pc. It would replace the whole instrument cluster and display the speedometer and other instruments on a small 7"-10” TFT screen. It would use a small pico-ITX motherboard with a small SSD drive or CF-card and a Linux operating system.

I`m pretty sure I can figure out the programming and software by myself but the hardware is a problem.

I need some sort of device to connect all the sensors to the computer. Can anyone give me a tip if there`s something usable already on the market?

Something like this?

http://www.fusioncontrolcentre.com/FusionStore//catalog/product_info.php?cPath=25&products_id=62&osCsid=d306de6bdf1e04d4d3fbfd943012fcee

I looked at this quite seriously a year or two ago and the big problem I had was finding a screen visible in daylight that didn't cost more than the car.
Maybe things have moved on ?

You'd have to deply recess the screen to avoid glare I guess, otherwise an OLED display would be good but still expensive for anything bigget than a phone screen.

To interface the sensors, if you can do programming etc how about an Arduino or Pic based circuit with A2D inputs for all gauges? Have a Google search as there's quite a lot of stuff around about LCD guages to borrow from. The circuit would interface by Serial or USB to the car pc.

[Edited on 12/3/10 by GRRR]

Ive been thinking the same, but havent really looked into it.

How cool would it be to have a gauge display the same as a 500k supercar!!?!

You could do some pretty trick things with screensavers and sleep mode as well.

The outputs from MS should be fairly easy to work out, so its just a matter finding the right hardware and programming the software.
I was originally thinking about something like Trend software (the same that operates plant in buildings!) but if theres a more specific system then that would work better. It needs to auto boot within a few seconds as well, or youd get bored waiting for it!

Did a lot of similar stuff to my dashboard. There's a touchscreen LCD showing info from various sensors and the ECU, and I've got 2 Koso LCD gauges for everything else.

I often wish I'd gone for plain old needle dials though because at least I'd be able to see them in bright sunlight.

If you do go ahead with it, don't forget to add some kind of backlight dimming for night driving.

Ed.

doesnt the lcd display that plugs into the power commander do all that?

I would lik this too, and unplug it as an anti theft devise.

I have seen these in the states in home built lanes.

Jus had a thought.

Could you not use the scene from a laptop/DVD and have a separate processor?

A backlit LCD screen is definitely better than LED - I can hardly see my blue LED Evodash in bright sunlight (brilliant at night though)

A lappy screen would be enormous in a car IMO - even one of the tiny netbooks would be too big. Maybe a Satnav screen could be adapted?

[Edited on 12-3-10 by RazMan]

quote:

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Originally posted by RazMan
A backlit LCD screen is definitely better than LED - I can hardly see my blue LED Evodash in bright sunlight (brilliant at night though)

A lappy screen would be enormous in a car IMO - even one of the tiny netbooks would be too big. Maybe a Satnav screen could be adapted?

[Edited on 12-3-10 by RazMan]

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Here's my dashboard system.



It's a self designed PCB and code was written using the Swordfish compiler for PIC18F8722. There's a SD card slot for data logging and it reads OBD data from Ford ECU, speed, tacho, 2 x temperatures etc and calculates MPG, 0-60 times and all that sort of stuff. I did have a 3 axis G sensor connected at one point but vibration killed it.

A bit more info here, and some bigger pics.
Link

Ed.

The tft screens above 3.5" require a lcd controller so the screen can be updated at a rate of 30-60 times a second.
Below this size most have a controller.
Also these tft screens do require a ffc connector (normally 0.5mm pitch) so you do need a pcb to be made up.

Darren

I was toying with the idea of using a Nokia N810 tablet as my display, and use a wifi or bluetooth link to a mini PC behind the dash which did the hardware interfacing. The advantage of the N810 is that it has a screen designed to be visible in direct sunlight, and it does a respectable 800x480 resolution

The easiest screens to use are the 7" DVD screens that hang on the back of the headrest to keep your kids quiet. I think most (all?) come with a standard video connector that can be connected to a suitable equipped PC.

They appear to have some options on here

carcomputer , link goes to a monitor, but they seem to do some other interesting gear too.

[Edited on 12/3/10 by Toltec]

[Edited on 12/3/10 by Toltec]

For the screen I have been thinking about using something like this:

http://www.cartft.com/catalog/il/1158
(or some other model in the catalog)

Sun light shouldn`t be an issue if the screen is located in a recess just like most car`s instruments.

For the interface card I found this:
http://www.velleman.eu/distributor/products/view/?country=be&lang=en&id=351346
(they have also some other models). It gets power from usb directly.

For the mother board this would probably work well: http://www.via.com.tw/en/initiatives/spearhead/pico-itx/

Though slightly larger mini itx or nano itx board would be cheaper.

I built my own dash a while back and has day/sunlight problems.

First error was blue seven segment's for speed.
Now are highbrightness red ones.

The Rev counter and fuel guage are LED circular bar graphs.
They still need better LED's.

Everything else is on a cheap 2 row text LCD transrefective module.
Works well in bright sunlight but still could be better.

As for colour Graphic displays, they are not generally any good in sun light.

I think the current option is the Transreflective types are the ones to go for, only problem is price (mega).


If I was to make another DIY dash my first thing would be to test each display option outside on a sunny day.

Look at the forums at mp3car.com

I have an 8 inch touchscreen in my work car for gps/music and obd2 engine diags. Bright sunlight is a pain though. I have thought of recessing it in the console of the senesq though.
Dale