Bespoke digital dash for T25

[ed_crouch]

Hi all.

I want a rev counter for my bus. I'm well pi**ed off with the idea of spending 100 notes for a dodgy used one off a watercooled bus with a water temp gauge that I wont use.


Soooooo, I bought a microprocessor (ATmega 2560 for interested geeks like me) development board and a backlit LCD, and have been coding away. My digital dash module will have a circular LED bar graph rev counter, an RPM readout on the LCD, oil pressure, oil temperature, fuel %age, and possibly engine bay air temperature. Things like gearbox (auto) oil temperature and any other temperature or pressure you can think of could be included.

I need to make a tee piece to fit the pressure sender in the crankcase, machine a billet ally dipstick cover plate to replace the steel one to fit the temperature sender in, and machine up an aluminium insert to fit it all into the right hand pod in the dash. The ally insert will be anodised black. OK, so it'll cost me more than the used rev counter would have, but it will be spot on and, open/scaleable/adaptable. It'll have the added benefit that the fuel gauge will be calibrate-able, so it will be accurate (grief above!!), and a simple digital filter in the software will remove the old gauge sway when you corner.

I'll keep the thread updated as and when I do more work on it, and in the spirit of Arduino (the dev't board I'm using), I will give the code to anybody who wants it (with no guarantees expressed or implied; this is experimental work) and the drawings for the machined parts.

There are many options out there for LCD displays, and it can display more or less whatever parameters you can imagine, subject to being able to fit the van with the relevant sensor. The Mega2560 microprocessor will even drive a colour TFT screen happily, but lets not get too far away from the 1980's kitsch style, eh... Perhaps I could code up a Westy check splash screen?

Any interest or am i out here on my own?!?

[ninja.turtle007]

I don't need one as I have aa Scangauge but what you are doing sounds really good.

[ed_crouch]

interesting! I hadnt heard of scangauge - I guess it relies entirely on an EOBD connex in the van though? It makes sense to as otherwise you end up duplicating sensors.

[scottbott]

cannot understand what you are talking about,might as well be greek,but a digital dash would be good,will keep my eyes on to this post

[CovKid]

Sounds good to me.

[nobbyfox]

So will it look like the interior of KITT? (Knight Rider to all the younger ones out there)
Might look too modern in an 80's van

[tonytech]

Sounds great.
love the idea of extra sensors to monitor the beast at the back (I dont mean my daughter)
I've played with ATMEGAs, Arduinos, toyed with the digital dash, but as my original works perfectly gave up.
Now I'm off coding for Raspberry pi.

T

[syncroandy]

Ed, sounds interesting, you're not alone ! I've seen recently that quite a few folk are making custom digital instrumentation based on Arduino boards and similar, combined with cheap LCD displays. Seems to be quite an affordable and accessible way to display specific engine data in a compact space, compared with (eg) two or three VDO gauges.

I chose a different route for the main instrumentation. I'd already upgraded the engine to a late-90's TDI, and I opted for the dash panel from the donor car a 3B Passat. The advantages of this are that its fairly thin (compared with many) and can just be fitted into the available space, and is quite 'hackable', in that the odometer can be reset, and other adjustments made by modifying the EPROM. It is also readily available and quite cheap, typically £30 on Ebay.

I'm currently working on an adapter kit, using water-jet/laser cut components, to permit people to relatively easily fit these into the T3. Coming back to the Arduino, I'm considering an option for my kit, to have a 8x2 LCD at each side of the Passat dash panel, to display additional data, probably oil temp/pressure, and maybe EGT. I use a Scangauge as well, which can display any ECU parameter. The Passat dash panel has the MFA, which displays:

External air temp
Journey elapsed time
Journey trip distance
Journey average speed
Journey avergare MPG
Instant MPG

The MPG data is only available if you have a modern ECU, but my intention is to make the kit work with older petrols/diesels and Subaru engines. This depends on designing an interface board to convert the speedo/tacho signals, which is still in the very early design stages.

[nobbyfox]

Syncroandy, Will your components (hopefully) fit within the original dash or will it have to be wildly adapted?

[lloydy]

Andy, that looks better every time i see a picture of it ( need a smiley thats represents me drooling over it!)

[syncroandy]

Nobby, no the dashboard itself is unmodified for fitting the Passat dash panel. My initial version required a slight clearance to be made (with an angle grinder) but I thought better of this and made some rebates in my mounting bracket instead, to avoid hacking the dashboard.

There is however a modification to accommodate moving the light switches. There are various ways to do this, but I chose to use a Golf 3 switch fitted in the air vent hole, which meant I had to create a new hole to relocate the air vent. If Golf 1 lighting switches were used instead, it might be possible to fit these in somewhere without moving the air vent, but they would still need new holes cut.

Lloyd, thanks ! I got the first 'production' batch from the water jet cutters today, plus the first batch of polycarbonate covers. The cover works pretty well, with less reflection then I feared. It sits concave, like the original, which changes the appearance of reflections and makes them less obvious. Final job on the first batch is to get them powder-coated in a textured dark grey or black. My prototype was just flat rattle-can black, and it looks a bit amateurish. I think it's worth spending the extra few quid to get a more professional finish on the metal.

Next big chunk of work is to design and produce the interface board. This isn't really required, but will make it a far more plug and play solution, and allow me to integrate some signal conversion electronics. As it stands now, external 'black boxes' such as the Dakota Digital are required, anyone wanting to be an early adopter will have to use those as it'll take me a while to do the interface board.

[zzippyman]

Andy, can I just say that looks terrific? Well it does! I'm drooling here too

[icosahedron]

Didn't mean to take this thread off topic. Having done something similar I am most interested in this project.

[syncroandy]

That's seriously impressive. Is this type of work your trade or are you just an incredibly talented enthusiast ?

Might need to pick your brains about choices for board schematic/layout software..

E D I T: If people are wondering, the seriously impressive bit of work by Icosohedron was removed, for reasons that aren't clear, as it seemed pretty much on-topic to me..

[CovKid]

Thread has somewhat drifted....