Arduino ...

[BertieWells]

So I do quite a lot with arduino at University, for those of you who dont know it is a programable micro controller. I was thinking changeable colour and brightness dash lights (Just made my own blue ones out of the bulb holders and some leds i had lieing around). Its pretty small so this could all be hidden behind the dash easily. What else would you guys want? Bearing in mind the range of things this could handle is pretty bloody large
I would imagine most things that could be bought on the market could be made/copied with arduino at a lower cost but would depend on what it is. If you guys have some good ideas id most likely be happy to guineapig it and get it working on my van then if you want one i don't see why i couldnt make some for you if you are happy to cover parts and postage

Just shout some ideas and ill have a think if its possible. Basically anything that isnt as simple as just a switch being operated (although that is simple enough to do with arduino)

• Variable LED Colour/Brightness Dash Lights (Brightness could be manual or based on actual light levels, colour could be manual or possibly controlled by revs or speed)
  Engine Bay Lights switched on and off via a switch and or the bay being opened and closed
  Bleeping/flashing parking sensors
  GPS logger to show where you have been (Possible digital speedo)
  Infinitly variable windscreen wiper speeds
  A VW spotting counter (press a button to add a counter of how many t25s youve seen)
  Tacometer
  Thermometer (Internal and External)
  etc

Regards

Rob

[CJH]

(Possible digital speedo)

...maybe combined with a digital tacho and engine runtime meter (and a clock, obviously)? The combined tacho/engine runtime meters I've looked at get bad reviews for being slow to respond to changes in revs - better suited to lawnmowers that run at constant revs.

[BertieWells]

So essentually you would want a display that shows
Speed
Revs
Time
Speed and time are dirt simple and could be done completely seperate to the mechanics of the van. WIll need to look into how the dash recieves informaition on engine speed but it shouldnt be too difficult to tap into ... in theory

[CJH]

Bertie - it's only a suggestion. I've been looking for a digital tacho that could fit in the space above the steering column cowl where the heated seats switch would go, but haven't been able to find anything. See this thread.

One problem is that many of the dashboards that don't already have a tacho are the early type, for which there isn't a suitable signal behind the dash. I think it'll need a wire running from the coil - my best guess about this is in that thread, but I'm sure others know better. I don't really know what sort of signal you would monitor on that coil wire.

My dash is so early that it doesn't even have a clock either.

My thought about the engine runtime counter was that it might be useful to record running time (e.g. a clock that accumulates whenever the revs are non-zero) for the purposes of oil changes, service intervals etc, although most will prefer to do this on mileage/time anyway.

So not a universal 'must have', but it's something I'd be interested in at least.

[BertieWells]

Me too, I have Speedo, Engine Temp and Fuel. Minimalistic

I love the cowling to go on the top of the steering coloumn with the display. Could potentially show anything on there or mod it to have a full display. Any idea where you can get themfrom? I had a quick look but no joy.

I wonder if like in some vehicles the bottom range models have all the wiring for the top range models just with blanking plates put in where switches would go. I wonder if its the same/similar in the case. Although if its to do with the age of the vehicle then possibly not?

Well if you could get a tachometer reading then you could do what ever you like with it LEDs, Motors, Servos. You could use it to control what ever you like. If i can figure out how to get a tachometer reading somehow ill knock something together for you to test

Rob

[CJH]

Any idea where you can get themfrom? I had a quick look but no joy.

Hi Rob - the cowl is part number 251 953 515 A. Brickewerks sell them here. I bought mine from a trader at a show earlier in the year, but the switch hole is still empty!

[BertieWells]

Awesome, thanks!

[BertieWells]

Just been looking, to see when a spark plug is fired you can wrap a coil of wire around it to get an induced current (so simple) my question is this....
Is one revolution of the engine done by each spark plug fireing once?

[Aidan]

the petrol spark system is distributor type with single plug per cylinder but it is 4 stroke cycle remember

the tacho and dynamic oil pressure system in the later vans takes the signal from the coil as it collapses/generates spark
on the diesel the signal form is different and comes from the w terminal on the alternator

[BertieWells]

Ahhh i see but i dont think i explained my self very well. It would be possible to calculate the speed of the engine if you knew either the time between a spark plug fireing and then fireing again or possibly a little more accurate would be to see how many times it fires over a period of time. But what one would need to know is,is 1 revolution of the engine completed by each spark plug firing once or perhaps do you get two revolutions for each spark plug firing etc etc

[CJH]

Hi Rob

The spark fires on every other revolution, so if you're counting sparks in one cylinder you need to multiply by two to get rpm. I think if you take the signal from the coil, I suppose you'd get a pulse for each spark plug, so with a four cylinder engine you'd have four times as many pulses, and you'd therefore count the pulses and divide by two. Someone will correct me I'm sure.

I have no idea what factor you'd apply to the signal from the w terminal on the alternator in the case of a diesel.

[BertieWells]

Yes that is perfect being able to half the value is going to make it more accurate as well. I think ill concentrate on the petrol first as thats the engine ive got. It would be a nightmare developing the code for the diesel not being able to test reguraly. Although if i talked someone through it im sure i could keep sending them updates for the code. Got a lot of uni work on at the moment but definitly going to get a tachometer working

[what2do]

I'm in! What do you need from us? Stamps, envelopes, tea bags, encouragement, you name it!!!

[Ian and Lins]

No idea if I'm right but; couldn't you get an induced signal of the HT lead from the coil to the distributor? And then would this be 1 signal per revolution of the crank?

[BertieWells]

Where would you guys want this mounted? The cowling above the steering colomn seems like a good shout to me because i think i could potentially build it as one plug and play unit. All you guys would have to do, assuming this works is find a 12v supply and run the wire to the back how ever you please.