206 2.0 HDI Accelerator sensor question

[praxibetel]

Hi all,

I have an '04 206 HDI with an accelerator position sensor at the pedal (my previous 206 had a throttle cable running to a sensor attached to the airbox). I've been thinking about making a cruise control system using an Arduino microcontroller hooked into the OBD port and intercepting the accelerator signal.

What kind of signal should I expect from this sensor? Is it just PWM, an analogue voltage, or something more involved? Also, as far as I know, models without cruise control don't have a clutch switch, but I should be able to fit an OEM one?

If anyone more experienced than myself has any comments on the whole idea, I'd like to hear them!
Thanks in advance and happy new year!

[spider]

Interesting idea.

From memory its just an analogue voltage, there are likely two one decreasing and one increasing (as a fail safe) , I'm unsure you will be able to get a 'quick' reading though as to read the TPS you'd have to have the ECU 'open' all the time. I know it can be done in some ways as you can take the PP on the road and read it (well, a passenger can read it while the driver drives)

You should have a suitable hole on the clutch pedal for a switch already in most cases. You may have a switch fitted here, have a look. Note the switch on the brake pedal (assuming your car is RHD) if fitted is *not* the brake light switch, that's on the passenger side.

Not sure what to add to this. Have you looked into factory cruise ? , pretty sure it must of been available on some of the models, even if not UK spec...

[praxibetel]

I had a poke around and my car does indeed have a clutch switch already. And yup it's RHD, so the brake switch is indeed on the passenger side. Do you reckon I won't be able to read speed/rpm data fast enough for real time adjustment of the accelerator? Reading the throttle position should be no problem if it's just one or two analogue signals, then I can have the arduino send a suitable signal down to the ECU.

The most I've done with OBD is reading a few fault codes, and using Torque on my phone to display a boost gauge for my amusement. I might look on ebay for a cheap accelerator sensor on ebay to play with reading and replicating the signal.

I had a bit of a dig online about retrofitting factory cruise and apparently it's quite a lot of trouble. Plus I could also add things like automatic rev matching while braking if I can detect where the gearstick is (reed switches + magnets maybe?)

[Northern_Mike]

Isn't it just a case of buying the cruise stalk, plugging it into the comm2000 unit and setting it up with Lexia/Peugeot Planet? That's all it took on my Berlingo, same year, same engine and the C5 I fitted it too. Took all of 10 mins.

[praxibetel]

Really? I read somewhere on the internet (I know, a reliable source) that it would require a bunch of extra wiring through the firewall to the ECU and stuff. In any case having an Arduino in the car hooked up to the OBD would open up a word of interesting possibilities.