I am playing around with an Arduino Uno micro controller hoping to display the TPS position on a two digit seven segment LED. It would be easier for me if the Arduino and the TPS had a common supply voltage. How much current can I draw from the WM15M 5v supply to the TPS?

Even though I have fitted a larger LCD display to my Optimiser it is still difficult to know what throttle setting I have, and of course not at all in the dark.

I take your point about pulling the voltage down although I did not think of the starting implications, perhaps I need to have the engine running before starting the Arduino.

I was hoping to directly input the TPS supply voltage and the signal from the potentiometer voltage divider and express it as an 8 bit digital figure, much as you do with the Optimiser, and divide by 16.  Instead I will try to read the signal voltage instead and power the Arduino and LED seperataly.

I am also monitoring the original Magnetti Marellii ecu lambda readings at various settings but of course cannot use the Optimiser for that.  Perhaps I am being a little simplistic assuming I could use the same TPS monitor for both ecu's.

I had not thought

Sorry for the late reply, been busy with work preparing for a two week trip to the Hebrides as an engineer looking after a civilian Islander aircraft supporting the large Joint Warrior military exercise.  Will it ever stop raining up here?

So, I am using the android optimiser but only have an android phone so  also use the laptop as the phone display is a bit small, I have made up a Bluetooth dongle which works ok with the phone.  I have an O2 sensor with the LC1 controller, I have tried running closed loop but not too succesfully yet, seems to rum better open loop at the moment.  I suppose I need more work on the map.  I have become a little distracted perhaps by wanting to know what A/F ratios the standard ecu gives - as a late model bike it may be the map is pretty good.  I may be hung up on the idea that I should first get the MyEcu to perform as well as the oem item, then make the adjustments to improve beyond that.  I feel I need to set the MyEcu to the same A/F  ratios as the oem ecu hence my use of the A/F gauge and the need to know the throttle position. As I understand it, in open loop the ecu supplies the fuel I think it needs with no rerence to the A/F ratio, alternativelly in closed loop it tries to supply the fuel to achieve the a/F ration I have told it to,  well the oem ecu ratios seem a good starting target.

Why am I messing around with the MyEcu? Mainly curiosity with tha ability to control things directly it is a good way of learning about fuel injection in general. I am trying to find out what throttle setting I have when running the oem ecu, it was perhaps a little unfair to ask for your help on this forum.

As an aside, my wife's Susuki Wagon R+ car has the engine management light coming on despite changing the EGR valve and two O2 sensors, all points to the ecu.  Did you get anywhare with the MySusuki idea.

Sorry for the long post, rather boring sitting in this hotelo room.

OK, I will do that on my return home, thanks.