View Single Post
Old 09-21-2008, 08:16 AM   #6 (permalink)
EcoModding Lurker
Join Date: Aug 2008
Location: Melbourne, Australia
Posts: 7
Thanks: 0
Thanked 0 Times in 0 Posts

Unfortunately the voltage produced by the speedometer output was not sufficient to trigger the transistor. I did some probing and found out that the output was at ground between pulses. I then found a web page that detailed how to use a transistor as a ground triggered switch (Using Transistors As Switches). Using this circuit I have been able to get the MPGuino to read pulses from my speedometer output.

I have done some preliminary calibration and it seems about 2500 pulses/kilometre works well.

Now to get some fuel usage information!

  Reply With Quote