Thanks! I saw those files but had no idea what program opened them. Now that I know they are the schematics, I'll go download Target and have a look. I'm doing a similar project for an old motorcycle that I am rebuilding and I think your tach circuit will work better than my original design (which used an opto-coupler between the points and an android pin configured as an interrupt). My plan is to feed all the sensor data into the Arduino and have it send the info to an Android tablet via Bluetooth. I have a dashboard app on the tablet that will display the info as gauges as well as log the data. Thanks again.