First Prize

Fuel-Consumption Gauge for Your GM Car

This low-cost project measures fuel consumption in real time. An ATmega8515 microcontroller collects vehicle speed and airflow data from the vehicle’s engine computer using the SAE J1850 VPW bit-serial bus, which is one of the on-board diagnostic buses required by the OBD-II standard. A modified off-the-shelf electronic tachometer is used as an analog display to show the consumption rate in miles per gallon. Only a few extra components are necessary for this efficient project, including transistors, diodes, resistors, and capacitors. Special automotive bus interface chips are unnecessary.

Bruce Lightner

U.S.

lightner@lightner.net

Abstract | Entry

Winners List