Automotive Relays Killing GPS & Locking Up Cog
This is a pretty simple setup, Propeller DIP chip, Parallax GPS.
I have the GPS on its own 5v regulator with 1000 uF caps on the 12v side and the output side. The GPS has 2 feet of Cat5 network cable in which the power, ground, and signal wire runs through.
Every time a relay clicks off I get some sort of spike and it kills the GPS. I will get random data like 670 miles per hour, the date and time will turn into hexidecimal characters, etc. Sometimes after 10 seconds or so it will come back to life, and other times the cog will just die until I reboot the board.
So I read about voltage spikes from relays in automobile setups and learned about the diode across the control side of the relay. I pulled a relay and installed this 1000v diode and it fixed the problem for that single relay. In this case the fuel pump relay.
However, I can't tear into the dash and the entire car and ghetto wire diodes into the relays just so the GPS will work. There has to be a better way to fix this problem.
Another guy told me to apply a tiny capacitor as close to the GPS as possible, like a .001 uf. I tried this with no luck. He also suggested wrapping the signal wire close to the Propeller in an RF choke, so I picked up a magnet and did that. Nothing will fix this.
It's lame driving around seeing your speed and direction fine, then you hit the turn signal and everything goes to crap.
Post Edited (SuperCricket) : 10/4/2008 9:25:38 PM GMT