I got an ArduPilot Mega from SparkFun which seems to have a common problem with the firmware not being loaded correctly. The inputs could not be read and when changing to manual mode, the output and MUX light would twitch very rapidly.
After getting a BusPirate, I flashed the ATMega328 with what I believe are the correct fuse settings (DFFF & FE), using the provided .bat file.
The board is now working consistently when I connect it via USB (using the 5V IMU board or with the 3.3V FTDI Basic Breakout). I would like to power it with the standard setup I have in my glow powered model plane, which has a 6V battery, but the PPM encoder does not seems to work when the board is powered by a 6V battery. I am powering it via the receiver, not directly.
When powered with the 6V battery, the PPM light stays on (does not blink) and the MUX light is also always on (does not read the input from IN7). I've measured the voltage in the board on both scenarios:
- Powered by USB: Output reads 4.99V
- Powered by Battery: Output reads 6.55V
I would consider feeding the received with a voltage regulated input, but the ArduPilot Mega manual states that it can be powered from a 7V to 14V source (http://code.google.com/p/ardupilot-mega/wiki/Hardware), which leads me to believe that something is not working correctly (maybe the internal voltage regulator).
Does anyone have any suggestion on how I can troubleshoot this problem?