Hello, I'm currently trying to build a self-balancing robot with the arduimu as the brains of the operation driving a vex motor. To make pid tuning easier, I've been trying to get the ArduIMU to read data over serial. However, it appears Serial.read() is always returning -1 and Serial.available() never goes above 0. Any ideas why?
ArduIMU uses a custom FastSerial library. I thought that was causing the problem, but I've since removed all calls for FastSerial (which is basically everything having to do with the GPS) and I still cannot read any serial input on the ArduIMU. Any luck on your end with this problem? (I know I'm about a year too late.)
Sorry, I abandoned my efforts to try and communicate with the ArduIMU over serial. I'd crack it open again to see if I could get it working a year later, but it's still stuck at school along with the rest of my stuff.
I figured it out! The ArduIMU V3 already receives serial data from the GPS connection. For some reason, the GPS uses the TX line of the AVR, then another random pin that is used for the RX line. The Serial port that the code is referring to is the GPS RX pin. There's a setting in the code that changes a Serial_Mux pin to select between the normal hardware RX pin and another pin on the board. There are two options: