Shark Interface Still Not Working
Apparently, having figured out how the Shark joystick sends its information isn’t quite enough to get it working with the motor driver. I wrote software to send the same information that the joystick would usually send, but didn’t get a response. Then I assumed that the way the data lines both go high before serial signalling commences might have been some sort of init signal, so I have an Arduino configured to send the same information, and I still don’t get a response.
It’s entirely possible that I don’t have the bit timing exactly right for the serial link, so I’m now working on bitbanging the serial in a more adaptable way, so I can test different bit lengths.
I’m going to keep plugging away at it for a bit, but I also have a plan B: lobotomize the motor driver. Assuming it uses an ATMega8 like the controller, I can pull the control IC and replace it with one flashed with the Arduino bootloader, and then use rosserial_arduino to control it from ROS. That does mean I’d want to log what the controller does before pulling it, so I have a rough idea what signals go where, but it would vastly simplify controlling the system.