I thought I'd sex up my new 3DR Hex with some LED strips. I connected a JDrones IO board to a Y cable coming off the telemetry port of the APM and after hooking it up as per this diagram it seems to be working as expected.
However, when it's connected and I power everything up my 3DR radio tx doesn't work. If I unplug the JDrones IO board and power everything up the radio works fine and I can then connect the JDrones IO board and it works as well.
Has anyone else had this issue? What's the secret to getting the JDrones IO board and the 3DR radio to work at the same time?
Replies
You have a conflict if you have both the TX lines connected. You need to either have the IO-Board talking (TX connected to APM RX) or the 3DR Radio talking to the APM, if you have both there is a conflict. They probably just send an init message to the APM at the same time at power up, and it gets garbage to process.
It the same situation when you use MinimOSD board.
J-Drones diagram is wrong. For serial you can only have one to one mapping for transmitting. The trick is you can have more than one listener.