RE: DX8 telemetry RPM pickup for Gas engines - SOLVED!!
Yup that's what I refer to as the Crankcase sensor SPMA9569. Unfortunately, it will not work on gas engines since the carb intake is at the rear of the engine. As for the channels, when you go to the telemetry page there are a number of slots/(channels) and you can go through them and assign various sensors.
I had hooked up the wires as mentioned in other threads, using yellow signal, and black but still did not see readings on the DX8. I did see that everytime the magnet on the shaft went past the sensor, the TM1000 blinked. This, I interpreted as "good sense". I spun the motor up using the electric starter, but despite seeing the TM1000 rapidly flashing got no readings on the DX-8.
At this point I was at wit's end. I had power cycled the Rx numerous times, I did have some concerns with the DX-8 settings in the Telemetry page. Clicking on the first slot where RPM had been assigned, I saw gear ratio, min/max settings for alarms, and poles. I tried changing each with no luck, finally, in desperation I made the first slot EMPTY, and took another slot and assigned it to RPM. Then as a final Genuflection, I put everything in "Bind" mode, and pressing the bind button on the DX8, hit the power. Once everything bound, I again spun the motor with the electric starter. Viola! RPM readings on the iPhone, and on the DX8.
Don't shoot the messager, its the process I went through. Might be I just needed to re-assign the slot. As others go down the path, we might gain better knowledge.
KKKKFL