Hexacopter 1.param (18.0 KB)
Connected to Pixhawk 6C. After the Pixhawk boots (all the little beeps) the motor plays its twin-tone “ready for arming” then the motor “stutters”, that is it briefly and intermittently rotates a fraction of a turn even before the safety switch has been pressed. After a while of that both the motor and ESC are warm, not even close to too hot to touch, but noticeably warm. When I run the motor test the stuttering stops, but the motor does not spin at all. BLHeli_S ESCs (Photo 1)
Connected to the FMU PWM output. Motors assigned to channels 9-14 (hexacopter). Loop rate set to 400, MOT_PWM_TYP set to 6 (Dshot600). Have tried multiple speed settings. Have looked at the channel’s output on an oscilloscope. Pre-arm, to me looks fine. According the specs I found (here) , each pulse is fine and the overall frame is at least close (scope hasn’t been calibrated in years…). Decided maybe it is still a configuration issue and built a tester out of an Arduino. I sends pre-am (all zeroes) for 2 seconds, then a value 48 for 5 seconds, then ramps up to a value of 1046, which according to the document I found is supposed to be 50% motor speed. Signal is 5V pulses. This photo
shows the first few bits of the 1046 value (100000… Can’t time the last pulse showing at this scale, but it’s a 1) at a scale you can time the pulse widths. Yeah, there is some voltage overshoot, but it is an Arduino, I have no idea what capacitance is on that pin. This
shows the entire pulse train in a scale you can easily decode the bits. According to my interpretation, it is indeed 1046 with checksum as described in the document. This
is the same thing at a scale to measure the frame length which comes out to really close to the Dshot600 frame time. Motor still doesn’t spin. Reflashed the firmware using BLHeli configurator in case a previous configuration “confused” the ESC. NO CHANGE.
What the BLEEP am I missing here?
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