I am currently trying to set up a new mixer for an underwater ROV using px4 and a pixhawk. But I do only get PWM output on four channels when using this mixer:
M: 3
O: 10000 10000 0 -10000 10000
S: 0 0 -6000 -6000 0 -10000 10000
S: 0 1 6000 6000 0 -10000 10000
S: 0 4 4000 4000 0 -10000 10000
M: 3
O: 10000 10000 0 -10000 10000
S: 0 0 -6000 -6000 0 -10000 10000
S: 0 1 -6000 -6000 0 -10000 10000
S: 0 4 -4000 -4000 0 -10000 10000
M: 3
O: 10000 10000 0 -10000 10000
S: 0 0 6000 6000 0 -10000 10000
S: 0 1 6000 6000 0 -10000 10000
S: 0 4 -4000 -4000 0 -10000 10000
M: 3
O: 10000 10000 0 -10000 10000
S: 0 0 6000 6000 0 -10000 10000
S: 0 1 -6000 -6000 0 -10000 10000
S: 0 4 4000 4000 0 -10000 10000
M: 2
O: 10000 10000 0 -10000 10000
S: 0 2 9000 9000 0 -10000 10000
S: 0 3 5000 5000 0 -10000 10000
M: 2
O: 10000 10000 0 -10000 10000
S: 0 2 9000 9000 0 -10000 10000
S: 0 3 -5000 -5000 0 -10000 10000
Loading this mixer on /dev/pwm_output0 only makes motor 1-4 controllable, and the pwm info command gives the following output:
device: /dev/pwm_output0
channel 1: 1500 us (alternative rate: 400 Hz failsafe: 1500, disarmed: 1500 us, min: 1100 us, max: 1900 us, trim: 0.00)
channel 2: 1500 us (alternative rate: 400 Hz failsafe: 1500, disarmed: 1500 us, min: 1100 us, max: 1900 us, trim: 0.00)
channel 3: 1500 us (alternative rate: 400 Hz failsafe: 1500, disarmed: 1500 us, min: 1100 us, max: 1900 us, trim: 0.00)
channel 4: 1500 us (alternative rate: 400 Hz failsafe: 1500, disarmed: 1500 us, min: 1100 us, max: 1900 us, trim: 0.00)
channel 5: 0 us (alternative rate: 400 Hz failsafe: 0, disarmed: 1500 us, min: 1100 us, max: 1900 us, trim: 0.00)
channel 6: 0 us (alternative rate: 400 Hz failsafe: 0, disarmed: 1500 us, min: 1100 us, max: 1900 us, trim: 0.00)
channel 7: 0 us (alternative rate: 400 Hz failsafe: 0, disarmed: 1500 us, min: 1100 us, max: 1900 us, trim: 0.00)
channel 8: 0 us (alternative rate: 400 Hz failsafe: 0, disarmed: 1500 us, min: 1100 us, max: 1900 us, trim: 0.00)
channel group 0: channels 1 2
channel group 1: channels 5 6 7 8
channel group 2: channels 3 4
The four first channels is configured exactly as expected, but I can not get it to configure all channels. and it is only the first four channels that are controllable by sending messages to to control_group_0.
I have also tried the IO_pass mixer. Using this I can control 6 motors (and not 8 as I would expect).
Is there something in the mixer configuration that I am missing? Or is this a bug?