Pymavlink Send_RC issue

[EliotBR (Eliot)]

Hi @Neve,

@Neve

I use the pymavlink to send the depth channel with the pwm value of 1800. And the video shows that the thrusters spin at a very low speed, definitely not the speed corresponding to the value of 1800.

@EliotBR

The effect of the specified value(s) will depend on the flight mode, joystick/pilot input gain, and potentially also the RC3_* parameters if you’ve changed them.

It may be helpful to refer to this gist that I made last year as an example of a full pymavlink program, that hopefully makes understanding the setup and control a bit easier/more intuitive. I unfortunately haven’t yet had a chance to transfer those components to our documentation examples.

Adding to that, the example linked to there includes some code that checks what the vehicle is outputting on each thruster, which can help you determine if it’s a settings/parameters issue or something hardware based (e.g. low power, damaged thruster, etc).

Note also the various failsafes that are built in. MAVLink connections expect to receive a heartbeat message at least every second (if not received the communication may be stopped), and when you’re controlling the vehicle it’s subject to the heartbeat failsafe, and rc override commands are subject to the pilot input failsafe and to RC_OVERRIDE_TIME.

@Neve

I also tried to upgrade the pixhawk and install the new version Raspberry Pi, but it changed nothing. What should I do now?

Your screenshot of the Companion web interface is showing version 0.0.17, whereas the latest version is 0.0.31. There have been some changes to how mavproxy is set up between those versions, so it would likely be helpful if you can update or do a fresh install.