Arm/Disarm doesn't work properly

Blue Robotics Software
1

For hardware I use a raspberry pi 4b, a pixhawk 4 and two 4 in 1 ESCs. I can reach the web interface but when i try to test the motors and arm the esc nothing happens and i cant turn the motors. When ich hold the slider slighty over or under 1500 the motors beep and calibrate to that level. When i let go of the slider the motors turn at 0%. I think the arming does not work properly. I have tried multiple blueos versions and multiple pixhawk firmware. I also tried on dshot and on pwm

2

Hi @konrad, welcome to the forum :slight_smile:

It’s hard for us to provide advice on products that we aren’t familiar with, especially if you don’t even mention which product you’re using (otherwise we could at least try to check a datasheet).

Assuming you’re using ArduSub, are these bidirectional ESCs? If they’re intended for quadcopters/planes then they may be single-directional, in which case the ESC-arming pulse duration is 1100µs instead, and they won’t work with ArduSub unless you can flash them with a bidirectional firmware.

Note that there are two levels of arming:

  1. The autopilot firmware arming functionality determines whether or not the flight controller board (Pixhawk 4 in this case) outputs any non-neutral PWM signals to its motors
  2. ESCs have their own arming conditions, where they usually need to receive a consistent, valid neutral signal for some time before they allow the motors they’re controlling to rotate

If your ESCs aren’t completing their arming sequence with a 1500µs pulse-duration signal then either they’re not bidirectional, or there’s a slight mismatch in the signals they’re measuring that you may need to fix by configuring a PWM trim on the relevant servo outputs.

3

Sorry i forgot the ESCs and thank you for the fast response. They are both HAKRC 8B45A. With BLHeliSuite I flashed both to be bidirectional and accept the PWM signals as said in the documentation (min 1100, 0% 1500 and max 1900)