How to connect ESC's through FMU-PWM-out port (Pixhawk 4)

PX4 Autopilot Flight Controllers 💻
1

I’m building a quadcopter using the PX4 kit and I accidentally dropped a tiny bit of hot solder in the I/O-PMW-in port of the Pixhawk 4 Power Module (PM07) board (http://www.holybro.com/manual/PM07-Quick-Start-Guide.pdf). Although I tried cleaning it as best as I could, I believe this is causing a connection problem with the ESC’s which are connected using M1-M4. The PX4 is connected to the PDB through the I/O PWM OUT <-> I/O-PMW-in connection.

I was wondering if I could program the PX4 to send the signals to the motors using the FMU PWM OUT <-> FMU-PWM-in connection, and have the ESC’s connected to the FMU-PWM-out ports on the PDB.

Here are the pinouts for the PX4: http://www.holybro.com/manual/Pixhawk4-Pinouts.pdf

Thanks in advance for any assistance you can provide!

2

Connect your cable from I/O PWM OUT to the PDB’s FMU-PWM-in, or use the 8 pin remote rail. Pins 1-8 on on the PDB FMU-PWM-OUT or remote will be MAIN 1-8, since you are really running them on I/O PWM OUT. Power is still supplied through the pads, but the ESC’s are PWM controlled through MAIN 1-8

If you want to use something on the FMU-PWM-OUT, you can use the remote rail on it as well. I believe these would be AUX 1-8.

The documentation for how the FMU and I/O connections relate to the PDB are not really clear. The PDB’s FMU-PWM-in is really a FMU or I/O in, and the FMU-PWM-OUT is really a straight through connection to that port.