PMW3901 Optical Flow Sensor

Ardupilot Quick Start Guide

To enable the Holybro PMW3901 optical flow sensor in Ardupilot, set FLOW_TYPE to 4 and SERIALx_PROTOCOL to 18.

If you are not sure which serial port you are using, here is a list of serial mapping for the Pixhawk 6 family:
SERIAL1 -> UART7 (Telem1)
SERIAL2 -> UART5 (Telem2)
SERIAL3 -> USART1 (GPS1)
SERIAL4 -> UART8 (GPS2)
SERIAL5 -> USART2 (Telem3) (not included on 6C Mini)
Once the sensor is correctly configured, check the opt related values from the status tab. If the values are non-zero while moving the sensor around, you are good to go.

Optical Flow Sensor Testing and Setup Copter documentation

PX4 Quick Start Guide

To enable the Holybro PMW3901 optical flow sensor in PX4, simply set SENS_EN_PMW3901 to enable, and the SENS_TFLOW_CFG to the corresponding port that sensor is connected to.
To save the settings, reboot or power cycle the flight controller.


Once the sensor is correctly configured, you can head to MAVLink Inspector->OPTICAL_FLOW_RAD section to check the sensor reading to make sure the sensor is operational.

Optical Flow | PX4 Guide (main)