Raspberry Pi 4B and Pixhawk 6C connected via USB-A (on the Pi) to the USB-C connection on the Pixhawk. Running mavproxy on the RPi. The RPi receives power from a DC-DC converter that converts pack voltage (50V) to 5v, and, the Pixhawk receives power from the same source (i.e. Pixhawk power in and RPi power in both powered from the DC-DC converter).
Connecting with:
mavproxy.py --state-basedir=$MAVPROXYLOGDIR --logfile=$MAVLOG --append-log --non-interactive --master=/dev/$PORT --baudrate=921600 --out=tcpin:0.0.0.0:14550 --out=tcpin:0.0.
0.0:14551 --out=tcpin:0.0.0.0:14552 --out=tcpin:0.0.0.0:14553 --out=udp:127.0.0.1:14558 --default-modules=arm,mode
We generally run mavproxy 24 hours a day. It is generally stable for hours at a time, but, occasionally, perhaps every 4-12 hours, I get a Link 1 Down error. It always recovers in a few seconds, i.e., it prints this to stdout:
@stephendade and others, do you have any suggestions as to where to look for the root cause of this? We checked:
- Lowering baud rates doesn’t eliminate this (in fact I don’t think it affects this at all)
- This happens when the rover is sitting stock still, so we do not suspect a loose wire.
- The autopilot is not out of memory, nor is it out of disk space (dataflash log space) nor is its load ever reported to be > 10%.
- The RPi isn’t reporting errors in the system log (dmesg, etc.).
- There are other usb devices on the RPi (intel realsense, and a usb connected LTE modem); we could try disconnecting them to see if this problem goes away.
the “no link” message comes when mavproxy hasn’t received data over the serial port for some period of time, so we are focusing on instrumenting the serial port /dev/ttyACM0 activity.
Any thoughts as to what to try or where to look would be much appreciated!
Thank you!