Mavproxy failure: [ link 1 down ]

ArduCopter Copter 4.4
1

Hi there.

I would like to connect raspberry pi to speedybee-v3. So I’ve soldered TX6 of FC to GPIO15 ( RPI5 UART RX) and FC’s RX6 to RPI’s GPIO14.

I’ve configured serial0 for RPi:

rpi@rpi: $ pinctrl
…
14: a4 pn | hi // GPIO14 = TXD0
15: a4 pu | hi // GPIO15 = RXD0

I’ve configured UART6 in MissionPlanner:

SERIAL6_BAUD=921
SERIAL6_OPTIONS=160
SERIAL6_PROTOCOL=2

And then I am trying to run mavproxy to check if everything is okay:

rpi: $ mavproxy.py --master=/dev/serial0 --baudrate 921600
WARNING: You should uninstall ModemManager as it conflicts with APM and Pixhawk
Connect /dev/serial0 source_system=255
Log Directory:
Telemetry log: mav.tlog
Waiting for heartbeat from /dev/serial0
MAV> link 1 down

Could you please give me any pointers what could be wrong?

Thanks in advance!

2

Try SERIAL6_OPTIONS=0. You shouldn’t need pullups

3

The same behaviour with SERIAL6_OPTIONS=0.

Could an issue be somehow connected with that I am powering FC from raspberry pi USB port?

How many Mavlink could be used at the same time? I mean that if I am using RPi’s USB port which also using Mavlink ( IIUC ) to communicate with Mission planner, could it be used another one Mavlink at the same time?

4

Ahh, just saw that you’re running a Pi5.

Try using /dev/ttyAMA0 instead. /dev/serial0 is mapped to the small console plug between the HDMI ports.

You may also need to following line in /boot/firmware/config.txt:

dtparam=uart0=on
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5

Thanks, If you /dev/ttyAMA0 everything seems to be working:

mavproxy.py --master=/dev/ttyAMA0 --baudrate 921600
WARNING: You should uninstall ModemManager as it conflicts with APM and Pixhawk
Connect /dev/ttyAMA0 source_system=255
Log Directory:
Telemetry log: mav.tlog
Waiting for heartbeat from /dev/ttyAMA0
MAV> Detected vehicle 1:1 on link 0
online system 1
STABILIZE> Mode STABILIZE
AP: ArduCopter V4.5.4 (fd1bcc61)
AP: ChibiOS: 6a85082c
AP: speedybeef4v3 0024001B 32334717 37333831
AP: RCOut: DS600:1-4 PWM:5-7 PWM:9
AP: Frame: QUAD/X
Received 1102 parameters (ftp)
Saved 1102 parameters to mav.parm

One more question I have and probably you can help me with it. If I want to use Mavlink in halfduplex mode would it be enough just set SERIAL6_OPTION=‘halfduplex’ ( I don’t remember the number )?
And from wiring point of view how it should be connected: FC’s RX to RPI’s TX? Or it doesn’t matter?

6

As far as I’m aware, RPi doesn’t support half-duplex UART. MAVProxy definitely doesn’t

1 Like