Greetings. I have cross-compiled PX4 for the Raspberry Pi 2. The problem is that I cannot get Mavlink output on the serial device.
The Rpi 2’s UART0 (/dev/ttyAMA0) is connected to a PL2303 USB TTL adapter (/dev/ttyUSB0) which is connected to a machine running Ubuntu 15.10.
I am a complete beginner with PX4 and do not own any Pixhawk hardware. My understanding is that after creating a Mavlink stream in PX4 on the UART that I should see junk data on the other side. Instead there is no output. Additionally, ‘mavlink status’ doesn’t indicate that any data is being sent.
pi@navio-rpi ~ $ uname -a
Linux navio-rpi 3.18.9-rt5-v7+ #1 SMP PREEMPT RT Thu Mar 26 10:31:34 UTC 2015 armv7l GNU/Linux
Configuration of /dev/ttyAMA0
pi@navio-rpi ~ $ stty -F /dev/ttyAMA0
speed 57600 baud; line = 0;
min = 1; time = 0;
-brkint -icrnl -imaxbel
-opost
-isig -icanon
Test of /dev/ttyAMA0
Ubuntu Machine
user@ubuntu ~ $ cat < /dev/ttyUSB0
Raspberry Pi 2
pi@navio-rpi ~ $ echo "hi there this is a test" > /dev/ttyAMA0
Ubuntu machine
hi there this is a test
PX4 mainapp running
pi@navio-rpi ~ $ ./mainapp
[init] shell id: 1995
812864
[init] task name: mainapp
______ __ __ ___
| ___ \ \ \ / / / |
| |_/ / \ V / / /| |
| __/ / \ / /_| |
| | / /^\ \ \___ |
\_| \/ \/ |_/
Ready to fly.
pxh>
PX4 starting mavlink
pxh> mavlink start -d /dev/ttyAMA0
WARN mode: 0, data rate: 2880 B/s on /dev/ttyAMA0 @ 57600B
WARN offboard mission init: ERROR
pxh> WARN Disabling hardware flow control
PX4 create HEARTBEAT stream
pxh> mavlink stream -d /dev/ttyAMA0 -s HEARTBEAT -r 1
WARN stream HEARTBEAT on device /dev/ttyAMA0 enabled with rate 1.0 Hz
Ubuntu machine output
user@ubuntu:~$ cat < /dev/ttyUSB0
No output on the serial device.
PX4 mavlink status
pxh> mavlink status
instance #0:
mavlink chan: #0
no telem status.
rates:
tx: 0.000 kB/s
txerr: 0.017 kB/s
rx: 0.000 kB/s
rate mult: 0.050
pxh>