Please Help,
i have a pixhawk 2.1 and after try to firmware upgrade, the pixhawk only blink red and there is no reaction in /dev/ttyACM0
i use qgc and have no idea.
Any ideas?
What firmware did you flash? And can you try to upgrade again in QGC?
Blinking red usually means it is in bootloader mode because there is no firmware flashed.
The German Log is a problem for you?
QGroundControl kann die Firmware auf Pixhawk Geräten, SiK Radios und PX4 Flow Smart Kameras aktualisieren.
Alle QGroundControl Verbindungen zu Fahrzeugen müssen disconnected prior to firmware upgrade.
Please unplug your Pixhawk and/or Radio from USB.
Plug in your device via USB to start firmware upgrade.
Gerät gefunden: PX4 FMU V2
Verbunden mit Bootloader:
Version: 5
Board ID: 255
Flash Grösse: 2080768
Firmware wird heruntergeladen…
Von: http://px4-travis.s3.amazonaws.com/Firmware/stable/px4fmu-v3_default.px4
Herunterladen abgeschlossen
MAV_AUTOPILOT = 12
Erfolgreich entpackt parameter_xml
Erfolgreich entpackt airframe_xml
Erfolgreich entpackt image
Erasing previous program…
Erase complete
Programming new version…
Error: Brennen fehlgeschlagen: Befehl fehlgeschlagen: 0X13 (PROTO_INVALID) bei Adresse 0x00000000
Verbesserungen abgebrochen
Deutsch passt auch 
Ok, so the flashing fails, that’s odd. Can you try to flash px4fmu-v2_default? I suppose you can’t actually choose, so that doesn’t work… 
.
And which QGC version are you using?
Thank you,
How can i read this info?
I have also the possibility for Mission Planner.
But there i have weniger experience.
Mission Planner V1.3.64
And it doesn’t work with Mission Planner and neither QGroundControl?
I try it with MP and QGC. No success.
Can i give you some more infos?
The speed of flashing with qgc is to fast for my thinking.
The Mission Planner works.
I have upload the firmware for ardupilot, i think. Like the painless 360 descript.
QGC has the same problem like before, no reaction.
I beleave i have installed the Chibios and ardupilot.
The behavior from qgc while calibration looks strange then used to be with PX4.
The error like above is the same after trying new firmware upload.
Now is installed:
Arduplane V3.9.7
ChibiOS
fmu v3
.
And now i find the following discussion:
Mission Planner works for firmware, but QGC does not.
Is there a idea for beginners?
My guess here is that Hex is using a new bootloader which is not yet recognised by QGC in a stable build. See https://github.com/mavlink/qgroundcontrol/pull/7319
A daily build of QGC should work.