search

PX4 / PX4-Autopilot

PX4 Autopilot Software
https://px4.io
BSD 3-Clause "New" or "Revised" License
8.2k stars 13.37k forks source link

USB serial connection problems with Pixhawk #4230

Closed bkueng closed 8 years ago

bkueng commented 8 years ago

Hi

I have a problem connecting to the pixhawk (fmuv2), via USB cable (using screen /dev/ttyACM0, minicom or QGC, all the same behavior). When I connect the cable, then wait several seconds and try to connect, it succeeds to connect, but I don't get a nsh shell (no reaction when pressing enter, just a blank screen). However when I connect during the first few seconds, right after the big blue led goes on, everything works and I get a nsh shell. When I then exit screen and restart it, it still works. FW uploading also works, but only when I do it within the first few seconds.

I tried with two different boards, both the same behavior. On another computer, they don't have this issue, only on mine, a Thinkpad T440p.

I also tested this with the PixFalcon and it does not have the same problem, it occured only with the pixhawk.

Has anyone experienced similar problems?

LorenzMeier commented 8 years ago

Have you de-installed the modem manager? Have you tried a different USB cable?

bkueng commented 8 years ago

yes & yes

RomanBapst commented 8 years ago

@LorenzMeier It seems strange that it correlates with the time he waits until he connects after boot.

tops4u commented 8 years ago

I have a similar Problem (Mac OS X, AUAV-X2 or Pixracer). When connecting via USB to Pixhawk after it has been powered by Battery very often the connection would not work (with no Error in QGC). Only when disconnecting Battery and USB and restarting only with USB the connction will work. No such Problem when using Serial Telemetry.

LorenzMeier commented 8 years ago

Are you using El Capitan?

tops4u commented 8 years ago

Yes I do. Happend with all Versions of QGC to date (from 2.9 onwards). With PX4 1.2 as well as current master.

LorenzMeier commented 8 years ago

@tops4u Its an issue with El Capitan. Make sure to unplug, close QGC and then only plug back in. That will work around it until Apple fixes it.