Replies

  • Larry M November 26, 2015 at 7:29am
    I finally got my GPS working. It turned out to be a power supply issue, nothing to do with BBB. I can't say why this fix works, but I noticed that when the BBB is powered off of my 5v wall power supply or Lipo battery, the GPS did not work, while powered off of the USB power, it does. My wall supply isn't very precise and outputs 5.25V. My battery goes through an APM power module (from Hobbyking) and provides 5.5v, which gets knocked down to 5.2 after the Schottky diode I put in series. The USB puts out 5.0v. So I put together my own L7805cv voltage regulator to independently power the GPS, and viola, it works! The regulator outputs a steady 5.0v. I've checked several times to verify the problem reappears when power it the old way.

    I can't understand why this would make any difference. I have a cheap GPS compass unit so am not surprised it isn't robust. The receiver is a NEO M8M powered by a 3.3v regulator inside the unit, so shouldn't care if the externally applied voltage is 5.0 or 5.2v. But it does. Anyway, as long as the BBB is working, I'm happy.

    So my BBBMINI quadcopter is now all ready to fly... Wish me luck!
    • Developer
      Linus > Larry M November 30, 2015 at 12:15am

      Great to hear that Larry!

      It somehow sounds like my Neo7 GPS that does not want to play with one of my BBBmini's.

      I will try to see if it is a similar thing again now :)

  • Larry M November 22, 2015 at 11:14am

    Hi all,

    I've been (slowly) modifying my 3D printed quadcopter over to BBB.  I'll upload pictures soon.  However, I need some troubleshooting tips.

    Everything's about ready to go.  Gyro, barometer, compass, RC controller all work, and I can connect to Mission Planner through MavLink.  Haven't tested the motors yet...  I am currently stuck on the GPS and desperately need help!

    I have a UBLOX NEO-M8N (actually, one of these units: GPS link).  It works great with my APM 2.6.  When I connect it to the BBBMINI PCB, I get gpsstatus = 1 so I know the BBB is talking to the GPS just fine, but satcount stays at zero, and I get GPS: No Fix.  It does this outside with clear skies.  I've tried switching back and forth to the APM 2.6.  With my APM, it works, with the BBB, doesn't work.  There is also an led on the GPS that seems to indicate when it has a lock.  Solid = no lock, and blinking = lock.  Connected to the APM, it blinks to indicate it has lock, but with the BBB it stays solid, so no lock.  I should also add that I also updated the UBLOX configuration file based on the instructions here, but it didn't help.  Still works with APM, but not with BBB.

    Has anyone else struggled with this?  Any tips on how I can troubleshoot? 

    • Mirko Denecke > Larry M November 22, 2015 at 1:53pm

      Hi Larry,

      start with enable debug messages from the ardupilot ublox driver https://github.com/diydrones/ardupilot/blob/master/libraries/AP_GPS... .

      Best regards

      Mirko

    • Larry M > Mirko Denecke November 22, 2015 at 2:15pm

      Great suggestion.  So I understand I want to set:  #define UBLOX_DEBUGGING 1

      Dumb question...  it looks like the debugging code is sending the output via a "hal.console->printf".  Where does that send the text?  To the command line?  I have the code autostarting at BBB boot-up, so will probably need to kill it and restart.

      Also, my compass is giving me headaches now.  EKF is complaining "Error Compass Variance" and "Bad AHRS", and heading is drifting all over the place.  It was working!  Still works when I plug in the APM, so something about this darned BBB setup is not liking my GPS or compass.  Maybe I need to try a different GPS/compass.

    • Larry M > Larry M November 22, 2015 at 2:19pm

      Nevermind about the compass problem!  I had forgotten to reconnect the I2C port, so it was grabbing the compass measurement from the MPU9250.  I haven't calibrated that yet.

      That GPS, on the other hand, is still a problem...

    • Admin
      Thomas J Coyle III > Larry M November 22, 2015 at 12:43pm

      @Larry M,

      I had to use a Sparkfun  3v/5v level shifter with my 3DR LEA-6 GPS to get it to work with the BBBMINI.

      Regards,

      TCIII AVD

    • Larry M > Thomas J Coyle III November 22, 2015 at 2:09pm

      Thanks Thomas.  Before connecting, I verified (or at least I thought I verified) that the GPS compass serial outputs were already at 3.3V.  I couldn't find a schematic of my unit, but assumed it has a regulator in there to step the 5 volts down to 3.3. Maybe I better go back and check those voltages...

      Also, I have a sneaking suspicion that the GPS compass is finicky about its power supply.  That has been a key difference in how I've been testing at home.  When I switch over to the APM, the GPS compass is powered off of the USB port on the APM, but on the BBB it gets its power off the 5V power supply from the wall.  However, I just switched the BBB over to battery power, and the GPS still isn't working.  Power supply is at 5.2 volts, which should be good enough for the GPS. 

  • Thomas Rotskas November 8, 2015 at 9:47am

    Hi Mirko,

    I used your layout and ordered some PCBs.

    First I need to say, this is a really cool design and it fits completly my needs.

    Everything seems to work fine, but the RC-Input is delayed by several seconds.

    Some times it takes up to 5 seconds, from lowering the throttle, to response of the motors.

    I'm using FrSky SBUS and also tried PPSUM, both react exactly the same(Software is the latest ArduCopter Rev V3.4-dev 2ffabe9e) .

    I'm searching now for 2 days....

    ...does anybody have an idea, what I doing wrong? 

    Best Regards

    Thomas

    • Mirko Denecke > Thomas Rotskas November 8, 2015 at 9:56am

      Hi Thomas,

      I switched to FrSky S-BUS X8R a few weeks ago. I had also delay issues with some X8Rs. I could solve this with upgrading the X8R Firmware, because the latest revision fix a S.BUS bug. But PPSUM should work fine. Do you have connected the RX GND to the BBBMINI GND?

      Best reagrds

      Mirko

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