Skip to content
  • Categories
  • Recent
  • Tags
  • Popular
  • Users
  • Groups
Collapse
Brand Logo

ModalAI Forum

  1. ModalAI Support Forum
  2. VOXL Compute & Autopilot
  3. VOXL 2
  4. VOXL2 with IO board, Graupner RC, F9 uBlox GPS, and the FPV ESC 4-in-1

VOXL2 with IO board, Graupner RC, F9 uBlox GPS, and the FPV ESC 4-in-1

Scheduled Pinned Locked Moved VOXL 2
9 Posts 3 Posters 1.4k Views 1 Watching
  • Oldest to Newest
  • Newest to Oldest
  • Most Votes
Reply
  • Reply as topic
Log in to reply
This topic has been deleted. Only users with topic management privileges can see it.
  • R Offline
    R Offline
    restore
    Regular
    wrote on last edited by
    #1

    I am hoping to get some guidance on initial setup for a custom drone using VOXL2. Our GPS (uBlox ZED-F9P) isn't being published.

    px4-listener sensor_gps
    never published
    

    GPS is set to autodetect

    I tried forcing gps start with 115200 and 38400 (from manual) but get the same command failed result.

    px4-qshell gps status returns

    INFO  [qshell] Send cmd: 'gps status'
    INFO  [qshell] qshell return value timestamp: 482903338, local time: 482904782
    

    we tried the following but the command failed

    px4-qshell gps start -b 38400
    INFO  [qshell] Send cmd: 'gps start'
    INFO  [qshell] cmd returned with: -1
    INFO  [qshell] qshell return value timestamp: 487577618, local time: 487581068
    ERROR [qshell] Command failed
    

    QGC recognizes that the GPS_1_PROTOCOL = u-blox

    Dan JenningsD 1 Reply Last reply
    0
    • R restore

      I am hoping to get some guidance on initial setup for a custom drone using VOXL2. Our GPS (uBlox ZED-F9P) isn't being published.

      px4-listener sensor_gps
      never published
      

      GPS is set to autodetect

      I tried forcing gps start with 115200 and 38400 (from manual) but get the same command failed result.

      px4-qshell gps status returns

      INFO  [qshell] Send cmd: 'gps status'
      INFO  [qshell] qshell return value timestamp: 482903338, local time: 482904782
      

      we tried the following but the command failed

      px4-qshell gps start -b 38400
      INFO  [qshell] Send cmd: 'gps start'
      INFO  [qshell] cmd returned with: -1
      INFO  [qshell] qshell return value timestamp: 487577618, local time: 487581068
      ERROR [qshell] Command failed
      

      QGC recognizes that the GPS_1_PROTOCOL = u-blox

      Dan JenningsD Offline
      Dan JenningsD Offline
      Dan Jennings
      Contributor
      wrote on last edited by
      #2

      To add a bit more info;

      ESC is connected to VOXL2 J18 and J4
      VOXLIO is connected to VOXL2 J19 pins 9-12

      Doodle Labs Dev port is connected to 5G carrier board J12
      mRo Zed F9p is connected to 5G carrier board J9

      If this is just a configuration issue where we need to point voxl or px4 to a different port I'd love to learn how.

      Alex KushleyevA 1 Reply Last reply
      0
      • Dan JenningsD Dan Jennings

        To add a bit more info;

        ESC is connected to VOXL2 J18 and J4
        VOXLIO is connected to VOXL2 J19 pins 9-12

        Doodle Labs Dev port is connected to 5G carrier board J12
        mRo Zed F9p is connected to 5G carrier board J9

        If this is just a configuration issue where we need to point voxl or px4 to a different port I'd love to learn how.

        Alex KushleyevA Offline
        Alex KushleyevA Offline
        Alex Kushleyev
        ModalAI Team
        wrote on last edited by Alex Kushleyev
        #3

        @Dan-Jennings and @restore ,

        if you run commands using px4-qshell, the commands are sent to the DSP. However, since you have connected your GPS to 5G carrier board J9, that uart is mapped to the CPU (Application Processor) : https://docs.modalai.com/voxl2-linux-user-guide/#devttyhs2---hsb2b-connector-uart

        On VOXL2, some parts of PX4 run on DSP and some run on the CPU. Sometimes, components can run in either place, depending on the application (for example, the GPS driver)

        So you should start your gps driver without qshell and use /dev/ttyHS2 as the device name.

        px4-gps start -d /dev/ttyHS2
        

        Please try that

        Alex

        R 1 Reply Last reply
        0
        • Alex KushleyevA Alex Kushleyev

          @Dan-Jennings and @restore ,

          if you run commands using px4-qshell, the commands are sent to the DSP. However, since you have connected your GPS to 5G carrier board J9, that uart is mapped to the CPU (Application Processor) : https://docs.modalai.com/voxl2-linux-user-guide/#devttyhs2---hsb2b-connector-uart

          On VOXL2, some parts of PX4 run on DSP and some run on the CPU. Sometimes, components can run in either place, depending on the application (for example, the GPS driver)

          So you should start your gps driver without qshell and use /dev/ttyHS2 as the device name.

          px4-gps start -d /dev/ttyHS2
          

          Please try that

          Alex

          R Offline
          R Offline
          restore
          Regular
          wrote on last edited by
          #4

          @Alex-Kushleyev thank you very much for you help. That did the trick and the GPS is working now

          Alex KushleyevA 1 Reply Last reply
          0
          • R restore

            @Alex-Kushleyev thank you very much for you help. That did the trick and the GPS is working now

            Alex KushleyevA Offline
            Alex KushleyevA Offline
            Alex Kushleyev
            ModalAI Team
            wrote on last edited by
            #5

            @restore , Excellent! you are welcome.

            R 1 Reply Last reply
            0
            • Alex KushleyevA Alex Kushleyev

              @restore , Excellent! you are welcome.

              R Offline
              R Offline
              restore
              Regular
              wrote on last edited by
              #6

              @Alex-Kushleyev if we use the mRo GPS u-Blox Neo-M9N – IST8308 in order to have a compass (but still plugged into the 5G board) how do we start the ist8308 on dev/ttyHS2?

              Alex KushleyevA 1 Reply Last reply
              0
              • R restore

                @Alex-Kushleyev if we use the mRo GPS u-Blox Neo-M9N – IST8308 in order to have a compass (but still plugged into the 5G board) how do we start the ist8308 on dev/ttyHS2?

                Alex KushleyevA Offline
                Alex KushleyevA Offline
                Alex Kushleyev
                ModalAI Team
                wrote on last edited by
                #7

                @restore , /dev/ttyHS2 is a UART only port that is mapped to the CPU. If you use a compass on the same connector of the carrier board J9, that i2c will also be mapped to CPU. However, we currently do not support compass driver running on the CPU side.

                A workaround could be to wire the I2C connectors (and gnd) to another i2c port, which is connected to the DSP. I am going to paste my response related to a very similar question from another user:

                compass driver is started inside the voxl-px4 start-up script : /usr/bin/voxl-px4-start

                # Auto detect the magnetometer. If one or both of these devices
                # are not connected it will fail but not cause any harm.
                /bin/echo "Looking for qmc5883l magnetometer"
                qshell qmc5883l start -R 10 -X -b 1
                /bin/echo "Looking for ist8310 magnetometer"
                qshell ist8310 start -R 10 -X -b 1
                

                please note that both of these drivers are expecting the compass to be connected to the DSP i2c ports. We currently don't have compass driver that can run on the cpu side (unlike GPS). However, you could potentially splice the connection for GND, SDA, SCL and connect the i2c bus to J19 on VOXL2, so that you can use the DSP driver for the compass.. Is that an option for you?

                R 1 Reply Last reply
                0
                • Alex KushleyevA Alex Kushleyev

                  @restore , /dev/ttyHS2 is a UART only port that is mapped to the CPU. If you use a compass on the same connector of the carrier board J9, that i2c will also be mapped to CPU. However, we currently do not support compass driver running on the CPU side.

                  A workaround could be to wire the I2C connectors (and gnd) to another i2c port, which is connected to the DSP. I am going to paste my response related to a very similar question from another user:

                  compass driver is started inside the voxl-px4 start-up script : /usr/bin/voxl-px4-start

                  # Auto detect the magnetometer. If one or both of these devices
                  # are not connected it will fail but not cause any harm.
                  /bin/echo "Looking for qmc5883l magnetometer"
                  qshell qmc5883l start -R 10 -X -b 1
                  /bin/echo "Looking for ist8310 magnetometer"
                  qshell ist8310 start -R 10 -X -b 1
                  

                  please note that both of these drivers are expecting the compass to be connected to the DSP i2c ports. We currently don't have compass driver that can run on the cpu side (unlike GPS). However, you could potentially splice the connection for GND, SDA, SCL and connect the i2c bus to J19 on VOXL2, so that you can use the DSP driver for the compass.. Is that an option for you?

                  R Offline
                  R Offline
                  restore
                  Regular
                  wrote on last edited by
                  #8

                  @Alex-Kushleyev

                  We have a few different GPS chips here so I went ahead and removed the Zed F9P GPS and plugged the M8N into the J19 connector as shown in the Voxl2 Offboard sensors documentation. I reverted the gps port and baud changes we had previously made in /usr/bin/voxl-px4-start and verified that the magnetometer lines that you provided were already there.

                  We now have GPS working off the M8N, but no compass still (checking with PX4-listener)

                  Running journalctl -b -u voxl-px4 the applicable area looks like this:

                  Apr 16 23:24:58 m0054 voxl-px4[1848]: Looking for ist8310 magnetometer
                  Apr 16 23:24:58 m0054 voxl-px4[1848]: INFO  [qshell] Send cmd: 'ist8310 start -R 10 -X -b 1'
                  Apr 16 23:24:58 m0054 voxl-px4[1848]: INFO  [qshell] cmd returned with: -1
                  Apr 16 23:24:58 m0054 voxl-px4[1848]: INFO  [qshell] qshell return value timestamp: 12785145, local time: 12786961
                  Apr 16 23:24:58 m0054 voxl-px4[1848]: ERROR [qshell] Command failed
                  Apr 16 23:24:58 m0054 voxl-px4[1848]: INFO  [qshell] Send cmd: 'gps start'
                  Apr 16 23:24:58 m0054 voxl-px4[1848]: INFO  [qshell] qshell return value timestamp: 12834740, local time: 12835521
                  

                  offboard sensors
                  https://docs.modalai.com/voxl2-guides-onboard-offboard-sensors/

                  M8N
                  https://store.mrobotics.io/mRo-GPS-u-Blox-Neo-M8N-Dual-Compass-LIS3MDL-IST831-p/m10034-li8303.htm

                  R 1 Reply Last reply
                  0
                  • R restore

                    @Alex-Kushleyev

                    We have a few different GPS chips here so I went ahead and removed the Zed F9P GPS and plugged the M8N into the J19 connector as shown in the Voxl2 Offboard sensors documentation. I reverted the gps port and baud changes we had previously made in /usr/bin/voxl-px4-start and verified that the magnetometer lines that you provided were already there.

                    We now have GPS working off the M8N, but no compass still (checking with PX4-listener)

                    Running journalctl -b -u voxl-px4 the applicable area looks like this:

                    Apr 16 23:24:58 m0054 voxl-px4[1848]: Looking for ist8310 magnetometer
                    Apr 16 23:24:58 m0054 voxl-px4[1848]: INFO  [qshell] Send cmd: 'ist8310 start -R 10 -X -b 1'
                    Apr 16 23:24:58 m0054 voxl-px4[1848]: INFO  [qshell] cmd returned with: -1
                    Apr 16 23:24:58 m0054 voxl-px4[1848]: INFO  [qshell] qshell return value timestamp: 12785145, local time: 12786961
                    Apr 16 23:24:58 m0054 voxl-px4[1848]: ERROR [qshell] Command failed
                    Apr 16 23:24:58 m0054 voxl-px4[1848]: INFO  [qshell] Send cmd: 'gps start'
                    Apr 16 23:24:58 m0054 voxl-px4[1848]: INFO  [qshell] qshell return value timestamp: 12834740, local time: 12835521
                    

                    offboard sensors
                    https://docs.modalai.com/voxl2-guides-onboard-offboard-sensors/

                    M8N
                    https://store.mrobotics.io/mRo-GPS-u-Blox-Neo-M8N-Dual-Compass-LIS3MDL-IST831-p/m10034-li8303.htm

                    R Offline
                    R Offline
                    restore
                    Regular
                    wrote on last edited by
                    #9

                    @restore After reading older posts, changing the Voxl start script to add the ist8308 magnetometer to the build instead of the ist8310 solved the issue. I can now see the compass through PX4-listener

                    1 Reply Last reply
                    0

                    Hello! It looks like you're interested in this conversation, but you don't have an account yet.

                    Getting fed up of having to scroll through the same posts each visit? When you register for an account, you'll always come back to exactly where you were before, and choose to be notified of new replies (either via email, or push notification). You'll also be able to save bookmarks and upvote posts to show your appreciation to other community members.

                    With your input, this post could be even better 💗

                    Register Login
                    Reply
                    • Reply as topic
                    Log in to reply
                    • Oldest to Newest
                    • Newest to Oldest
                    • Most Votes


                    ModalAI
                    Categories Recent Tags ModalAI.com Docs
                    © 2026 ModalAI® · Accelerating autonomy for smaller, smarter, safer drones · Powered by NodeBB
                    • Login

                    • Don't have an account? Register

                    • Login or register to search.
                    • First post
                      Last post
                    0
                    • Categories
                    • Recent
                    • Tags
                    • Popular
                    • Users
                    • Groups