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  4. Connect the VOXL 2 I/O using the UART port on the 5G modem

Connect the VOXL 2 I/O using the UART port on the 5G modem

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  • Alex KushleyevA Alex Kushleyev

    Regarding the RTK corrections not working while GPS is connected to the DSP, I am assuming you have an RTK service that downloads the data from internet and sends a mavlink message with the corrections. That mavlink message needs to be consumed by the gps driver and rtk corrections forwarded to the GPS receiver via UART. If this is not happening, then perhaps the mavlink message never gets to the GPS driver inside the DSP, potentially being filtered out somewhere (mavlink manager?). I don't have deep enough knowledge there, maybe others can comment.

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    SMRazaRizvi
    Regular
    wrote on last edited by
    #19

    @Alex-Kushleyev But the RTK corrections come in when I connect the RTK to the 5G modem over J9. What do you think makes a difference here?

    Alex KushleyevA 1 Reply Last reply
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    • S SMRazaRizvi

      @Alex-Kushleyev But the RTK corrections come in when I connect the RTK to the 5G modem over J9. What do you think makes a difference here?

      Alex KushleyevA Offline
      Alex KushleyevA Offline
      Alex Kushleyev
      ModalAI Team
      wrote on last edited by
      #20

      @SMRazaRizvi When you connect the GPS to J9, you start the GPS driver on the cpu side, so there is probably nothing that filters out the mavlink messages with corrections between the rtk mavlink service and your gps driver.

      When starting GPS driver on the DSP, there may be a filter somewhere that prevents the rtk corrections mavlink message from reaching the DSP.

      That is my guess

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      • Alex KushleyevA Alex Kushleyev

        @SMRazaRizvi When you connect the GPS to J9, you start the GPS driver on the cpu side, so there is probably nothing that filters out the mavlink messages with corrections between the rtk mavlink service and your gps driver.

        When starting GPS driver on the DSP, there may be a filter somewhere that prevents the rtk corrections mavlink message from reaching the DSP.

        That is my guess

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        SMRazaRizvi
        Regular
        wrote on last edited by
        #21

        @Alex-Kushleyev I see.
        I'll try to splice the connection for GND, SDA, and SCL and connect them to the J19 on VOXL2.

        In this case, should the GND, SDA, and SCL pins be connected to both the J9 on the 5G modem and the J19, or just to the J19?

        Alex KushleyevA 1 Reply Last reply
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        • S SMRazaRizvi

          @Alex-Kushleyev I see.
          I'll try to splice the connection for GND, SDA, and SCL and connect them to the J19 on VOXL2.

          In this case, should the GND, SDA, and SCL pins be connected to both the J9 on the 5G modem and the J19, or just to the J19?

          Alex KushleyevA Offline
          Alex KushleyevA Offline
          Alex Kushleyev
          ModalAI Team
          wrote on last edited by
          #22

          @SMRazaRizvi just J19 for gnd, sda and scl.

          Then you still have gnd, 3.3V, rx, tx going to GPS.

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          • Alex KushleyevA Alex Kushleyev

            @SMRazaRizvi just J19 for gnd, sda and scl.

            Then you still have gnd, 3.3V, rx, tx going to GPS.

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            SMRazaRizvi
            Regular
            wrote on last edited by
            #23

            @Alex-Kushleyev Works like a magic!!
            Thank you so much 🙂

            Alex KushleyevA 1 Reply Last reply
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            • S SMRazaRizvi

              @Alex-Kushleyev Works like a magic!!
              Thank you so much 🙂

              Alex KushleyevA Offline
              Alex KushleyevA Offline
              Alex Kushleyev
              ModalAI Team
              wrote on last edited by
              #24

              @SMRazaRizvi awesome..

              I want to look into why running the GPS driver on the DSP did not result in RTK corrections getting through.. This would simplify your setup.

              Can you please help me by telling me the topic name that is published by the RTK (rtcm) publishing app? I think it is just not going through to the DSP (being filtered out) for some reason. Also, just curious what app are you using to publish the mavlink messages with RTK (rtcm) corrections?

              Alex

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              • Alex KushleyevA Alex Kushleyev

                @SMRazaRizvi awesome..

                I want to look into why running the GPS driver on the DSP did not result in RTK corrections getting through.. This would simplify your setup.

                Can you please help me by telling me the topic name that is published by the RTK (rtcm) publishing app? I think it is just not going through to the DSP (being filtered out) for some reason. Also, just curious what app are you using to publish the mavlink messages with RTK (rtcm) corrections?

                Alex

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                SMRazaRizvi
                Regular
                wrote on last edited by
                #25

                @Alex-Kushleyev Sure.

                But currently, I've crashed my drone after it suddenly flipped 180 roll, and crashed on the ground while I was flying.

                For some Here's the log:

                Link Preview Image
                Flight Review

                favicon

                (review.px4.io)

                Can you see what's the issue here?

                Alex KushleyevA 1 Reply Last reply
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                • S SMRazaRizvi

                  @Alex-Kushleyev Sure.

                  But currently, I've crashed my drone after it suddenly flipped 180 roll, and crashed on the ground while I was flying.

                  For some Here's the log:

                  Link Preview Image
                  Flight Review

                  favicon

                  (review.px4.io)

                  Can you see what's the issue here?

                  Alex KushleyevA Offline
                  Alex KushleyevA Offline
                  Alex Kushleyev
                  ModalAI Team
                  wrote on last edited by
                  #26

                  @SMRazaRizvi ,

                  I took a quick look, at the very end it looks like motor 2 (green) was commanded zero output

                  2303060f-0b32-4e8a-84a1-16c06389ebeb-image.png

                  If the PWM range on VOXL2_IO is not calibrated properly, if the mixer is outputting zero, it could result in VOXL2_IO commanding low enough PWM to motor that can cause it to stop.

                  Can you please let me know if your motors are spinning right after you arm the vehicle (but before you raise the thrust), or they spin up only after you arm AND then raise the throttle stick?

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                  • Alex KushleyevA Alex Kushleyev

                    @SMRazaRizvi ,

                    I took a quick look, at the very end it looks like motor 2 (green) was commanded zero output

                    2303060f-0b32-4e8a-84a1-16c06389ebeb-image.png

                    If the PWM range on VOXL2_IO is not calibrated properly, if the mixer is outputting zero, it could result in VOXL2_IO commanding low enough PWM to motor that can cause it to stop.

                    Can you please let me know if your motors are spinning right after you arm the vehicle (but before you raise the thrust), or they spin up only after you arm AND then raise the throttle stick?

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                    SMRazaRizvi
                    Regular
                    wrote on last edited by
                    #27

                    @Alex-Kushleyev The motors were all working fine since the start. I flew the drone for a while actually and then it suddenly crashed.

                    Alex KushleyevA 1 Reply Last reply
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                    • S SMRazaRizvi

                      @Alex-Kushleyev The motors were all working fine since the start. I flew the drone for a while actually and then it suddenly crashed.

                      Alex KushleyevA Offline
                      Alex KushleyevA Offline
                      Alex Kushleyev
                      ModalAI Team
                      wrote on last edited by
                      #28

                      @SMRazaRizvi , As I mentioned in my previous post, the plot shows that for some reason there was a command for Motor 2 to go to zero (which would convert to the minimum PWM value of 1000). Do you remember if you have performed some aggressive maneuver at the end, which would trigger this?

                      Also, can you please perform acuator test using GCS and figure out at which actuator output value, your motors actually spin up?

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                      • Eric KatzfeyE Eric Katzfey

                        @SMRazaRizvi We have not integrated an RTK GPS receiver before so cannot comment on the steps needed to get it working properly. Perhaps the manufacturer of the RTK GPS unit can provide some guidance on how to use it with PX4? Or the PX4 community? But if you are seeing valid data from the unit then at least the hardware seems to be connected properly.

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                        valvarez
                        Contributor
                        wrote on last edited by valvarez
                        #29

                        @Eric-Katzfey In my case I am receiving data as @Alex-Kushleyev explains with

                        stty -F /dev/ttyHS2 115200
                        cat /dev/ttyHS2
                        

                        e1b7860f-60b8-4441-a7f9-c4147a44b66c-image.png

                        and in the script in /usr/bin/voxl-px4-start I see that section @Eric-Katzfey
                        6bd3d8f4-b89b-4fa6-ad40-5c58260d333b-image.png

                        but when it comes to running voxl-px4 it autodetects with different bauds to the GPS. Is it necessary to change it somewhere else?
                        e7941c5d-6d4b-4a0c-b5ab-a9e4130ef09b-image.png

                        I have no problems with the MAG. It detects it perfectly.
                        I have the RX and TX of the GPS connected exclusively to the J9 of the 5G, and the rest, to the J19.

                        I also have the RX and TX of the IO Board connected to the RX and TX of the J19.
                        I have also tried disconnecting the IO Board and leaving only the GPS on the J9.

                        SOLVED: I change in the file voxl-px4-start from M0052 to M0054. Thanks!!!

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