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Writing a Custom UART Driver

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  • LucaVertiqL Offline
    LucaVertiqL Offline
    LucaVertiq
    Contributor
    wrote on last edited by
    #1

    @Moderator Hi, our team is going to be writing a driver for UART control of vertiq motors for PX4 soon. Additionally I'm prototyping with a VOXL 2 Mini and have got the tool chain running. I know the voxl 2 works a bit differently than a standard px4 stm32 board. I was looking at the modalIO and I notice it is enabled in both voxl2-slpi and voxl2 default.px4board files. Is the slpi folder for the DSP half of the chip? Is it just a completely different board that I should ignore?

    Thanks,

    Luca

    ModeratorM 1 Reply Last reply
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    • LucaVertiqL LucaVertiq

      @Moderator Hi, our team is going to be writing a driver for UART control of vertiq motors for PX4 soon. Additionally I'm prototyping with a VOXL 2 Mini and have got the tool chain running. I know the voxl 2 works a bit differently than a standard px4 stm32 board. I was looking at the modalIO and I notice it is enabled in both voxl2-slpi and voxl2 default.px4board files. Is the slpi folder for the DSP half of the chip? Is it just a completely different board that I should ignore?

      Thanks,

      Luca

      ModeratorM Offline
      ModeratorM Offline
      Moderator
      ModalAI Team
      wrote on last edited by
      #2

      @LucaVertiq you will need your uart driver to run in the slpi portion of the build. you should be able to find everything you need here: https://docs.modalai.com/voxl-px4/

      LucaVertiqL 1 Reply Last reply
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      • ModeratorM Moderator

        @LucaVertiq you will need your uart driver to run in the slpi portion of the build. you should be able to find everything you need here: https://docs.modalai.com/voxl-px4/

        LucaVertiqL Offline
        LucaVertiqL Offline
        LucaVertiq
        Contributor
        wrote on last edited by
        #3

        @Moderator Thanks, that's where I've been looking. I'll have to look harder at the slpi portion of the build to understand it better. If I have more questions I'll be back. Thanks!

        Eric KatzfeyE 1 Reply Last reply
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        • LucaVertiqL LucaVertiq

          @Moderator Thanks, that's where I've been looking. I'll have to look harder at the slpi portion of the build to understand it better. If I have more questions I'll be back. Thanks!

          Eric KatzfeyE Offline
          Eric KatzfeyE Offline
          Eric Katzfey
          ModalAI Team
          wrote on last edited by
          #4

          @LucaVertiq Yes, you have a choice of where to put the driver depending on what UART port you are planning to use. If you use a UART available to the applications processor then you would use the standard voxl2 build. If you use a DSP UART then you would use the voxl2-slpi build.

          LucaVertiqL 1 Reply Last reply
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          • Eric KatzfeyE Eric Katzfey

            @LucaVertiq Yes, you have a choice of where to put the driver depending on what UART port you are planning to use. If you use a UART available to the applications processor then you would use the standard voxl2 build. If you use a DSP UART then you would use the voxl2-slpi build.

            LucaVertiqL Offline
            LucaVertiqL Offline
            LucaVertiq
            Contributor
            wrote on last edited by
            #5

            @Eric-Katzfey Ahh that makes sense. I see in the voxl 2 mini datasheet that it says apps or slpi proc for each uart. That's great.

            So on the slpi proc how do I know what uart number to use in PX4. It looks like in the spektrum driver is selects uart 7 and the modal_io driver selects uart 2 which seems to match QUP7 and QUP2 in the datasheet:
            01cd2787-0445-4c8e-a7eb-37eafca4cfcc-image.png

            Am I understanding that correctly so far?

            Eric KatzfeyE 1 Reply Last reply
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            • LucaVertiqL LucaVertiq

              @Eric-Katzfey Ahh that makes sense. I see in the voxl 2 mini datasheet that it says apps or slpi proc for each uart. That's great.

              So on the slpi proc how do I know what uart number to use in PX4. It looks like in the spektrum driver is selects uart 7 and the modal_io driver selects uart 2 which seems to match QUP7 and QUP2 in the datasheet:
              01cd2787-0445-4c8e-a7eb-37eafca4cfcc-image.png

              Am I understanding that correctly so far?

              Eric KatzfeyE Offline
              Eric KatzfeyE Offline
              Eric Katzfey
              ModalAI Team
              wrote on last edited by
              #6

              @LucaVertiq Yep, that is correct.

              LucaVertiqL 1 Reply Last reply
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              • Eric KatzfeyE Eric Katzfey

                @LucaVertiq Yep, that is correct.

                LucaVertiqL Offline
                LucaVertiqL Offline
                LucaVertiq
                Contributor
                wrote on last edited by
                #7

                @Eric-Katzfey Thanks to you we now have our motors running right off the SLPI processor with PX4 as a UART 'bus'. Everything seems to work great. The main issue was figuring out what qshell commands to send to start it up properly.

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