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  4. Installing VOXL IO on Sentinel Drone – QUP2 and QUP7 Conflicts

Installing VOXL IO on Sentinel Drone – QUP2 and QUP7 Conflicts

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  • T Offline
    T Offline
    tonygurney
    Contributor
    wrote on last edited by
    #1

    Hello ModalAI Team,

    I was wondering if you have a specific guide or documentation on how to install the VOXL IO on the Sentinel drone. I’ve run into a couple of issues regarding available QUP ports:

    The QUP2 port (J18) is currently occupied by the ESC.

    The QUP7 (J16) port has its RX line already in use by the receiver for my remote controller. Pin 11 is already being used.

    Given this setup, am I expected to remove the ESC and rewire the motors to the VOXL IO? Or is there an alternate recommended configuration for integrating the VOXL IO on the Sentinel platform?

    Any guidance or examples you could provide would be greatly appreciated.

    Eric KatzfeyE 1 Reply Last reply
    0
    • T tonygurney

      Hello ModalAI Team,

      I was wondering if you have a specific guide or documentation on how to install the VOXL IO on the Sentinel drone. I’ve run into a couple of issues regarding available QUP ports:

      The QUP2 port (J18) is currently occupied by the ESC.

      The QUP7 (J16) port has its RX line already in use by the receiver for my remote controller. Pin 11 is already being used.

      Given this setup, am I expected to remove the ESC and rewire the motors to the VOXL IO? Or is there an alternate recommended configuration for integrating the VOXL IO on the Sentinel platform?

      Any guidance or examples you could provide would be greatly appreciated.

      Eric KatzfeyE Offline
      Eric KatzfeyE Offline
      Eric Katzfey
      ModalAI Team
      wrote on last edited by
      #2

      @tonygurney What are you trying to use the VOXL 2 IO board for?

      T 1 Reply Last reply
      1
      • Eric KatzfeyE Eric Katzfey

        @tonygurney What are you trying to use the VOXL 2 IO board for?

        T Offline
        T Offline
        tonygurney
        Contributor
        wrote on last edited by
        #3

        @Eric-Katzfey I am looking to attach a gripper to the drone

        T 1 Reply Last reply
        0
        • T tonygurney

          @Eric-Katzfey I am looking to attach a gripper to the drone

          T Offline
          T Offline
          tonygurney
          Contributor
          wrote on last edited by
          #4

          @tonygurney I am also using a ghost atto as my receiver

          Eric KatzfeyE 1 Reply Last reply
          0
          • T tonygurney

            @tonygurney I am also using a ghost atto as my receiver

            Eric KatzfeyE Offline
            Eric KatzfeyE Offline
            Eric Katzfey
            ModalAI Team
            wrote on last edited by
            #5

            @tonygurney Did you want to control the gripper using an application on Linux? Or as a driver in PX4?

            T 1 Reply Last reply
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            • Eric KatzfeyE Eric Katzfey

              @tonygurney Did you want to control the gripper using an application on Linux? Or as a driver in PX4?

              T Offline
              T Offline
              tonygurney
              Contributor
              wrote on last edited by
              #6

              @Eric-Katzfey I’m trying to control the gripper using a Python script running in a Docker container on Linux. My plan is to use pymavlink to listen for remote controller commands, like a specific channel input, and then trigger the gripper based on that input. So I think it's not integrated directly as a PX4 driver; it’s more of a companion application running alongside PX4 that reacts to MAVLink messages in real time.

              Eric KatzfeyE 1 Reply Last reply
              0
              • T tonygurney

                @Eric-Katzfey I’m trying to control the gripper using a Python script running in a Docker container on Linux. My plan is to use pymavlink to listen for remote controller commands, like a specific channel input, and then trigger the gripper based on that input. So I think it's not integrated directly as a PX4 driver; it’s more of a companion application running alongside PX4 that reacts to MAVLink messages in real time.

                Eric KatzfeyE Offline
                Eric KatzfeyE Offline
                Eric Katzfey
                ModalAI Team
                wrote on last edited by
                #7

                @tonygurney One option is to use the ESC board. It has PWM outputs. There is a voxl-send-esc-pwm-cmd utility on your VOXL 2 that can be used to send PWM commands to the ESC. However, with this option you would need to solder the PWM connections directly to the ESC board and not everyone is comfortable with that.

                T 1 Reply Last reply
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                • Eric KatzfeyE Eric Katzfey

                  @tonygurney One option is to use the ESC board. It has PWM outputs. There is a voxl-send-esc-pwm-cmd utility on your VOXL 2 that can be used to send PWM commands to the ESC. However, with this option you would need to solder the PWM connections directly to the ESC board and not everyone is comfortable with that.

                  T Offline
                  T Offline
                  tonygurney
                  Contributor
                  wrote on last edited by
                  #8

                  @Eric-Katzfey Correct me if I am wrong, but doesn't the ESC only have enough motor outputs for each of the propellers? So to add another PWM signal I need to either use a GPIO pin or the expansion voxl2 IO board

                  Eric KatzfeyE 1 Reply Last reply
                  0
                  • T tonygurney

                    @Eric-Katzfey Correct me if I am wrong, but doesn't the ESC only have enough motor outputs for each of the propellers? So to add another PWM signal I need to either use a GPIO pin or the expansion voxl2 IO board

                    Eric KatzfeyE Offline
                    Eric KatzfeyE Offline
                    Eric Katzfey
                    ModalAI Team
                    wrote on last edited by
                    #9

                    @tonygurney The ESC doesn't use PWM to control the motors. So it has the PWM channels free for other uses. The ESC used in the Sentinel actually has the PWM IO on a connector (J3) so no need to solder: https://docs.modalai.com/modal-esc-datasheet/

                    T 1 Reply Last reply
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                    • Eric KatzfeyE Eric Katzfey

                      @tonygurney The ESC doesn't use PWM to control the motors. So it has the PWM channels free for other uses. The ESC used in the Sentinel actually has the PWM IO on a connector (J3) so no need to solder: https://docs.modalai.com/modal-esc-datasheet/

                      T Offline
                      T Offline
                      tonygurney
                      Contributor
                      wrote on last edited by
                      #10

                      @Eric-Katzfey How can I control those PWM signals? Since at the moment I am not reading anything from any of the pins.

                      Eric KatzfeyE 1 Reply Last reply
                      0
                      • T tonygurney

                        @Eric-Katzfey How can I control those PWM signals? Since at the moment I am not reading anything from any of the pins.

                        Eric KatzfeyE Offline
                        Eric KatzfeyE Offline
                        Eric Katzfey
                        ModalAI Team
                        wrote on last edited by
                        #11

                        @tonygurney Try the test application voxl-send-esc-pwm-cmd. Source code is here: https://gitlab.com/voxl-public/voxl-sdk/services/voxl-io-server/-/blob/dev/tools/voxl-send-esc-pwm-cmd.c?ref_type=heads

                        T 2 Replies Last reply
                        1
                        • Eric KatzfeyE Eric Katzfey

                          @tonygurney Try the test application voxl-send-esc-pwm-cmd. Source code is here: https://gitlab.com/voxl-public/voxl-sdk/services/voxl-io-server/-/blob/dev/tools/voxl-send-esc-pwm-cmd.c?ref_type=heads

                          T Offline
                          T Offline
                          tonygurney
                          Contributor
                          wrote on last edited by
                          #12

                          @Eric-Katzfey Thank you I got this helped a lot! I was able to get it working with root access!

                          1 Reply Last reply
                          0
                          • Eric KatzfeyE Eric Katzfey

                            @tonygurney Try the test application voxl-send-esc-pwm-cmd. Source code is here: https://gitlab.com/voxl-public/voxl-sdk/services/voxl-io-server/-/blob/dev/tools/voxl-send-esc-pwm-cmd.c?ref_type=heads

                            T Offline
                            T Offline
                            tonygurney
                            Contributor
                            wrote on last edited by
                            #13

                            @Eric-Katzfey when using the voxl-send-esc-pwm-cmd do you know how I would be able to trigger the VREF Pin on the ESC 4-in-1?

                            I have tried running:

                            sudo voxl-send-esc-pwm-cmd -p 12 -w 2201
                            sudo voxl-send-esc-pwm-cmd -p 11 -w 2000

                            and when I measure the voltage from that wire I get ~0.01V which I presume to be noise.

                            Is there something that I am missing?

                            I am looking to produce a 5V Rail.

                            Alex KushleyevA 1 Reply Last reply
                            0
                            • T tonygurney

                              @Eric-Katzfey when using the voxl-send-esc-pwm-cmd do you know how I would be able to trigger the VREF Pin on the ESC 4-in-1?

                              I have tried running:

                              sudo voxl-send-esc-pwm-cmd -p 12 -w 2201
                              sudo voxl-send-esc-pwm-cmd -p 11 -w 2000

                              and when I measure the voltage from that wire I get ~0.01V which I presume to be noise.

                              Is there something that I am missing?

                              I am looking to produce a 5V Rail.

                              Alex KushleyevA Offline
                              Alex KushleyevA Offline
                              Alex Kushleyev
                              ModalAI Team
                              wrote on last edited by Alex Kushleyev
                              #14

                              @tonygurney , I am assuming that you are using the ESC hardware version M0134 (you can confirm using voxl-esc scan tool.

                              Here is the datasheet for M0134.
                              https://docs.modalai.com/modal-esc-datasheet/

                              This ESC has an option (via installing a 0 ohm resistor) to provide 3.3V to pin 1 of J3. This is the same voltage that is used for the MCUs that run on the ESC and should be used with caution (if this voltage rail is brought down by overloading, the ESC will shut down). Please see image below that shows where 0 ohm resistor should be (carefully) installed to enable 3.3V on pin1 of J3 (marked in red)

                              m0134-diagram.jpg

                              If you actually wanted 5V (VAUX), that is available on the other side of the board via two test points at the edge of the board. This voltage rail is provided by a separate switching regulator. See the following section : https://docs.modalai.com/modal-esc-datasheet/#neopixel-led-support

                              If you REALLY need 5V to be present on pin1 of J3, then you can add a small wire jumper from the VAUX test point directly to the pin1 of J3 (which is marked with a white dot). This pin 1 of J3 is normally disconnected. Please only do this if you are comfortable performing this type of soldering and we cannot guarantee the results :).

                              Alex

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