Gremsy Pixy U 3-Axis Gimbal

The Gremsy Pixy U is a 3-axis gimbal that can communicate with the flight controller using the MAVLink protocol, weighs 465g, and is compatible with a range of cameras for real-time video or mapping purposes. More specifications can be found here on the Gremsy website. The user manual is here.

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Where to Buy

The Pixy U can be purchased from the Gremsy store

Connecting to the Autopilot

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We recommend connecting the Gimbals’s COM2 port to one of the autopilot’s Serial/Telemetry ports like Telem2 as shown above.

Connect with a ground station and set the following parameters:

The gimbal’s maximum angles can be set using these parameters:

To control the gimbal’s lean angles from a transmitter set:

  • MNT_RC_IN_TILT to 6 to control the gimbal’s tilt (aka pitch angle) with the transmitter’s Ch6 tuning knob
  • MNT_RC_IN_ROLL to some input channel number to control the gimbal’s roll angle
  • MNT_RC_IN_PAN to some input channel number to control the gimbals’ heading

Gremsy’s instructions can be found below:

Configuring the Gimbal

The gimbal should work without any additional configuration but to improve performance you may need to adjust the gimbal’s gains to match the camera’s weight

  • Download, install and run the gTune setup application
  • Connect the gimbal to your Desktop PC using a USB cable
  • Push the “CONNECTION” button on the left side of the window, then select the COM port and press “Connect”
  • Select the “CONTROLS” tab and ensure “SYNC” is selected so the gimbal communicates with the autopilot using MAVLink
  • Select the “STIFFNESS” tab and adjust the Tilt, Roll and Pan gains so that the gimbal holds the camera in position without shaking

Testing Controlling the Gimbal from RC

  • Powerup the vehicle and gimbal
  • Move the transmitter’s channel 6 tuning knob to its minimum position, the camera should point straight down
  • Move the ch6 knob to maximum and the gimbal should point upwards

Note

The RC’s channel 6 input can be checked from Mission Planner’s Radio calibration page

Testing ROI

The ROI feature points the vehicle and/or camera to point at a target. This can be tested by doing the following:

  • Ensure the vehicle has GPS lock
  • If using the Mission Planner, go to the Flight Data screen and right-mouse-button-click on a point about 50m ahead of the vehicle (the orange and red lines show the vehicle’s current heading), select Point Camera Here and input an altitude of -50 (meters). The camera should point forward and then tilt down at about 45 degrees
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Pilot control of the gimbal can be restored by setting up an auxiliary function switch to “Retract Mount” (i.e. RCx_OPTION = 27) and then move the switch to the lower position