Gremsy T3, T7, Pixy and Mio 3-Axis Gimbals

Gremsy T3, T7, Pixy WP, Pixy U, Pixy F and Mio 3-axis gimbals can communicate with the flight controller using the MAVLink protocol and are compatible with a range of cameras for real-time video or mapping purposes.

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Where to Buy

The Pixy and Mio gimbals can be purchased from the Gremsy store

Connecting to the Autopilot (4.3 or higher)

If using ArduPilot 4.3 (or higher) please follow these setup instructions

../_images/gremsy-pixyu-autopilot.png

Connect the gimbals’s COM2 port to one of the autopilot’s Serial/Telemetry ports like Telem2 as shown above.

Connect to the autopilot with a ground station and set the following parameters, if using the first mount:

  • MNT1_TYPE to “6” for “Gremsy” and reboot the autopilot

  • SERIAL2_BAUD to “115” for 115200 bps. “SERIAL2” can be replaced with another serial port (i.e. SERIAL1) depending upon the physical connection

  • SERIAL2_PROTOCOL to 2 for “MAVLink2”

  • SERIAL2_OPTIONS to 1024 for “Don’t forward mavlink to/from”

  • Optionally set RC9_OPTION to 163 for “Mount Lock” to allow the pilot to switch between “lock” and “follow” modes during “RC Targetting”. Note “RC9” can be replaced with any RC input channel

When the autopilot has successfully connected to the gimbal, “Mount: GREMSY PixyU fw:7.7.1.0” (or similar) will be sent to the ground station. Looking for this message may be useful in determining if the autopilot and gimbal are communicating successfully.

Configuring the Gimbal

  • Download and install gTune Desktop

  • Connect the gimbal to your Desktop PC using a USB cable and power on the gimbal

  • Use gTune Desktop to check the gimbal firmware version

    • Open gTune Desktop application, “Found your device” should be displayed

    • Select “CONNECT”

    • Select “INFO” and confirm the gimbal is running Firmware “7.7.1” or higher

    ../_images/gremsy-firmware-version-check.png
    • If the gimbal firmware is older than 7.7.1 download the latest .hex for T3, T7, Pixy W, Pixy U, Pixy F or Mio

    • Select “UPGRADE”, “BROWSE” and select the file downloaded above

    • Press the other “UPGRADE” button and the upgrade should complete within 30 seconds

    ../_images/gremsy-settings-upgrade.png
  • Use gTune Desktop to configure the gimbal

    • Select “SETTINGS”, “CONTROLS” and ensure “SYNC” is selected so the gimbal communicates with the autopilot using MAVLink

    ../_images/gremsy-settings-sync.png
    • Select “Settings”, “REDUCE DIRFT by DRONE”

    ../_images/gremsy-settings-reduce-drift-by-drone.png
  • 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

  • Disconnect the USB cable connecting your PC to the gimbal

  • 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 pitch down at about 45 degrees

../_images/Tarot_BenchTestROI.jpg

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

Connecting Two Gimbals

If two Gremsy gimbals are used, each gimbal can be directly connected to one of the autopilot’s serial ports or they can can be daisy-chained together with only one connected to one of the autopilot’s serial ports.

  • Use the gTune desktop application set the second gimbal’s MAVLink component id to “GIMBAL_COMPID2”

    ../_images/gremsy-settings-compid.png
  • Connect a GCS to your autopilot and set

    • MNT2_TYPE to “6” for “Gremsy” and reboot the autopilot

    • set the appropriate SERIALx_BAUD, SERIALx_PROTOCOL and SERIALx_OPTIONS parameters as described above

Connecting to the Autopilot (4.2 or earlier)

../_images/gremsy-pixyu-autopilot.png

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, if using the first mount:

  • MNT1_TYPE to “4” for “SToRM32 MavLink” and reboot the autopilot

  • SERIAL2_BAUD to “115” for 115200 bps. “SERIAL2” can be replaced with another serial port (i.e. SERIAL1) depending upon the physical connection

  • SERIAL2_PROTOCOL to 2 for “MAVLink2”

  • SR2_EXTRA1 to 10

  • SR2_POSITION to 10

The gimbal’s maximum angles can be set using these parameters (shown for the first mount):

To control the gimbal’s lean angles from a transmitter set the RC controls for roll, pitch, or yaw using RCx_OPTION 212 (Mount1 Roll), 213 (Mount1 Pitch), 214 (Mount1 Yaw) for the first mount, or 215-217 for the second mount, respectively.

Gremsy’s instructions can be found below: