HOW TO CONTROL GREMSY GIMBALS VIA SBUS WITH HERELINK
Release date: 11 April 2020
Revision Number: 1.0.2
Gremsy’s Gimbal supports SBUS, SPECTRUM and PPM receivers.
This article will show you how to use S.Bus signal output from a remote controller (Futaba, Herelink, …) for simultaneous control of Autopilot, Gimbal and camera as well.
In this specific example, we will use a T3 gimbal connected directly to Pixhawk’s SBUS.o port, and also connect the third party Seagull #Rec for triggering and zooming the Sony Camera.
Using Remote Control (Herelink):
- Scroll wheel controls the TILT or PAN axis (Channel 10)
- Top button (Right) controls the Gimbal mode including 3 states (Toggle PAN or TILT and Reset Position) (Channel 9)
- C button controls zoom in for camera (Channel 14)
- D button controls zoom out for camera (Channel 14)
- Trigger Camera (Channel 7)
Let’s get started!
1. Items required
- Sony A6/A7 alpha
- Herelink Remote Controller
- Seagull #Rec custom.
- Pixhawk FC.
- T3 Gimbal.
2. Firmware update
The gimbal must be running a firmware version from v7.4.0 or higher and a software v1.4.1 or higher.
3. Hardware setup guide
SBUS port is located on the Hyper Quick Release or the Gimbal Controller.
Connect the FC’s SBUS output port (labelled “SBUSo” on a Cube, “SB” on a Pixhawk) to the gimbal’s SB or “SBUS” port.
b. Seagull #Rec Custom connection
- Connecting MAIN OUT7 with CH1 (Photo & Record).
- Connecting AUX OUT 4 with CH2 (Zoom).
4. Software setup guide
a. Configuring Gimbal
NOTE: This feature will only appear when you upgrade the latest firmware and software. Please see the instructions above.
Open gTune and navigate to SETTINGS à CONTROLS à HERELINK.
There are some parameters to be aware of before controlling gimbal.
- SPEED: Increasing this number will run faster.
- SMOOTH: Increasing this number will smooth out the movement of the corresponding axis but will also cause a delay.
- DEAD ZONE: Input is within deadzone of trim
- REVERSE: Reverse channel input. Set to 0 for normal operation. Set to 1 to reverse this input channel.
b. Configuring Pixhawk FC
Ardupilot allows you to configure a particular port for many purposes. It has 6 AUX Ports (AUX1 – AUX6, referred to as SERVO9-SERVO14 in mission planner).
- Setting SBUS.o
The BRD_SBUS_OUT parameter must be enabled (=1).
SERVO_SBUS_RATE controls the update rate to the servos. The default is 50 Hz but can be set to any value in the range of 25 Hz to 250 Hz.
NOTE: SBUS will output values when switching the safety button. For testing, you should disable the BRD_SAFETY_ENABLE (by setting it to zero).
- Setting the appropriate SERVOxx to RCINxx, RCPassThru
Set default channel SERVO9_FUNCTION for switching between PAN and TILT axis during control.
SERVO9_FUNCTION = 1 (RCPassthru).
Set default channel SERVO10_FUNCTION for controlling gimbal axis (PAN/TILT).
SERVO10_FUNCTION = 1 (RCPassthru).
NOTE: These parameters have been configured in the firmware. DO NOT CHANGE the channels.
- Camera Trigger setup
In mission planner, navigate to INITIAL SETUP-> OPTIONAL HARDWARE -> CAMERA GIMBAL.
- The “shutter” drop-down list is used to set the connected camera trigger port. Here we have selected SERVO9, which corresponds to AUXOUT1 on the Pixhawk. Select Channel 7 that Seagull #Rec custom is connected to PWM1 (Photo & Record). Ex. CH7
- “Pushed” – Set the “Value” for desired trigger mode (AF-T or IS-T see table below)
1400 μS <> 1600 μS
1266 μS <> 1399 μS
1132 μS <> 1265 μS
- "Not Pushed" – Set the value "1500" (Neutral state – see table above)
- "Duration" – Set the value "1" for AF-T mode or "10" for IS-T mode (values may vary depending on how long it takes for your specific camera model and lens configuration to lock focus. Try increasing or decreasing the values to find the sweet spot where the camera can keep up with the duration time that the shutter is held pushed/triggered for).
If you don’t want to use SERVO7, you can choose another channel, but DO NO USE SERVO9-SERVO11. It is used for Gimbal.
- Camera Zooming channel setup
Setting the channel 12 (SERVO12_FUNCTION) to RCPassThru for zooming feature. It means that the value is coming into the FC from the corresponding input channel.
SERVO12_FUNCTION = 1 then channel AUX OUT4 will always equal to channel 12 input from the Herelink.
If you don’t want to use SERVO12, you can choose another channel, but DO NO USE SERVO9 - SERVO11. It is reserved for Gimbal.
c. Configuring Herelink Button
Hereinafter configuring the RC1 with channels for gimbal and camera control.
- Top (Right) Button is assigned for CH9
This channel is reserved for toggling the axis (TILT or PAN). Aside from resetting the home position when pressed about 2 seconds.
Note : Switch type should be set at Monetary switch
- Scroll Wheel Button is assigned for CH10
This channel is reserved for controlling Tilt or Pan.
- C & D Button is assigned for CH12 for zooming.
D long press: Zoom in
C long press: Zoom out.
C & D short press: Reset zoom state as neutral value like below
NOTE: Neutral should be around 1400 μS <> 1600 μS
The value is assigned for D long press and C long press set to speed1. If you want to
move faster, you can find the speed value in the Seagull Rec manual.
The video below shows the T3V3 being tested on Pixhawk Cube and Herelink.
As for the connection and configuration above, you can use the Herelink Remote Controller to control your aircraft with 2 joysticks and button A and B for switch mode or another purpose. Besides, you can also control gimbal with TILT/PAN and camera as well.
a. Check connection
Status LED is solid Blue during operation.
NOTE: The SBUS.o only outputs when the safe button is pressed or the
BRD_SAFETYENABLE = 0. This is only for testing. When pressing the safety button,
you can fly and control the gimbal as well.
b. Control Gimbal
Use the scroll wheel to control TILT/PAN. At that time, only the TILT axis or Pan Axis
is controlled. You can use the TOP (Right) button to toggle axis.
Gimbal will run in FOLLOW mode and allow control PAN in FOLLOW mode, which
is a new feature.
Press the TOP (Right) button for about 2 seconds. Gimbal will return to the home
c. Control Camera
Using SEAGULL #REC custom will avoid twisting the SEAGULL’ cable.
Now you can control zoom in or zoom out with the C and D button.
Long Press D button then the camera will zoom in.
Long Press C button then the camera will zoom out.
If you want to trigger a camera, use the virtual trigger button on the Herelink.
Support page: https://support.gremsy.com/support/home