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GimbalCtrl

The GimbalCtrl controls nick, roll and yaw of an AlexMos Brushless Gimbal.

Optionally, up to 3 switching outputs can be used (e.g. to trigger a photo camera).

During a waypoint flight you can control the angle for nick exactly. The nick- and roll angle will also be recorded in the LOG-File and also in TXT-File.

Connection

Connect the GimbalCtrl with the I2C-Bus of your MikroKopter FlightCtrl. The output will be connected to GND, Rx and Tx of the serial input of your AlexMos-PCB.

GimbalCtrl - LED

the GimbalCtrl has a red and green led:

• green LED => ON

• red LED => fast flashing

  => GimbalCtrl is connect via I2C on your FlightCtrl. Brushless Gimbal was not recognized (the connection is wrong, gimbal is OFF ...)

• green LED => flashing slow

• red LED => OFF

  => GimbalCtrl is connect via I2C on your FlightCtrl. Brushless Gimbal was detected.

Setting AlexMos

Change the serial speed for RC_SERIAL port / UART2 port in your AlexMos-PCB down to 9600 Baud.

INFO: When you setup the AlexMos-PCB remove the GimbalCtrl.

If you use a 3-axes Gimbal you have to activate also FollowYAW.

Setting KopterTool

To control the Funktion nick, roll and yaw via the GimbalCtrl you need 3 free channels.

You can setup this channes under Camera (nick, roll) and CamCtrl (YAW Channel) in the KopterTool.

I2C-Adapter for 3-axes Gimbal

On an 3-axes gimbal you can damage external routed cable if you yaw the gimbal.
It the gimbal offers 4 free wires via the sliding contact in the yaw motor you can also route the I2C bus down to the gimbal.

In the example on the right you can see how the I2C bus can be looped through.

To make such an adapter you need:

• - 1x I2C-Bus Splitter
  - 2x Servo cable extension
  - 1x 4pol Molex cabel

If this is done you can use on the gimbal the GimbalCtrl and also the CamCtrl at the same time.

So you use several functions over only a few cables and prevents entanglement while yawing the gimbal.

Switching outputs

Optionally, up to 3 switching outputs can be used. So you can e.g. trigger a camera or switch something else.

INFO: The switching outputs are max. 100mA loadable !!!
Do you want to switch more load (z.B. LED-Streifen) please use e.g. a ExtensionPCB.

With the KopterTool you can set the switching output Out1/Out2 with a free channel.
(CamCtrl -> Out1/Out2)

The switching output "Trigger" is parallel with the "switching output 1" of your FlightCtrl.

Angle

If you control a gimbal with a servo connection, the set angle (in a waypoint flight) is not the real angle. The number you set for the angle is added to the servo value.

With the GimbalCtrl you can set and use now the real angle. So when you set e.g. 90 for the angle, the gimbal will look 90° down.

LOG-File - TXT-File

The inclination of the gimbal for nick and roll in degrees is stored continuously in the LOG file in the column Gimbal.



In addition, the nick / roll angle is recorded in the extra TXT file for each triggered photo.

Particularities

On AlexMos boards type extended (first revisoins), the "Tx" port is designed low resistance.
In this case, the GimbalCtrl can not connect. Also not if the connection and the settings are correct.

On this board you can connect the GimbalCtrl with the second serial port.
Please note that you need the latest software on your AlexMos board (SW V2.66b2 or newer). With older SW the second serial port will not work..

Setup:

• RC-Setting

  • RC_ROLL pin mode => SBGC Serial API

• Hardware

  • Main serial port speed => 11520

  • RC_SERIAL port speed => 9600

  • UART2 port speed => 9600

  

Separate supply with two Lipos

The GimbalCtrl has a high-impedance protective resistor between the GND terminals. If you use now one Lipo for your copter and a seperate lipo only for your brushless gimbal you have to connect the GND of both lipos together. Otherwise the GimbalCtrl will not work.

Attention: Make sure that the polarity is correct when connecting.