Gimbal: Added rc channel control readme

Author: snktshrma

Diff for: README.md

@@ -232,6 +232,46 @@ Display the streamed video:
 gst-launch-1.0 -v udpsrc port=5600 caps='application/x-rtp, media=(string)video, clock-rate=(int)90000, encoding-name=(string)H264' ! rtph264depay ! avdec_h264 ! videoconvert ! autovideosink sync=false
 ```
 
+View the streamed camera frames in [QGC](http://qgroundcontrol.com/):
+
+`Open QGC > Application Settings > Video Settings > Select UDP h.264 Video Stream & use port 5600`
+
+![QGC settings](https://private-user-images.githubusercontent.com/74557164/344478908-f55242f3-cff8-4f81-befd-da68e4df73c6.png?jwt=eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.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.48sEOYbBONNEA-0qYevB7z_NleKW_zL-hNSefu5UYaQ)
+
+### 4. Using 3d Gimbal
+
+The Iris model is equipped with a 3d gimbal and camera that can be controlled directly in MAVProxy using the RC overrides.
+
+#### Run Gazebo
+
+```bash
+gz sim -v4 -r iris_runway.sdf
+```
+
+#### Run ArduPilot SITL with a specified parameter file
+
+```bash
+cd ardupilot
+
+sim_vehicle.py -D -v ArduCopter -f JSON --add-param-file=$HOME/ardupilot_gazebo/config/gazebo-iris-gimbal.parm --console --map
+```
+
+Control action for gimbal over RC channel:
+
+| Action | Channel | RC Low | RC High |
+| ------------- | ------------- | ------------- | ------------- |
+| Roll | RC6 | Roll Left | Roll Right |
+| Pitch | RC7 | Pitch Down | Pitch Up |
+| Yaw | RC8 | Yaw Left | Yaw Right |
+
+Example usage:
+
+`rc 6 1000` - Gimbal rolls left
+
+`rc 7 2000` - Gimbal pitch upwards
+
+`rc 8 1500` - Gimbal yaw neutral
+
 ## Models
 
 In addition to the Iris and Zephyr models included here, a selection

Diff for: config/gazebo-iris-gimbal.parm

@@ -14,17 +14,21 @@ RNGFND1_SCALING  10
 RNGFND1_PIN      0
 RNGFND1_MAX_CM   5000
 
-# Gimbal on mount 1 has 2 DOF
+# Gimbal on mount 1 has 3 DOF
 MNT1_PITCH_MAX   90
 MNT1_PITCH_MIN   -90
 MNT1_ROLL_MAX    90
 MNT1_ROLL_MIN    -90
+MNT1_YAW_MAX    90
+MNT1_YAW_MIN    -90
 MNT1_TYPE        1
 
-# Gimbal roll and pitch RC
-RC9_OPTION       212
-RC10_OPTION      213
+# Gimbal roll, pitch and yaw RC
+RC6_OPTION      212
+RC7_OPTION      213
+RC8_OPTION      214
 
-# Gimbal roll and pitch servos
-SERVO5_FUNCTION  8
-SERVO6_FUNCTION  7
+# Gimbal roll, pitch and yaw servos
+SERVO9_FUNCTION  8
+SERVO10_FUNCTION  7
+SERVO11_FUNCTION  6