AP_Camera: Adding ability to control the Black Magic Micro Cinema Camera

via SBUS from the flight controller directly.  Handles the flipping of
certain channels.  Relies on change to SRV_Channel to add additional functions.

libraries/AP_Camera/AP_Camera.cpp

@@ -100,6 +100,13 @@ const AP_Param::GroupInfo AP_Camera::var_info[] = {
     // @User: Standard
     AP_GROUPINFO("AUTO_ONLY",  10, AP_Camera, _auto_mode_only, 0),
 
+    // @Param: TYPE
+    // @DisplayName: Type of camera (0: None, 1: BMMCC)
+    // @Description: Set the camera type that is being used, certain cameras have custom functions that need further configuration, this enables that.
+    // @Values: 0:Default,1:BMMCC
+    // @User: Standard
+    AP_GROUPINFO("TYPE",  11, AP_Camera, _type, 0),
+
     AP_GROUPEND
 };
 
@@ -141,8 +148,7 @@ void AP_Camera::trigger_pic()
     setup_feedback_callback();
 
     _image_index++;
-    switch (_trigger_type)
-    {
+    switch (_trigger_type) {
     case AP_CAMERA_TRIGGER_TYPE_SERVO:
         servo_pic();                    // Servo operated camera
         break;
@@ -175,6 +181,16 @@ AP_Camera::trigger_pic_cleanup()
             break;
         }
     }
+
+    if (_trigger_counter_cam_function) {
+        _trigger_counter_cam_function--;
+    } else {
+        switch (_type) {
+        case AP_Camera::CAMERA_TYPE_BMMCC:
+            SRV_Channels::set_output_pwm(SRV_Channel::k_cam_iso, _servo_off_pwm);
+            break;
+        }
+    }
 }
 
 /// decode deprecated MavLink message that controls camera.
@@ -210,6 +226,29 @@ void AP_Camera::configure(float shooting_mode, float shutter_speed, float apertu
 
     // send to all components
     GCS_MAVLINK::send_to_components(&msg);
+
+    if (_type == AP_Camera::CAMERA_TYPE_BMMCC) {
+        // Set a trigger for the additional functions that are flip controlled (so far just ISO and Record Start / Stop use this method, will add others if required)
+        _trigger_counter_cam_function = constrain_int16(_trigger_duration*5,0,255);
+
+        // If the message contains non zero values then use them for the below functions
+        if (ISO > 0) {
+            SRV_Channels::set_output_pwm(SRV_Channel::k_cam_iso, _servo_on_pwm);
+        }
+
+        if (aperture > 0) {
+            SRV_Channels::set_output_pwm(SRV_Channel::k_cam_aperture, (int)aperture);
+        }
+
+        if (shutter_speed > 0) {
+            SRV_Channels::set_output_pwm(SRV_Channel::k_cam_shutter_speed, (int)shutter_speed);
+        }
+
+        // Use the shooting mode PWM value for the BMMCC as the focus control - no need to modify or create a new MAVlink message type.
+        if (shooting_mode > 0) {
+            SRV_Channels::set_output_pwm(SRV_Channel::k_cam_focus, (int)shooting_mode);
+        }
+    }
 }
 
 void AP_Camera::control(float session, float zoom_pos, float zoom_step, float focus_lock, float shooting_cmd, float cmd_id)

libraries/AP_Camera/AP_Camera.h

@@ -46,7 +46,8 @@ public:
     AP_Camera &operator=(const AP_Camera&) = delete;
 
     // get singleton instance
-    static AP_Camera *get_singleton() {
+    static AP_Camera *get_singleton()
+    {
         return _singleton;
     }
 
@@ -60,7 +61,10 @@ public:
     void            control(float session, float zoom_pos, float zoom_step, float focus_lock, float shooting_cmd, float cmd_id);
 
     // set camera trigger distance in a mission
-    void            set_trigger_distance(uint32_t distance_m) { _trigg_dist.set(distance_m); }
+    void            set_trigger_distance(uint32_t distance_m)
+    {
+        _trigg_dist.set(distance_m);
+    }
 
     void take_picture();
 
@@ -73,7 +77,15 @@ public:
     static const struct AP_Param::GroupInfo        var_info[];
 
     // set if vehicle is in AUTO mode
-    void set_is_auto_mode(bool enable) { _is_in_auto_mode = enable; }
+    void set_is_auto_mode(bool enable)
+    {
+        _is_in_auto_mode = enable;
+    }
+
+    enum camera_types {
+        CAMERA_TYPE_STD,
+        CAMERA_TYPE_BMMCC
+    };
 
 private:
 
@@ -85,8 +97,10 @@ private:
     AP_Int16        _servo_on_pwm;      // PWM value to move servo to when shutter is activated
     AP_Int16        _servo_off_pwm;     // PWM value to move servo to when shutter is deactivated
     uint8_t         _trigger_counter;   // count of number of cycles shutter has been held open
+    uint8_t         _trigger_counter_cam_function;   // count of number of cycles alternative camera function has been held open
     AP_Relay       *_apm_relay;         // pointer to relay object from the base class Relay.
     AP_Int8         _auto_mode_only;    // if 1: trigger by distance only if in AUTO mode.
+    AP_Int8         _type;              // Set the type of camera in use, will open additional parameters if set
     bool            _is_in_auto_mode;   // true if in AUTO mode
 
     void            servo_pic();        // Servo operated camera
@@ -132,7 +146,10 @@ private:
     bool check_feedback_pin(void);
 
     // return true if we are using a feedback pin
-    bool using_feedback_pin(void) const { return _feedback_pin > 0; }
+    bool using_feedback_pin(void) const
+    {
+        return _feedback_pin > 0;
+    }
 
 };