SITL: added emulated airspeed sensor on a pin

libraries/AP_HAL_AVR_SITL/AnalogIn.cpp

@@ -12,7 +12,8 @@ using namespace AVR_SITL;
 
 extern const AP_HAL::HAL& hal;
 
-ADCSource::ADCSource(uint8_t pin, float prescale) :
+ADCSource::ADCSource(SITL_State *sitlState, uint8_t pin, float prescale) :
+    _sitlState(sitlState),
     _pin(pin),
     _prescale(prescale)
 {}
@@ -25,6 +26,10 @@ float ADCSource::read_latest() {
     switch (_pin) {
     case ANALOG_INPUT_BOARD_VCC:
         return 4900;
+        
+    case 0:
+        return _sitlState->airspeed_pin_value;
+
     case ANALOG_INPUT_NONE:
     default:
         return 0.0;
@@ -35,8 +40,6 @@ void ADCSource::set_pin(uint8_t pin) {
     _pin = pin;
 }
 
-SITLAnalogIn::SITLAnalogIn() {}
-
 void SITLAnalogIn::init(void *ap_hal_scheduler) {
 }
 
@@ -45,7 +48,7 @@ AP_HAL::AnalogSource* SITLAnalogIn::channel(int16_t pin) {
 }
 
 AP_HAL::AnalogSource* SITLAnalogIn::channel(int16_t pin, float prescale) {
-    return new ADCSource(pin, prescale);	
+    return new ADCSource(_sitlState, pin, prescale);	
 }
 
 #endif

libraries/AP_HAL_AVR_SITL/AnalogIn.h

@@ -12,7 +12,7 @@ public:
     friend class AVR_SITL::SITLAnalogIn;
     /* pin designates the ADC input number, or when == AVR_ANALOG_PIN_VCC,
      * board vcc */
-    ADCSource(uint8_t pin, float prescale = 1.0);
+    ADCSource(SITL_State *sitlState, uint8_t pin, float prescale = 1.0);
 
     /* implement AnalogSource virtual api: */
     float read_average();
@@ -21,6 +21,7 @@ public:
 
 private:
     /* prescale scales the raw measurments for read()*/
+    SITL_State *_sitlState;
     uint8_t _pin;
     const float _prescale;
 };
@@ -29,14 +30,16 @@ private:
  * timer event and the AP_HAL::AnalogIn interface */
 class AVR_SITL::SITLAnalogIn : public AP_HAL::AnalogIn {
 public:
-    SITLAnalogIn();
+    SITLAnalogIn(SITL_State *sitlState) {
+	_sitlState = sitlState;
+    }
     void init(void* ap_hal_scheduler);
     AP_HAL::AnalogSource* channel(int16_t n);
     AP_HAL::AnalogSource* channel(int16_t n, float prescale);
 
 private:
     static ADCSource* _channels[SITL_INPUT_MAX_CHANNELS];
-
+    SITL_State *_sitlState;
 };
 
 #endif // __AP_HAL_AVR_SITL_ANALOG_IN_H__

libraries/AP_HAL_AVR_SITL/HAL_AVR_SITL_Class.cpp

@@ -29,7 +29,7 @@ static SITLConsoleDriver consoleDriver;
 static SITL_State sitlState;
 static SITLRCInput  sitlRCInput(&sitlState);
 static SITLRCOutput sitlRCOutput(&sitlState);
-static SITLAnalogIn sitlAnalogIn;
+static SITLAnalogIn sitlAnalogIn(&sitlState);
 
 static Empty::EmptyGPIO emptyGPIO;
 

libraries/AP_HAL_AVR_SITL/SITL_State.cpp

@@ -31,6 +31,7 @@ struct sockaddr_in SITL_State::_rcout_addr;
 pid_t SITL_State::_parent_pid;
 uint32_t SITL_State::_update_count;
 bool SITL_State::_motors_on;
+uint16_t SITL_State::airspeed_pin_value;
 
 AP_Baro_BMP085_HIL *SITL_State::_barometer;
 AP_InertialSensor_Stub *SITL_State::_ins;

libraries/AP_HAL_AVR_SITL/SITL_State.h

@@ -39,6 +39,9 @@ public:
     static uint16_t pwm_input[8];
     static void loop_hook(void);
 
+    // simulated airspeed
+    static uint16_t airspeed_pin_value;
+
 private:
     void _parse_command_line(int argc, char * const argv[]);
     void _usage(void);

libraries/AP_HAL_AVR_SITL/sitl_ins.cpp

@@ -119,6 +119,8 @@ void SITL_State::_update_ins(float roll, 	float pitch, 	float yaw,		// Relative
 
 	_ins->set_gyro(Vector3f(p, q, r));
 	_ins->set_accel(Vector3f(xAccel, yAccel, zAccel));
+
+	airspeed_pin_value = _airspeed_sensor(airspeed);
 }
 
 #endif