AP_InertialSensor: Return product ID from sensor initialization

this exposes the product ID to the IMU Layer

libraries/AP_InertialSensor/AP_InertialSensor.h

@@ -13,7 +13,7 @@ class AP_InertialSensor
   public:
   AP_InertialSensor() {}
 
-  virtual void init( AP_PeriodicProcess * scheduler ) = 0;
+  virtual uint16_t init( AP_PeriodicProcess * scheduler ) = 0;
 
   /* Update the sensor data, so that getters are nonblocking.
    * Returns a bool of whether data was updated or not.

libraries/AP_InertialSensor/AP_InertialSensor_MPU6000.cpp

@@ -119,14 +119,15 @@ AP_InertialSensor_MPU6000::AP_InertialSensor_MPU6000( uint8_t cs_pin )
   _initialised = 0;
 }
 
-void AP_InertialSensor_MPU6000::init( AP_PeriodicProcess * scheduler )
+uint16_t AP_InertialSensor_MPU6000::init( AP_PeriodicProcess * scheduler )
 {
-    if (_initialised) return;
+    if (_initialised) return _product_id;
     _initialised = 1;
     scheduler->suspend_timer();
     hardware_init();
     scheduler->resume_timer();
     scheduler->register_process( &AP_InertialSensor_MPU6000::read );
+	return _product_id;
 }
 
 // accumulation in ISR - must be read with interrupts disabled

libraries/AP_InertialSensor/AP_InertialSensor_MPU6000.h

@@ -16,7 +16,7 @@ class AP_InertialSensor_MPU6000 : public AP_InertialSensor
 
   AP_InertialSensor_MPU6000( uint8_t cs_pin );
 
-  void init( AP_PeriodicProcess * scheduler );
+  uint16_t init( AP_PeriodicProcess * scheduler );
 
   /* Concrete implementation of AP_InertialSensor functions: */
   bool update();

libraries/AP_InertialSensor/AP_InertialSensor_Oilpan.cpp

@@ -48,9 +48,17 @@ AP_InertialSensor_Oilpan::AP_InertialSensor_Oilpan( AP_ADC * adc ) :
   _accel.z = 0;
 }
 
-void AP_InertialSensor_Oilpan::init( AP_PeriodicProcess * scheduler)
+uint16_t AP_InertialSensor_Oilpan::init( AP_PeriodicProcess * scheduler)
 {
   _adc->Init(scheduler);
+
+#if defined(DESKTOP_BUILD)
+	return AP_PRODUCT_ID_SITL;
+#elif defined(__AVR_ATmega1280__)
+	return AP_PRODUCT_ID_APM1_1280;
+#else
+	return AP_PRODUCT_ID_APM1_2560;
+#endif
 }
 
 bool AP_InertialSensor_Oilpan::update()

libraries/AP_InertialSensor/AP_InertialSensor_Oilpan.h

@@ -17,7 +17,7 @@ class AP_InertialSensor_Oilpan : public AP_InertialSensor
   AP_InertialSensor_Oilpan( AP_ADC * adc );
 
   /* Concrete implementation of AP_InertialSensor functions: */
-  void init(AP_PeriodicProcess * scheduler);
+  uint16_t init(AP_PeriodicProcess * scheduler);
   bool update();
   bool new_data_available();
   float gx();

libraries/AP_InertialSensor/AP_InertialSensor_Stub.cpp

@@ -2,7 +2,9 @@
 
 #include "AP_InertialSensor_Stub.h"
 
-void AP_InertialSensor_Stub::init( AP_PeriodicProcess * scheduler ) {}
+uint16_t AP_InertialSensor_Stub::init( AP_PeriodicProcess * scheduler ) {
+	return AP_PRODUCT_ID_NONE;
+}
 
 /*================ AP_INERTIALSENSOR PUBLIC INTERFACE ==================== */
 

libraries/AP_InertialSensor/AP_InertialSensor_Stub.h

@@ -15,7 +15,7 @@ class AP_InertialSensor_Stub : public AP_InertialSensor
 
   AP_InertialSensor_Stub() {}
 
-  void init( AP_PeriodicProcess * scheduler );
+  uint16_t init( AP_PeriodicProcess * scheduler );
 
   /* Concrete implementation of AP_InertialSensor functions: */
   bool update();