AP_Baro: make AP_SerialBus::write() return success or failure for MS56XX

libraries/AP_Baro/AP_Baro_MS5611.cpp

@@ -76,10 +76,11 @@ uint32_t AP_SerialBus_SPI::read_24bits(uint8_t reg)
     return (((uint32_t)rx[1])<<16) | (((uint32_t)rx[2])<<8) | ((uint32_t)rx[3]);
 }
 
-void AP_SerialBus_SPI::write(uint8_t reg)
+bool AP_SerialBus_SPI::write(uint8_t reg)
 {
     uint8_t tx[1] = { reg };
     _spi->transaction(tx, NULL, 1);
+    return true;
 }
 
 bool AP_SerialBus_SPI::sem_take_blocking() 
@@ -132,9 +133,9 @@ uint32_t AP_SerialBus_I2C::read_24bits(uint8_t reg)
     return 0;
 }
 
-void AP_SerialBus_I2C::write(uint8_t reg)
+bool AP_SerialBus_I2C::write(uint8_t reg)
 {
-    _i2c->write(_addr, 1, &reg);
+    return _i2c->write(_addr, 1, &reg) == 0;
 }
 
 bool AP_SerialBus_I2C::sem_take_blocking() 

libraries/AP_Baro/AP_Baro_MS5611.h

@@ -20,7 +20,7 @@ public:
     virtual uint32_t read_24bits(uint8_t reg) = 0;
 
     /** Write to a register with no data. */
-    virtual void write(uint8_t reg) = 0;
+    virtual bool write(uint8_t reg) = 0;
 
     /** Acquire the internal semaphore for this device.
      * take_nonblocking should be used from the timer process,
@@ -41,7 +41,7 @@ public:
     uint16_t read_16bits(uint8_t reg);
     uint32_t read_24bits(uint8_t reg);
     uint32_t read_adc(uint8_t reg);
-    void write(uint8_t reg);
+    bool write(uint8_t reg);
     bool sem_take_nonblocking();
     bool sem_take_blocking();
     void sem_give();
@@ -61,7 +61,7 @@ public:
     void init();
     uint16_t read_16bits(uint8_t reg);
     uint32_t read_24bits(uint8_t reg);
-    void write(uint8_t reg);
+    bool write(uint8_t reg);
     bool sem_take_nonblocking();
     bool sem_take_blocking();
     void sem_give();