Line data    Source code

       1             : #include "AP_TemperatureSensor_config.h"
       2             : 
       3             : #if AP_TEMPERATURE_SENSOR_MLX90614_ENABLED
       4             : 
       5             : #include "AP_TemperatureSensor_MLX90614.h"
       6             : 
       7             : #include <AP_HAL/AP_HAL.h>
       8             : #include <AP_HAL/I2CDevice.h>
       9             : #include <AP_Math/AP_Math.h>
      10             : 
      11             : 
      12             : extern const AP_HAL::HAL &hal;
      13             : 
      14             : #define MLX90614_I2CDEFAULTADDR 0x5A    // Device default slave address 
      15             : #define MLX90614_BROADCASTADDR  0       // Device broadcast slave address 
      16             : 
      17             : //  RAM addresses
      18             : #define MLX90614_RAWIR1         0x04    //  RAM reg - Raw temperature, source #1 
      19             : #define MLX90614_RAWIR2         0x05    //  RAM reg - Raw temperature, source #2 
      20             : #define MLX90614_TA             0x06    //  RAM reg - Linearized temperature, ambient 
      21             : #define MLX90614_TOBJ1          0x07    //  RAM reg - Linearized temperature, source #1 
      22             : #define MLX90614_TOBJ2          0x08    //  RAM reg - Linearized temperature, source #2 
      23             : 
      24           0 : void AP_TemperatureSensor_MLX90614::init()
      25             : {
      26           0 :     _params.bus_address.set_default(MLX90614_I2CDEFAULTADDR);
      27             :     
      28           0 :     _dev = hal.i2c_mgr->get_device_ptr(_params.bus, _params.bus_address);
      29           0 :     if (!_dev) {
      30           0 :         return;
      31             :     }
      32             : 
      33           0 :     WITH_SEMAPHORE(_dev->get_semaphore());
      34             : 
      35           0 :     _dev->register_periodic_callback(50 * AP_USEC_PER_MSEC,
      36             :                                      FUNCTOR_BIND_MEMBER(&AP_TemperatureSensor_MLX90614::_timer, void));
      37           0 : }
      38             : 
      39             : 
      40           0 : void AP_TemperatureSensor_MLX90614::_timer()
      41             : {
      42           0 :     const uint16_t _crude_value = read_data(MLX90614_TA);
      43             :     
      44           0 :     if (_crude_value == 0) {
      45           0 :         return;
      46             :     }
      47             : 
      48           0 :     WITH_SEMAPHORE(_dev->get_semaphore());
      49             :         
      50             :     // temp * 0.02 - 273.15 = degrees, temp * 0.02 is temperature in kelvin
      51           0 :     const float tmp = KELVIN_TO_C(_crude_value * 0.02);
      52           0 :     set_temperature(tmp);
      53           0 : }
      54             : 
      55             : 
      56             : 
      57           0 : uint16_t AP_TemperatureSensor_MLX90614::read_data(uint8_t cmd)
      58             : {
      59             :     uint8_t val[3];
      60             :   
      61           0 :     if (!_dev->transfer(&cmd, 1, val, 3)) {
      62           0 :         return 0;
      63             :     }
      64           0 :     return UINT16_VALUE(val[1],val[0]);
      65             : }
      66             : #endif // AP_TEMPERATURE_SENSOR_MLX90614_ENABLED