Si702x_Driver

Silicon Labs Si7020/21 I2C Relative Humidity and Temperature Sensor Driver.

1. Override the weak read and write functions according to platform. (Default functions implemented for STM32)
   • void si702x_read(uint16_t addr, uint8_t addr_len, uint8_t *data, uint8_t len)
   • void si702x_write(uint16_t addr, uint8_t addr_len, uint8_t *data, uint8_t len)
2. Init the driver with handler.
   • si702x_init(&hi2c1);
3. Change the resolution if needed. (Low resolution-> Lower Conversion Time -> Lower Current Consumption.) Default: 12-bit RH , 14-bit temperature
   • si702x_set_resolution(RH10_TEMP13);
4. Read data with get temperature and humidity methods.Initiating a RH measurement will also automatically initiate a temperature measurement.
   • float rh = si702x_get_rh_hold_master();
   • float temp = si702x_get_temp_prev_meas();
5. Internal heater can be used to test sensor or deal with condensation and high humidity.
   • //For example 0x00 = 3mA, 0x08 = 51mA, 0x0F = 94mA (maximum)
   • si702x_set_heater_level(0x0F) // HeaterCurrent(mA) = HeaterLevel*3 + 6
   • si702x_enable_heater(true);
6. Debug messages can be disabled by commenting #define SI702x_DEBUG line.