VTT TinyNode, slightly modified code from example (https://developer.mbed.org/users/jejuho/code/VTT_NODEV3_BMP180_Si7021)
Dependencies: BLE_API TMP_nrf51 mbed nRF51822
Fork of VTT_NODEV3_BMP180_Si7021 by
Si7021.cpp
- Committer:
- jejuho
- Date:
- 2016-01-25
- Revision:
- 2:b221ba23b37f
File content as of revision 2:b221ba23b37f:
#include "Si7021.h" SI7021_I2C::SI7021_I2C(PinName sda, PinName scl) : i2c_(sda, scl) { //400kHz, allowing us to use the fastest data rates. i2c_.frequency(400000); } uint8_t SI7021_I2C::readBytes(uint8_t *values, int8_t length, bool waitConversion) { uint8_t Status=0; if(!i2c_.write(SI7021_ADDR, (const char*)values, 1,0)) Status=1; //Wait the measurement time if(waitConversion) wait_ms(23); if(!i2c_.read(SI7021_ADDR, (char*)values, length,0)) Status=1; return(Status); } float SI7021_I2C::Measure_Temp(void) { float Temperature; uint16_t ConvValue; uint8_t *Ptr; uint8_t Data[2]; Data[0]=SI7021_MEASURE_TEMPERATURE_HOLD_MASTER; if(readBytes(Data,2, 1)) { Ptr=(uint8_t*)&ConvValue; Ptr[0]=Data[1]; Ptr[1]=Data[0]; Temperature=(((float)ConvValue)/65536)*175-46.85; } else { Temperature=1234; } return(Temperature); } float SI7021_I2C::get_HumidityTemp(void) { float Temperature; uint16_t ConvValue; uint8_t *Ptr; uint8_t Data[2]; Data[0]=SI7021_READ_TEMPERATURE; if(readBytes(Data,2, 0)) { Ptr=(uint8_t*)&ConvValue; Ptr[0]=Data[1]; Ptr[1]=Data[0]; Temperature=(((float)ConvValue)/65536)*175-46.85; } else { Temperature=1234; } return(Temperature); } void SI7021_I2C::Measure_Humidity_Temp(float *humidity, float *temperature) { float Humidity; uint16_t ConvValueHum; uint8_t *Ptr; uint8_t Data[2]; Data[0]=SI7021_MEASURE_RH_NO_HOLD_MASSTER; if(readBytes(Data,2, 1)) { Ptr=(uint8_t*)&ConvValueHum; Ptr[0]=Data[1]; Ptr[1]=Data[0]; Humidity=(((float)ConvValueHum)/65536)*125-6; if(Humidity<0) Humidity=0; if(Humidity>100) Humidity=100; } else Humidity=1234; *humidity = Humidity; *temperature = get_HumidityTemp(); }