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V.06 11/3
Dependencies: FT6206 SDFileSystem SPI_TFT_ILI9341 TFT_fonts
Fork of ATT_AWS_IoT_demo by
Sensors/Temperature/hts221_driver.cpp
- Committer:
- ampembeng
- Date:
- 2016-12-07
- Revision:
- 20:ee34856ae510
File content as of revision 20:ee34856ae510:
#include "HTS221.h" // ------------------------------------------------------------------------------ //jmf -- define I2C pins and functions to read & write to I2C device #include <string> #include "mbed.h" #include "hardware.h" //I2C i2c(PTC11, PTC10); //SDA, SCL -- define the I2C pins being used. Defined in a //common locatioin since sensors also use I2C // Read a single unsigned char from addressToRead and return it as a unsigned char unsigned char HTS221::readRegister(unsigned char slaveAddress, unsigned char ToRead) { char data = ToRead; i2c.write(slaveAddress, &data, 1, 1); i2c.read(slaveAddress, &data, 1, 0); return data; } // Writes a single unsigned char (dataToWrite) into regToWrite int HTS221::writeRegister(unsigned char slaveAddress, unsigned char regToWrite, unsigned char dataToWrite) { const char data[] = {regToWrite, dataToWrite}; return i2c.write(slaveAddress,data,2,0); } //jmf end // ------------------------------------------------------------------------------ //static inline int humidityReady(uint8_t data) { // return (data & 0x02); //} //static inline int temperatureReady(uint8_t data) { // return (data & 0x01); //} HTS221::HTS221(void) : _address(HTS221_ADDRESS) { _temperature = 0; _humidity = 0; } int HTS221::begin(void) { uint8_t data; data = readRegister(_address, WHO_AM_I); if (data == WHO_AM_I_RETURN){ if (activate()){ storeCalibration(); return data; } } return 0; } int HTS221::storeCalibration(void) { uint8_t data; uint16_t tmp; for (int reg=CALIB_START; reg<=CALIB_END; reg++) { if ((reg!=CALIB_START+8) && (reg!=CALIB_START+9) && (reg!=CALIB_START+4)) { data = readRegister(HTS221_ADDRESS, reg); switch (reg) { case CALIB_START: _h0_rH = data; break; case CALIB_START+1: _h1_rH = data; break; case CALIB_START+2: _T0_degC = data; break; case CALIB_START+3: _T1_degC = data; break; case CALIB_START+5: tmp = _T0_degC; _T0_degC = (data&0x3)<<8; _T0_degC |= tmp; tmp = _T1_degC; _T1_degC = ((data&0xC)>>2)<<8; _T1_degC |= tmp; break; case CALIB_START+6: _H0_T0 = data; break; case CALIB_START+7: _H0_T0 |= data<<8; break; case CALIB_START+0xA: _H1_T0 = data; break; case CALIB_START+0xB: _H1_T0 |= data <<8; break; case CALIB_START+0xC: _T0_OUT = data; break; case CALIB_START+0xD: _T0_OUT |= data << 8; break; case CALIB_START+0xE: _T1_OUT = data; break; case CALIB_START+0xF: _T1_OUT |= data << 8; break; case CALIB_START+8: case CALIB_START+9: case CALIB_START+4: //DO NOTHING break; // to cover any possible error default: return false; } /* switch */ } /* if */ } /* for */ return true; } int HTS221::activate(void) { uint8_t data; data = readRegister(_address, CTRL_REG1); data |= POWER_UP; data |= ODR0_SET; writeRegister(_address, CTRL_REG1, data); return true; } int HTS221::deactivate(void) { uint8_t data; data = readRegister(_address, CTRL_REG1); data &= ~POWER_UP; writeRegister(_address, CTRL_REG1, data); return true; } int HTS221::bduActivate(void) { uint8_t data; data = readRegister(_address, CTRL_REG1); data |= BDU_SET; writeRegister(_address, CTRL_REG1, data); return true; } int HTS221::bduDeactivate(void) { uint8_t data; data = readRegister(_address, CTRL_REG1); data &= ~BDU_SET; writeRegister(_address, CTRL_REG1, data); return true; } int HTS221::readHumidity(void) { uint8_t data = 0; uint16_t h_out = 0; double h_temp = 0.0; double hum = 0.0; data = readRegister(_address, STATUS_REG); if (data & HUMIDITY_READY) { data = readRegister(_address, HUMIDITY_H_REG); h_out = data << 8; // MSB data = readRegister(_address, HUMIDITY_L_REG); h_out |= data; // LSB // Decode Humidity hum = ((int16_t)(_h1_rH) - (int16_t)(_h0_rH))/2.0; // remove x2 multiple // Calculate humidity in decimal of grade centigrades i.e. 15.0 = 150. h_temp = (((int16_t)h_out - (int16_t)_H0_T0) * hum) / ((int16_t)_H1_T0 - (int16_t)_H0_T0); hum = ((int16_t)_h0_rH) / 2.0; // remove x2 multiple _humidity = (int16_t)((hum + h_temp)); // provide signed % measurement unit } return _humidity; } double HTS221::readTemperature(void) { uint8_t data = 0; uint16_t t_out = 0; double t_temp = 0.0; double deg = 0.0; data = readRegister(_address, STATUS_REG); if (data & TEMPERATURE_READY) { data= readRegister(_address, TEMP_H_REG); t_out = data << 8; // MSB data = readRegister(_address, TEMP_L_REG); t_out |= data; // LSB // Decode Temperature deg = ((int16_t)(_T1_degC) - (int16_t)(_T0_degC))/8.0; // remove x8 multiple // Calculate Temperature in decimal of grade centigrades i.e. 15.0 = 150. t_temp = (((int16_t)t_out - (int16_t)_T0_OUT) * deg) / ((int16_t)_T1_OUT - (int16_t)_T0_OUT); deg = ((int16_t)_T0_degC) / 8.0; // remove x8 multiple _temperature = deg + t_temp; // provide signed celsius measurement unit } return _temperature; }