mirror of
https://github.com/RobTillaart/Arduino.git
synced 2024-10-03 18:09:02 -04:00
479 lines
8.2 KiB
C++
479 lines
8.2 KiB
C++
//
|
||
// FILE: SHT85.cpp
|
||
// AUTHOR: Rob Tillaart
|
||
// VERSION: 0.4.0
|
||
// DATE: 2021-02-10
|
||
// PURPOSE: Arduino library for the SHT85 temperature and humidity sensor
|
||
// https://nl.rs-online.com/web/p/temperature-humidity-sensor-ics/1826530
|
||
// URL: https://github.com/RobTillaart/SHT85
|
||
|
||
|
||
|
||
#include "SHT85.h"
|
||
|
||
|
||
// SUPPORTED COMMANDS - single shot mode only
|
||
#define SHT_READ_STATUS 0xF32D
|
||
#define SHT_CLEAR_STATUS 0x3041
|
||
|
||
#define SHT_SOFT_RESET 0x30A2
|
||
#define SHT_HARD_RESET 0x0006
|
||
|
||
#define SHT_MEASUREMENT_FAST 0x2416 // page 10 datasheet
|
||
#define SHT_MEASUREMENT_SLOW 0x2400 // no clock stretching
|
||
|
||
#define SHT_HEAT_ON 0x306D
|
||
#define SHT_HEAT_OFF 0x3066
|
||
#define SHT_HEATER_TIMEOUT 180000UL // milliseconds
|
||
|
||
|
||
SHT::SHT()
|
||
{
|
||
_address = 0;
|
||
_wire = NULL;
|
||
_lastRead = 0;
|
||
_rawTemperature = 0;
|
||
_rawHumidity = 0;
|
||
_heatTimeout = 0;
|
||
_heaterStart = 0;
|
||
_heaterStop = 0;
|
||
_heaterOn = false;
|
||
_error = SHT_OK;
|
||
_type = 0;
|
||
_temperatureOffset = 0;
|
||
_humidityOffset = 0;
|
||
}
|
||
|
||
|
||
#if defined(ESP8266) || defined(ESP32)
|
||
bool SHT::begin(const uint8_t address, const uint8_t dataPin, const uint8_t clockPin)
|
||
{
|
||
if ((address != 0x44) && (address != 0x45))
|
||
{
|
||
return false;
|
||
}
|
||
_address = address;
|
||
|
||
_wire = &Wire;
|
||
if ((dataPin < 255) && (clockPin < 255))
|
||
{
|
||
_wire->begin(dataPin, clockPin);
|
||
} else {
|
||
_wire->begin();
|
||
}
|
||
return reset();
|
||
}
|
||
|
||
|
||
bool SHT::begin(const uint8_t dataPin, const uint8_t clockPin)
|
||
{
|
||
return begin(SHT_DEFAULT_ADDRESS, dataPin, clockPin);
|
||
}
|
||
#endif
|
||
|
||
|
||
bool SHT::begin(const uint8_t address, TwoWire *wire)
|
||
{
|
||
if ((address != 0x44) && (address != 0x45))
|
||
{
|
||
return false;
|
||
}
|
||
_address = address;
|
||
_wire = wire;
|
||
_wire->begin();
|
||
return reset();
|
||
}
|
||
|
||
|
||
bool SHT::begin(TwoWire *wire)
|
||
{
|
||
return begin(SHT_DEFAULT_ADDRESS, wire);
|
||
}
|
||
|
||
|
||
uint8_t SHT::getType()
|
||
{
|
||
return _type;
|
||
};
|
||
|
||
|
||
///////////////////////////////////////////////////
|
||
//
|
||
// SYNCHRONUOUS interface
|
||
//
|
||
bool SHT::read(bool fast)
|
||
{
|
||
requestData(fast);
|
||
while(dataReady(fast) == false) yield();
|
||
return readData(fast);
|
||
}
|
||
|
||
|
||
///////////////////////////////////////////////////
|
||
//
|
||
// ASYNCHRONUOUS interface
|
||
//
|
||
bool SHT::requestData(bool fast)
|
||
{
|
||
if (writeCmd(fast ? SHT_MEASUREMENT_FAST : SHT_MEASUREMENT_SLOW) == false)
|
||
{
|
||
return false;
|
||
}
|
||
_lastRequest = millis();
|
||
return true;
|
||
}
|
||
|
||
|
||
bool SHT::dataReady(bool fast)
|
||
{
|
||
return ((millis() - _lastRequest) > (fast ? 4 : 15));
|
||
}
|
||
|
||
|
||
bool SHT::readData(bool fast)
|
||
{
|
||
uint8_t buffer[6];
|
||
if (readBytes(6, (uint8_t*) &buffer[0]) == false)
|
||
{
|
||
return false;
|
||
}
|
||
|
||
if (!fast)
|
||
{
|
||
if (buffer[2] != crc8(buffer, 2))
|
||
{
|
||
_error = SHT_ERR_CRC_TEMP;
|
||
return false;
|
||
}
|
||
if (buffer[5] != crc8(buffer + 3, 2))
|
||
{
|
||
_error = SHT_ERR_CRC_HUM;
|
||
return false;
|
||
}
|
||
}
|
||
|
||
_rawTemperature = (buffer[0] << 8) + buffer[1];
|
||
_rawHumidity = (buffer[3] << 8) + buffer[4];
|
||
|
||
_lastRead = millis();
|
||
|
||
return true;
|
||
}
|
||
|
||
|
||
uint32_t SHT::lastRequest()
|
||
{
|
||
return _lastRequest;
|
||
};
|
||
|
||
|
||
///////////////////////////////////////////////////
|
||
//
|
||
// STATUS
|
||
//
|
||
bool SHT::isConnected()
|
||
{
|
||
_wire->beginTransmission(_address);
|
||
int rv = _wire->endTransmission();
|
||
if (rv != 0) _error = SHT_ERR_NOT_CONNECT;
|
||
return (rv == 0);
|
||
}
|
||
|
||
#ifdef doc
|
||
// bit - description
|
||
// ==================
|
||
// 15 Alert pending status
|
||
// '0': no pending alerts
|
||
// '1': at least one pending alert - default
|
||
// 14 Reserved ‘0’
|
||
// 13 Heater status
|
||
// '0’ : Heater OFF - default
|
||
// '1’ : Heater ON
|
||
// 12 Reserved '0’
|
||
// 11 Humidity tracking alert
|
||
// '0’ : no alert - default
|
||
// '1’ : alert
|
||
// 10 Temp tracking alert
|
||
// '0’ : no alert - default
|
||
// '1’ : alert
|
||
// 9:5 Reserved '00000’
|
||
// 4 System reset detected
|
||
// '0': no reset since last ‘clear status register’ command
|
||
// '1': reset detected (hard or soft reset command or supply fail) - default
|
||
// 3:2 Reserved ‘00’
|
||
// 1 Command status
|
||
// '0': last command executed successfully
|
||
// '1': last command not processed. Invalid or failed checksum
|
||
// 0 Write data checksum status
|
||
// '0': checksum of last write correct
|
||
// '1': checksum of last write transfer failed
|
||
#endif
|
||
|
||
|
||
uint16_t SHT::readStatus()
|
||
{
|
||
uint8_t status[3] = { 0, 0, 0 };
|
||
// page 13 datasheet
|
||
if (writeCmd(SHT_READ_STATUS) == false)
|
||
{
|
||
return 0xFFFF;
|
||
}
|
||
// 16 bit status + CRC
|
||
if (readBytes(3, (uint8_t*) &status[0]) == false)
|
||
{
|
||
return 0xFFFF;
|
||
}
|
||
|
||
if (status[2] != crc8(status, 2))
|
||
{
|
||
_error = SHT_ERR_CRC_STATUS;
|
||
return 0xFFFF;
|
||
}
|
||
|
||
return (uint16_t) (status[0] << 8) + status[1];
|
||
}
|
||
|
||
|
||
uint32_t SHT::lastRead()
|
||
{
|
||
return _lastRead;
|
||
};
|
||
|
||
|
||
bool SHT::reset(bool hard)
|
||
{
|
||
bool b = writeCmd(hard ? SHT_HARD_RESET : SHT_SOFT_RESET);
|
||
if (b == false)
|
||
{
|
||
return false;
|
||
}
|
||
delay(1); // table 4 datasheet
|
||
return true;
|
||
}
|
||
|
||
|
||
int SHT::getError()
|
||
{
|
||
int rv = _error;
|
||
_error = SHT_OK;
|
||
return rv;
|
||
}
|
||
|
||
|
||
///////////////////////////////////////////////////
|
||
//
|
||
// HEATER
|
||
//
|
||
void SHT::setHeatTimeout(uint8_t seconds)
|
||
{
|
||
_heatTimeout = seconds;
|
||
if (_heatTimeout > 180) _heatTimeout = 180;
|
||
}
|
||
|
||
|
||
uint8_t SHT::getHeatTimeout()
|
||
{
|
||
return _heatTimeout;
|
||
};
|
||
|
||
|
||
bool SHT::heatOn()
|
||
{
|
||
if (isHeaterOn()) return true;
|
||
if ((_heaterStop > 0) && (millis() - _heaterStop < SHT_HEATER_TIMEOUT))
|
||
{
|
||
_error = SHT_ERR_HEATER_COOLDOWN;
|
||
return false;
|
||
}
|
||
if (writeCmd(SHT_HEAT_ON) == false)
|
||
{
|
||
_error = SHT_ERR_HEATER_ON;
|
||
return false;
|
||
}
|
||
_heaterStart = millis();
|
||
_heaterOn = true;
|
||
return true;
|
||
}
|
||
|
||
|
||
bool SHT::heatOff()
|
||
{
|
||
// always switch off the heater - ignore _heaterOn flag.
|
||
if (writeCmd(SHT_HEAT_OFF) == false)
|
||
{
|
||
_error = SHT_ERR_HEATER_OFF; // can be serious!
|
||
return false;
|
||
}
|
||
_heaterStop = millis();
|
||
_heaterOn = false;
|
||
return true;
|
||
}
|
||
|
||
|
||
bool SHT::isHeaterOn()
|
||
{
|
||
if (_heaterOn == false)
|
||
{
|
||
return false;
|
||
}
|
||
// did not exceed time out
|
||
if (millis() - _heaterStart < (_heatTimeout * 1000UL))
|
||
{
|
||
return true;
|
||
}
|
||
heatOff();
|
||
return false;
|
||
}
|
||
|
||
|
||
//////////////////////////////////////////////////////////
|
||
//
|
||
// TEMPERATURE & HUMIDITY
|
||
//
|
||
float SHT::getHumidity()
|
||
{
|
||
float hum = _rawHumidity * (100.0 / 65535);
|
||
if (_humidityOffset != 0) hum += _humidityOffset;
|
||
return hum;
|
||
}
|
||
|
||
|
||
float SHT::getTemperature()
|
||
{
|
||
float temp = _rawTemperature * (175.0 / 65535) - 45;
|
||
if (_temperatureOffset != 0) temp += _temperatureOffset;
|
||
return temp;
|
||
}
|
||
|
||
|
||
float SHT::getFahrenheit()
|
||
{
|
||
float temp = _rawTemperature * (63.0 / 13107.0) - 49;
|
||
if (_temperatureOffset != 0) temp += _temperatureOffset * 1.8;
|
||
return temp;
|
||
}
|
||
|
||
|
||
uint16_t SHT::getRawHumidity()
|
||
{
|
||
return _rawHumidity;
|
||
}
|
||
|
||
|
||
uint16_t SHT::getRawTemperature()
|
||
{
|
||
return _rawTemperature;
|
||
}
|
||
|
||
|
||
void SHT::setTemperatureOffset(float offset)
|
||
{
|
||
_temperatureOffset = offset;
|
||
}
|
||
|
||
|
||
float SHT::getTemperatureOffset()
|
||
{
|
||
return _temperatureOffset;
|
||
}
|
||
|
||
|
||
void SHT::setHumidityOffset(float offset)
|
||
{
|
||
_humidityOffset = offset;
|
||
}
|
||
|
||
|
||
float SHT::getHumidityOffset()
|
||
{
|
||
return _humidityOffset;
|
||
}
|
||
|
||
|
||
|
||
|
||
|
||
//////////////////////////////////////////////////////////
|
||
//
|
||
// PROTECTED
|
||
//
|
||
uint8_t SHT::crc8(const uint8_t *data, uint8_t len)
|
||
{
|
||
// CRC-8 formula from page 14 of SHT spec pdf
|
||
const uint8_t POLY(0x31);
|
||
uint8_t crc(0xFF);
|
||
|
||
for (uint8_t j = len; j; --j)
|
||
{
|
||
crc ^= *data++;
|
||
|
||
for (uint8_t i = 8; i; --i)
|
||
{
|
||
crc = (crc & 0x80) ? (crc << 1) ^ POLY : (crc << 1);
|
||
}
|
||
}
|
||
return crc;
|
||
}
|
||
|
||
|
||
bool SHT::writeCmd(uint16_t cmd)
|
||
{
|
||
_wire->beginTransmission(_address);
|
||
_wire->write(cmd >> 8 );
|
||
_wire->write(cmd & 0xFF);
|
||
if (_wire->endTransmission() != 0)
|
||
{
|
||
_error = SHT_ERR_WRITECMD;
|
||
return false;
|
||
}
|
||
return true;
|
||
}
|
||
|
||
|
||
bool SHT::readBytes(uint8_t n, uint8_t *val)
|
||
{
|
||
int rv = _wire->requestFrom(_address, (uint8_t) n);
|
||
if (rv == n)
|
||
{
|
||
for (uint8_t i = 0; i < n; i++)
|
||
{
|
||
val[i] = _wire->read();
|
||
}
|
||
return true;
|
||
}
|
||
_error = SHT_ERR_READBYTES;
|
||
return false;
|
||
}
|
||
|
||
|
||
////////////////////////////////////////////////////////
|
||
//
|
||
// DERIVED CLASSES
|
||
//
|
||
SHT30::SHT30()
|
||
{
|
||
_type = 30;
|
||
};
|
||
|
||
|
||
SHT31::SHT31()
|
||
{
|
||
_type = 31;
|
||
};
|
||
|
||
|
||
SHT35::SHT35()
|
||
{
|
||
_type = 35;
|
||
};
|
||
|
||
|
||
SHT85::SHT85()
|
||
{
|
||
_type = 85;
|
||
};
|
||
|
||
|
||
// -- END OF FILE --
|
||
|