GY-63_MS5611/libraries/MS5611/MS5611.cpp
2022-10-27 16:52:08 +02:00

321 lines
7.1 KiB
C++

//
// FILE: MS5611.cpp
// AUTHOR: Rob Tillaart
// Erni - testing/fixes
// VERSION: 0.3.9
// PURPOSE: MS5611 Temperature & Humidity library for Arduino
// URL: https://github.com/RobTillaart/MS5611
//
// HISTORY see changelog.md
#include "MS5611.h"
// datasheet page 10
#define MS5611_CMD_READ_ADC 0x00
#define MS5611_CMD_READ_PROM 0xA0
#define MS5611_CMD_RESET 0x1E
#define MS5611_CMD_CONVERT_D1 0x40
#define MS5611_CMD_CONVERT_D2 0x50
/////////////////////////////////////////////////////
//
// PUBLIC
//
MS5611::MS5611(uint8_t deviceAddress)
{
_address = deviceAddress;
_samplingRate = OSR_ULTRA_LOW;
_temperature = MS5611_NOT_READ;
_pressure = MS5611_NOT_READ;
_result = MS5611_NOT_READ;
_lastRead = 0;
_deviceID = 0;
_pressureOffset = 0;
_temperatureOffset = 0;
_compensation = true;
}
#if defined (ESP8266) || defined(ESP32)
bool MS5611::begin(uint8_t dataPin, uint8_t clockPin, TwoWire * wire)
{
if ((_address < 0x76) || (_address > 0x77)) return false;
_wire = wire;
if ((dataPin < 255) && (clockPin < 255))
{
_wire->begin(dataPin, clockPin);
} else {
_wire->begin();
}
if (! isConnected()) return false;
return reset();
}
#endif
bool MS5611::begin(TwoWire * wire)
{
if ((_address < 0x76) || (_address > 0x77)) return false;
_wire = wire;
_wire->begin();
if (! isConnected()) return false;
return reset();
}
bool MS5611::isConnected()
{
_wire->beginTransmission(_address);
#ifdef ARDUINO_ARCH_NRF52840
// needed for NANO 33 BLE
_wire->write(0);
#endif
return (_wire->endTransmission() == 0);
}
bool MS5611::reset(uint8_t mathMode)
{
command(MS5611_CMD_RESET);
uint32_t start = micros();
// while loop prevents blocking RTOS
while (micros() - start < 2800)
{
yield();
delayMicroseconds(10);
}
// initialize the C[] array
initConstants(mathMode);
// read factory calibrations from EEPROM.
bool ROM_OK = true;
for (uint8_t reg = 0; reg < 7; reg++)
{
// used indices match datasheet.
// C[0] == manufacturer - read but not used;
// C[7] == CRC - skipped.
uint16_t tmp = readProm(reg);
C[reg] *= tmp;
// _deviceID is a SHIFT XOR merge of 7 PROM registers, reasonable unique
_deviceID <<= 4;
_deviceID ^= tmp;
// Serial.println(readProm(reg));
if (reg > 0)
{
ROM_OK = ROM_OK && (tmp != 0);
}
}
return ROM_OK;
}
int MS5611::read(uint8_t bits)
{
// VARIABLES NAMES BASED ON DATASHEET
// ALL MAGIC NUMBERS ARE FROM DATASHEET
convert(MS5611_CMD_CONVERT_D1, bits);
if (_result) return _result;
// NOTE: D1 and D2 seem reserved in MBED (NANO BLE)
uint32_t _D1 = readADC();
if (_result) return _result;
convert(MS5611_CMD_CONVERT_D2, bits);
if (_result) return _result;
uint32_t _D2 = readADC();
if (_result) return _result;
// Serial.println(_D1);
// Serial.println(_D2);
// TEST VALUES - comment lines above
// uint32_t _D1 = 9085466;
// uint32_t _D2 = 8569150;
// TEMP & PRESS MATH - PAGE 7/20
float dT = _D2 - C[5];
_temperature = 2000 + dT * C[6];
float offset = C[2] + dT * C[4];
float sens = C[1] + dT * C[3];
if (_compensation)
{
// SECOND ORDER COMPENSATION - PAGE 8/20
// COMMENT OUT < 2000 CORRECTION IF NOT NEEDED
// NOTE TEMPERATURE IS IN 0.01 C
if (_temperature < 2000)
{
float T2 = dT * dT * 4.6566128731E-10;
float t = (_temperature - 2000) * (_temperature - 2000);
float offset2 = 2.5 * t;
float sens2 = 1.25 * t;
// COMMENT OUT < -1500 CORRECTION IF NOT NEEDED
if (_temperature < -1500)
{
t = (_temperature + 1500) * (_temperature + 1500);
offset2 += 7 * t;
sens2 += 5.5 * t;
}
_temperature -= T2;
offset -= offset2;
sens -= sens2;
}
// END SECOND ORDER COMPENSATION
}
_pressure = (_D1 * sens * 4.76837158205E-7 - offset) * 3.051757813E-5;
_lastRead = millis();
return MS5611_READ_OK;
}
void MS5611::setOversampling(osr_t samplingRate)
{
_samplingRate = (uint8_t) samplingRate;
}
float MS5611::getTemperature() const
{
if (_temperatureOffset == 0) return _temperature * 0.01;
return _temperature * 0.01 + _temperatureOffset;
};
float MS5611::getPressure() const
{
if (_pressureOffset == 0) return _pressure * 0.01;
return _pressure * 0.01 + _pressureOffset;
};
// EXPERIMENTAL
uint16_t MS5611::getManufacturer()
{
return readProm(0);
}
// EXPERIMENTAL
uint16_t MS5611::getSerialCode()
{
return readProm(7) >> 4;
}
/////////////////////////////////////////////////////
//
// PRIVATE
//
void MS5611::convert(const uint8_t addr, uint8_t bits)
{
// values from page 3 datasheet - MAX column (rounded up)
uint16_t del[5] = {600, 1200, 2300, 4600, 9100};
uint8_t index = bits;
if (index < 8) index = 8;
else if (index > 12) index = 12;
index -= 8;
uint8_t offset = index * 2;
command(addr + offset);
uint16_t waitTime = del[index];
uint32_t start = micros();
// while loop prevents blocking RTOS
while (micros() - start < waitTime)
{
yield();
delayMicroseconds(10);
}
}
uint16_t MS5611::readProm(uint8_t reg)
{
// last EEPROM register is CRC - Page 13 datasheet.
uint8_t promCRCRegister = 7;
if (reg > promCRCRegister) return 0;
uint8_t offset = reg * 2;
command(MS5611_CMD_READ_PROM + offset);
if (_result == 0)
{
uint8_t length = 2;
int bytes = _wire->requestFrom(_address, length);
if (bytes >= length)
{
uint16_t value = _wire->read() * 256;
value += _wire->read();
return value;
}
return 0;
}
return 0;
}
uint32_t MS5611::readADC()
{
command(MS5611_CMD_READ_ADC);
if (_result == 0)
{
uint8_t length = 3;
int bytes = _wire->requestFrom(_address, length);
if (bytes >= length)
{
uint32_t value = _wire->read() * 65536UL;
value += _wire->read() * 256UL;
value += _wire->read();
return value;
}
return 0UL;
}
return 0UL;
}
int MS5611::command(const uint8_t command)
{
yield();
_wire->beginTransmission(_address);
_wire->write(command);
_result = _wire->endTransmission();
return _result;
}
void MS5611::initConstants(uint8_t mathMode)
{
// constants that were multiplied in read() - datasheet page 8
// do this once and you save CPU cycles
//
// datasheet ms5611 | appNote
// mode = 0; | mode = 1
C[0] = 1;
C[1] = 32768L; // SENSt1 = C[1] * 2^15 | * 2^16
C[2] = 65536L; // OFFt1 = C[2] * 2^16 | * 2^17
C[3] = 3.90625E-3; // TCS = C[3] / 2^8 | / 2^7
C[4] = 7.8125E-3; // TCO = C[4] / 2^7 | / 2^6
C[5] = 256; // Tref = C[5] * 2^8 | * 2^8
C[6] = 1.1920928955E-7; // TEMPSENS = C[6] / 2^23 | / 2^23
if (mathMode == 1) // Appnote version for pressure.
{
C[1] = 65536L; // SENSt1
C[2] = 131072L; // OFFt1
C[3] = 7.8125E-3; // TCS
C[4] = 1.5625e-2; // TCO
}
}
// -- END OF FILE --