// // FILE: MS5611.cpp // AUTHOR: Rob Tillaart // Erni - testing/fixes // VERSION: 0.3.5 // PURPOSE: MS5611 Temperature & Humidity library for Arduino // URL: https://github.com/RobTillaart/MS5611 // // HISTORY: // 0.3.5 2022-01-13 fix isConnected() for NANO 33 BLE // 0.3.4 2021-12-29 fix #16 compilation for MBED // 0.3.3 2021-12-25 Update oversampling timings to reduce time spent waiting // 0.3.2 2021-12-24 add get/set oversampling, read() (thanks to LyricPants66133) // 0.3.1 2021-12-21 update library.json, readme, license, minor edits // 0.3.0 2021-01-27 fix #9 math error (thanks to Emiel Steerneman) // add Wire1..WireN support (e.g. teensy) // changed getTemperature() and getPressure() // add reset() // // 0.2.2 2021-01-01 add Arduino-CI + unit tests + isConnected() // 0.2.1 2020-06-28 fix #1 min macro compile error // 0.2.0 2020-06-21 refactor; #pragma once; // // 0.1.8 fix #109 incorrect constants (thanks to flauth) // 0.1.7 revert double to float (issue 33) // 0.1.6 2015-07-12 refactor // 0.1.05 moved 6 float multiplies to init [adds ~70 bytes !!!] // moved the MS5611_LIB_VERSION to PROGMEM // 0.1.04 changed float to double (for platforms which support it) // changed divisions in multiplications // fixed uint32_t readADC() // reduced size of C array by 1 float // added second order temperature compensation // 0.1.03 changed math to float [test version] // 0.1.02 fixed bug return value read() // fixed bug #bits D2 // added MS5611_READ_OK // added inline getters for temp & pres & lastResult. // adjusted delay's based on datasheet // merged convert functions // fixed offset in readProm() // 0.1.01 small refactoring // 0.1.00 added temperature and Pressure code // 0.0.00 initial version by Rob Tillaart (15-okt-2014) #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; } #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; reset(); return true; } #endif bool MS5611::begin(TwoWire * wire) { if ((_address < 0x76) || (_address > 0x77)) return false; _wire = wire; _wire->begin(); if (! isConnected()) return false; reset(); return true; } bool MS5611::isConnected() { _wire->beginTransmission(_address); _wire->write(0); // needed for NANO 33 BLE return (_wire->endTransmission() == 0); } void MS5611::reset() { command(MS5611_CMD_RESET); delayMicroseconds(2800); // constants that were multiplied in read() // do this once and you save CPU cycles C[0] = 1; C[1] = 32768L; // SENSt1 = C[1] * 2^15 C[2] = 65536L; // OFFt1 = C[2] * 2^16 C[3] = 3.90625E-3; // TCS = C[3] / 2^6 C[4] = 7.8125E-3; // TCO = C[4] / 2^7 C[5] = 256; // Tref = C[5] * 2^8 C[6] = 1.1920928955E-7; // TEMPSENS = C[6] / 2^23 // read factory calibrations from EEPROM. for (uint8_t reg = 0; reg < 7; reg++) { // used indices match datasheet. // C[0] == manufacturer - read but not used; // C[7] == CRC - skipped. C[reg] *= readProm(reg); } } 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; // 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]; // 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; } ///////////////////////////////////////////////////// // // PRIVATE // void MS5611::convert(const uint8_t addr, uint8_t bits) { //Values from page 2 datasheet uint16_t del[5] = {500, 1100, 2100, 4100, 8220}; bits = constrain(bits, 8, 12); uint8_t offset = (bits - 8) * 2; command(addr + offset); delayMicroseconds(del[offset/2]); } uint16_t MS5611::readProm(uint8_t reg) { // last EEPROM register is CRC - Page13 datasheet. uint8_t promCRCRegister = 7; if (reg > promCRCRegister) return 0; uint8_t offset = reg * 2; command(MS5611_CMD_READ_PROM + offset); if (_result == 0) { int nr = _wire->requestFrom(_address, (uint8_t)2); if (nr >= 2) { uint16_t val = _wire->read() * 256; val += _wire->read(); return val; } return 0; } return 0; } uint32_t MS5611::readADC() { command(MS5611_CMD_READ_ADC); if (_result == 0) { int nr = _wire->requestFrom(_address, (uint8_t)3); if (nr >= 3) { uint32_t val = _wire->read() * 65536UL; val += _wire->read() * 256UL; val += _wire->read(); return val; } return 0UL; } return 0UL; } int MS5611::command(const uint8_t command) { yield(); _wire->beginTransmission(_address); _wire->write(command); _result = _wire->endTransmission(); return _result; } // -- END OF FILE --