MS5611 arduino code

#define MS5611_ADDRESS (0x77) #define MS5611_CMD_ADC_READ (0x00) #define MS5611_CMD_RESET (0x1E) #define MS5611_CMD_CONV_D1 (0x40) #define MS5611_CMD_CONV_D2 (0x50) #define MS5611_CMD_READ_PROM (0xA2) typedef enum { MS5611_ULTRA_HIGH_RES = 0x08, MS5611_HIGH_RES = 0x06, MS5611_STANDARD = 0x04, MS5611_LOW_POWER = 0x02, MS5611_ULTRA_LOW_POWER = 0x00 } ms5611_osr_t; class MS5611 { public: bool begin(ms5611_osr_t osr = MS5611_HIGH_RES); uint32_t readRawTemperature(void); uint32_t readRawPressure(void); double readTemperature(bool compensation = false); int32_t readPressure(bool compensation = false); double getAltitude(double pressure, double seaLevelPressure = 101325); double getSeaLevel(double pressure, double altitude); void setOversampling(ms5611_osr_t osr); ms5611_osr_t getOversampling(void); private: uint16_t fc[6]; uint8_t ct; uint8_t uosr; int32_t TEMP2; int64_t OFF2, SENS2; void reset(void); void readPROM(void); uint16_t readRegister16(uint8_t reg); uint32_t readRegister24(uint8_t reg); }; #include <Wire.h> #include <math.h> #include <MS5611.h> bool MS5611::begin(ms5611_osr_t osr) { Wire.begin(); reset(); setOversampling(osr); delay(100); readPROM(); return true; } // Set oversampling value void MS5611::setOversampling(ms5611_osr_t osr) { switch (osr) { case MS5611_ULTRA_LOW_POWER: ct = 1; break; case MS5611_LOW_POWER: ct = 2; break; case MS5611_STANDARD: ct = 3; break; case MS5611_HIGH_RES: ct = 5; break; case MS5611_ULTRA_HIGH_RES: ct = 10; break; } uosr = osr; } // Get oversampling value ms5611_osr_t MS5611::getOversampling(void) { return (ms5611_osr_t)uosr; } void MS5611::reset(void) { Wire.beginTransmission(MS5611_ADDRESS); #if ARDUINO >= 100 Wire.write(MS5611_CMD_RESET); #else Wire.send(MS5611_CMD_RESET); #endif Wire.endTransmission(); } void MS5611::readPROM(void) { for (uint8_t offset = 0; offset < 6; offset++) { fc[offset] = readRegister16(MS5611_CMD_READ_PROM + (offset * 2)); } } uint32_t MS5611::readRawTemperature(void) { Wire.beginTransmission(MS5611_ADDRESS); #if ARDUINO >= 100 Wire.write(MS5611_CMD_CONV_D2 + uosr); #else Wire.send(MS5611_CMD_CONV_D2 + uosr); #endif Wire.endTransmission(); delay(ct); return readRegister24(MS5611_CMD_ADC_READ); } uint32_t MS5611::readRawPressure(void) { Wire.beginTransmission(MS5611_ADDRESS); #if ARDUINO >= 100 Wire.write(MS5611_CMD_CONV_D1 + uosr); #else Wire.send(MS5611_CMD_CONV_D1 + uosr); #endif Wire.endTransmission(); delay(ct); return readRegister24(MS5611_CMD_ADC_READ); } int32_t MS5611::readPressure(bool compensation) { uint32_t D1 = readRawPressure(); uint32_t D2 = readRawTemperature(); int32_t dT = D2 - (uint32_t)fc[4] * 256; int64_t OFF = (int64_t)fc[1] * 65536 + (int64_t)fc[3] * dT / 128; int64_t SENS = (int64_t)fc[0] * 32768 + (int64_t)fc[2] * dT / 256; if (compensation) { int32_t TEMP = 2000 + ((int64_t) dT * fc[5]) / 8388608; OFF2 = 0; SENS2 = 0; if (TEMP < 2000) { OFF2 = 5 * ((TEMP - 2000) * (TEMP - 2000)) / 2; SENS2 = 5 * ((TEMP - 2000) * (TEMP - 2000)) / 4; } if (TEMP < -1500) { OFF2 = OFF2 + 7 * ((TEMP + 1500) * (TEMP + 1500)); SENS2 = SENS2 + 11 * ((TEMP + 1500) * (TEMP + 1500)) / 2; } OFF = OFF - OFF2; SENS = SENS - SENS2; } uint32_t P = (D1 * SENS / 2097152 - OFF) / 32768; return P; } double MS5611::readTemperature(bool compensation) { uint32_t D2 = readRawTemperature(); int32_t dT = D2 - (uint32_t)fc[4] * 256; int32_t TEMP = 2000 + ((int64_t) dT * fc[5]) / 8388608; TEMP2 = 0; if (compensation) { if (TEMP < 2000) { TEMP2 = (dT * dT) / (2 << 30); } } TEMP = TEMP - TEMP2; return ((double)TEMP/100); } // Calculate altitude from Pressure & Sea level pressure double MS5611::getAltitude(double pressure, double seaLevelPressure) { return (44330.0f * (1.0f - pow((double)pressure / (double)seaLevelPressure, 0.1902949f))); } // Calculate sea level from Pressure given on specific altitude double MS5611::getSeaLevel(double pressure, double altitude) { return ((double)pressure / pow(1.0f - ((double)altitude / 44330.0f), 5.255f)); } // Read 16-bit from register (oops MSB, LSB) uint16_t MS5611::readRegister16(uint8_t reg) { uint16_t value; Wire.beginTransmission(MS5611_ADDRESS); #if ARDUINO >= 100 Wire.write(reg); #else Wire.send(reg); #endif Wire.endTransmission(); Wire.beginTransmission(MS5611_ADDRESS); Wire.requestFrom(MS5611_ADDRESS, 2); while(!Wire.available()) {}; #if ARDUINO >= 100 uint8_t vha = Wire.read(); uint8_t vla = Wire.read(); #else uint8_t vha = Wire.receive(); uint8_t vla = Wire.receive(); #endif; Wire.endTransmission(); value = vha << 8 | vla; return value; } // Read 24-bit from register (oops XSB, MSB, LSB) uint32_t MS5611::readRegister24(uint8_t reg) { uint32_t value; Wire.beginTransmission(MS5611_ADDRESS); #if ARDUINO >= 100 Wire.write(reg); #else Wire.send(reg); #endif Wire.endTransmission(); Wire.beginTransmission(MS5611_ADDRESS); Wire.requestFrom(MS5611_ADDRESS, 3); while(!Wire.available()) {}; #if ARDUINO >= 100 uint8_t vxa = Wire.read(); uint8_t vha = Wire.read(); uint8_t vla = Wire.read(); #else uint8_t vxa = Wire.receive(); uint8_t vha = Wire.receive(); uint8_t vla = Wire.receive(); #endif; Wire.endTransmission(); value = ((int32_t)vxa << 16) | ((int32_t)vha << 8) | vla; return value; }

Reference : https://github.com/jarzebski/Arduino-MS5611