Hilton Tnunay
sdfghj
Diff: MS5611.cpp
- Revision:
- 0:c8bcb12163ab
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/MS5611.cpp Thu Apr 24 12:57:00 2014 +0000
@@ -0,0 +1,353 @@
+//!
+//! @file an520_I2C.c,v
+//!
+//! Copyright (c) 2009 MEAS Switzerland
+//!
+//!
+//!
+//! @brief This C code is for starter reference only. It is written for the
+//! MEAS Switzerland MS56xx pressure sensor modules and Atmel Atmega644p
+//! microcontroller.
+//!
+//! @version 1.0 $Id: an520_I2C.c,v 1.0
+//!
+//! @todo
+
+#include "mbed.h"
+#include "MS5611.h"
+
+double P; // compensated pressure value (mB)
+double T; // compensated temperature value (degC)
+double A; // altitude (ft)
+double S; // sea level barometer (mB)
+
+uint32_t C[8]; //coefficient storage
+
+//--------------------------------------------------------------------------------------------------------------------------------------//
+// Constructor and destructor
+
+MS5611::MS5611(PinName sda, PinName scl) : _i2c(sda, scl) {
+ _i2c.frequency(400000);
+}
+
+//********************************************************
+//! @brief send I2C start condition and the address byte
+//!
+//! @return 0
+//********************************************************
+
+int MS5611::m_i2c_start(bool readMode) {
+ int twst;
+ _i2c.start();
+ if(readMode == true) {
+ twst = m_i2c_write(MS5611_ADDR_R);
+ } else {
+ twst = m_i2c_write(MS5611_ADDR_W);
+ }
+ return(twst);
+}
+
+//********************************************************
+//! @brief send I2C stop condition
+//!
+//! @return none
+//********************************************************
+
+void MS5611::m_i2c_stop(void) {
+ _i2c.stop();
+}
+
+//********************************************************
+//! @brief send I2C stop condition
+//!
+//! @return remote ack status
+//********************************************************
+
+unsigned char MS5611::m_i2c_write(unsigned char data) {
+ int twst = _i2c.write(data);
+ return(twst);
+}
+
+//********************************************************
+//! @brief read I2C byte with acknowledgment
+//!
+//! @return read byte
+//********************************************************
+
+unsigned char MS5611::m_i2c_readAck(void) {
+ int twst = _i2c.read(1);
+ return(twst);
+}
+
+//********************************************************
+//! @brief read I2C byte without acknowledgment
+//!
+//! @return read byte
+//********************************************************
+
+unsigned char MS5611::m_i2c_readNak(void) {
+ int twst = _i2c.read(0);
+ return(twst);
+}
+
+//********************************************************
+//! @brief send command using I2C hardware interface
+//!
+//! @return none
+//********************************************************
+
+void MS5611::m_i2c_send(char cmd) {
+ unsigned char ret;
+ ret = m_i2c_start(false);
+ if(!(ret)) {
+ m_i2c_stop();
+ } else {
+ ret = m_i2c_write(cmd);
+ m_i2c_stop();
+ }
+}
+
+//********************************************************
+//! @brief send reset sequence
+//!
+//! @return none
+//********************************************************
+
+void MS5611::cmd_reset() {
+ m_i2c_send(MS5611_CMD_RESET);
+ wait_ms(4);
+ loadCoefs();
+}
+
+//********************************************************
+//! @brief preform adc conversion
+//!
+//! @return 24bit result
+//********************************************************
+
+unsigned long MS5611::cmd_adc(char cmd) {
+ char cobuf[3];
+ cobuf[0] = 0;
+ cobuf[1] = 0;
+ cobuf[2] = 0;
+ unsigned int ret;
+ unsigned long temp = 0;
+ m_i2c_send(MS5611_CMD_ADC_CONV + cmd);
+ switch (cmd & 0x0f) {
+ case MS5611_CMD_ADC_256 : wait_us(900); break;
+ case MS5611_CMD_ADC_512 : wait_ms(3); break;
+ case MS5611_CMD_ADC_1024: wait_ms(4); break;
+ case MS5611_CMD_ADC_2048: wait_ms(6); break;
+ case MS5611_CMD_ADC_4096: wait_ms(10); break;
+ }
+ m_i2c_send(MS5611_CMD_ADC_READ);
+
+ ret = _i2c.read(MS5611_ADDR_R, cobuf, 3, false);
+ if(ret) printf("\n*** MS5611 ADC Read Error ");
+ temp = (cobuf[0] << 16) + (cobuf[1] << 8) + cobuf[2];
+ return temp;
+}
+
+//********************************************************
+//! @brief Read calibration coefficients
+//!
+//! @return coefficient
+//********************************************************
+
+unsigned int MS5611::cmd_prom(char coef_num) {
+ char cobuf[2];
+ unsigned int ret;
+ unsigned int rC = 0;
+ cobuf[0] = 0;
+ cobuf[1] = 0;
+ m_i2c_send(MS5611_CMD_PROM_RD + coef_num * 2); // send PROM READ command
+ ret = _i2c.read(MS5611_ADDR_R, cobuf, 2, false);
+ if(ret) printf("\n*** MS5611 PROM Read Error ");
+ rC = cobuf[0] * 256 + cobuf[1];
+ return rC;
+}
+
+//********************************************************
+//! @brief calculate the CRC code
+//!
+//! @return crc code
+//********************************************************
+
+unsigned char MS5611::crc4(unsigned int n_prom[]) {
+ unsigned int n_rem;
+ unsigned int crc_read;
+ unsigned char n_bit;
+ n_rem = 0x00;
+ crc_read = n_prom[7];
+ n_prom[7]=(0xFF00 & (n_prom[7]));
+ for (int cnt = 0; cnt < 16; cnt++) {
+ if (cnt%2 == 1) {
+ n_rem ^= (unsigned short) ((n_prom[cnt>>1]) & 0x00FF);
+ } else {
+ n_rem ^= (unsigned short) (n_prom[cnt>>1]>>8);
+ }
+ for (n_bit = 8; n_bit > 0; n_bit--) {
+ if (n_rem & (0x8000)) {
+ n_rem = (n_rem << 1) ^ 0x3000;
+ } else {
+ n_rem = (n_rem << 1);
+ }
+ }
+ }
+ n_rem= (0x000F & (n_rem >> 12));
+ n_prom[7]=crc_read;
+ return (n_rem ^ 0x0);
+}
+
+/*
+The CRC code is calculated and written in factory with the LSB byte in the prom n_prom[7] set to 0x00 (see
+Coefficient table below). It is thus important to clear those bytes from the calculation buffer before proceeding
+with the CRC calculation itself:
+n_prom[7]=(0xFF00 & (n_prom[7])); //CRC byte is replaced by 0
+As a simple test of the CRC code, the following coefficient table could be used:
+unsigned int nprom[] = {0x3132,0x3334,0x3536,0x3738,0x3940,0x4142,0x4344,0x4500};
+the resulting calculated CRC should be 0xB.
+
+DB 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
+Addr
+0 16 bit reserved for manufacturer
+1 Coefficient 1 (16 bit unsigned)
+2 Coefficient 2 (16 bit unsigned)
+3 Coefficient 3 (16 bit unsigned)
+4 Coefficient 4 (16 bit unsigned)
+5 Coefficient 5 (16 bit unsigned)
+6 Coefficient 6 (16 bit unsigned)
+7 0 0 0 0 CRC(0x0)
+*/
+/*
+ //Returns 0x0b as per AP520_004
+ C[0] = 0x3132;
+ C[1] = 0x3334;
+ C[2] = 0x3536;
+ C[3] = 0x3738;
+ C[4] = 0x3940;
+ C[5] = 0x4142;
+ C[6] = 0x4344;
+ C[7] = 0x4546;
+ n_crc = ms.crc4(C); // calculate the CRC
+ pc.printf("testing CRC: 0x%x\n", n_crc);
+*/
+
+//********************************************************
+//! @brief load all calibration coefficients
+//!
+//! @return none
+//********************************************************
+
+void MS5611::loadCoefs() {
+ for (int i = 0; i < 8; i++){
+ wait_ms(50);
+ C[i] = cmd_prom(i);
+ }
+ unsigned char n_crc = crc4(C);
+}
+
+//********************************************************
+//! @brief calculate temperature and pressure
+//!
+//! @return none
+//********************************************************
+
+void MS5611::calcPT() {
+ int32_t D2 = cmd_adc(MS5611_CMD_ADC_D2 + MS5611_CMD_ADC_4096); // read D2
+ int32_t D1 = cmd_adc(MS5611_CMD_ADC_D1 + MS5611_CMD_ADC_4096); // read D1
+ int64_t dT = D2 - ((uint64_t)C[5] << 8);
+ int64_t OFF = ((uint32_t)C[2] << 16) + ((dT * (C[4]) >> 7)); //was OFF = (C[2] << 17) + dT * C[4] / (1 << 6);
+ int64_t SENS = ((uint32_t)C[1] << 15) + ((dT * (C[3]) >> 8)); //was SENS = (C[1] << 16) + dT * C[3] / (1 << 7);
+ T = (2000 + (((uint64_t)dT * C[6]) / (float)(1 << 23))) / 100;
+ int32_t TEMP = 2000 + (int64_t)dT * (int64_t)C[6] / (int64_t)(1 << 23);
+
+ if(TEMP < 2000) { // if temperature lower than 20 Celsius
+ float T1 = (TEMP - 2000) * (TEMP - 2000);
+ int64_t OFF1 = (5 * T1) / 2;
+ int64_t SENS1 = (5 * T1) / 4;
+
+ if(TEMP < -1500) { // if temperature lower than -15 Celsius
+ T1 = (TEMP + 1500) * (TEMP + 1500);
+ OFF1 += 7 * T1;
+ SENS1 += 11 * T1 / 2;
+ }
+ OFF -= OFF1;
+ SENS -= SENS1;
+ T = (float)TEMP / 100;
+ }
+// int64_t P1 = ((((int64_t)D1 * SENS) >> 21) - OFF) >> 15;
+ P = ((((int64_t)D1 * SENS ) >> 21) - OFF) / (double) (1 << 15) / 100.0;
+}
+
+//********************************************************
+//! @brief calculate temperature
+//!
+//! @return double temperature degC
+//********************************************************
+
+double MS5611::calcTemp() {
+ calcPT();
+ return(T);
+}
+
+//********************************************************
+//! @brief calculate pressure
+//!
+//! @return double barometric pressure millibar
+//********************************************************
+
+double MS5611::calcPressure() {
+ calcPT();
+ return(P);
+}
+
+//********************************************************
+//! @brief get pressure, no calculation
+//!
+//! @return double barometric pressure millibar
+//********************************************************
+
+double MS5611::getPressure() {
+ calcPT();
+ return(P);
+}
+
+//********************************************************
+//! @brief get altitude from known sea level barometer,
+//! @ no pre-pressure calculation
+//!
+//! @enter float sea level barometer
+//! @return float altitude in feet
+//********************************************************
+
+float MS5611::getAltitudeFT(float sea_pressure) {
+ A = (1 - (pow((P / (double)sea_pressure), 0.190284))) * 145366.45;
+ return((float)A);
+}
+
+//********************************************************
+//! @brief get sea level pressure from known altitude(ft),
+//! @ no pre-pressure calculation
+//!
+//! @enter float known altitude in feet
+//! @return float seal level barometer in mb
+//********************************************************
+
+float MS5611::getSeaLevelBaroFT(float known_alt) {
+ S = pow(pow((P * INHG), 0.190284) + 0.00001313 * known_alt , 5.2553026) * MB;
+ return((float)S);
+}
+
+//********************************************************
+//! @brief get sea level pressure from known altitude(m),
+//! @ no pre-pressure calculation
+//!
+//! @enter float known altitude in meters
+//! @return float seal level barometer in mb
+//********************************************************
+
+float MS5611::getSeaLevelBaroM(float known_alt) {
+ S = pow(pow((P * INHG), 0.190284) + 0.00001313 * known_alt * FTMETERS , 5.2553026) * MB;
+ return((float)S);
+}