UAVRO / ms5611

High resolution barometer and altimeter using i2c mode

Dependents:   Q2_Stabi

Fork of ms5611 by Kevin Braun

ms5611.h@6:41c370fa1f7b, 2013-06-24 (annotated)

Committer:
loopsva
Date:
Mon Jun 24 19:11:28 2013 +0000
Revision:
6:41c370fa1f7b
Parent:
5:0d7b229474c6
Child:
7:90ee2168baa7
Updated .h documentation and added i2c frequency set in .cpp file.

Who changed what in which revision?

UserRevisionLine numberNew contents of line
loopsva 0:f97f410d4a21 1 #ifndef MS5611_H
loopsva 0:f97f410d4a21 2 #define MS5611_H
loopsva 0:f97f410d4a21 3
loopsva 0:f97f410d4a21 4 #include "mbed.h"
loopsva 0:f97f410d4a21 5
loopsva 5:0d7b229474c6 6
loopsva 5:0d7b229474c6 7 #define SEA_PRESS 1013.25 //default sea level pressure level in mb
loopsva 5:0d7b229474c6 8 #define KNOWNALT 327.0 //default known altitude, 5200 Franklin Dr., 94588
loopsva 5:0d7b229474c6 9 #define INHG 0.02952998751 //convert mb to in/Hg constant
loopsva 5:0d7b229474c6 10 #define MB 33.8638815 //convert in/Hg to mb constant
loopsva 5:0d7b229474c6 11 #define FTMETERS 0.3048 //convert feet to meters
loopsva 5:0d7b229474c6 12
loopsva 5:0d7b229474c6 13
loopsva 0:f97f410d4a21 14 /** Software routines to access the Measurement Specialties' MS5611-01BA03
loopsva 0:f97f410d4a21 15 * Variometer Module using the I2C bus option. The MS5611 is a 24 bit
loopsva 0:f97f410d4a21 16 * temperature and pressure transducer for high accuracy Barometer and
loopsva 0:f97f410d4a21 17 * Altimeter applications. It also includes compensation coefficients
loopsva 0:f97f410d4a21 18 * stored within the device.
loopsva 0:f97f410d4a21 19 *
loopsva 0:f97f410d4a21 20 * Code adapted from Measurement Specialties:
loopsva 0:f97f410d4a21 21 * "AN520 C-code example for MS56xx, MS57xx (except analog sensor), and
loopsva 0:f97f410d4a21 22 * MS58xx series pressure sensors"
loopsva 0:f97f410d4a21 23 *
loopsva 0:f97f410d4a21 24 * Note: AN520 has not been updated for use with the MS5611. Changes
loopsva 0:f97f410d4a21 25 * were necessary to "calcPT()" in order to correct scaling of
loopsva 0:f97f410d4a21 26 * pressure readings.
loopsva 0:f97f410d4a21 27 *
loopsva 0:f97f410d4a21 28 * Features:
loopsva 0:f97f410d4a21 29 * Altitude resolution to 10cm
loopsva 0:f97f410d4a21 30 * Fast conversion down to 1 ms
loopsva 0:f97f410d4a21 31 * Low power, 1 μA (standby < 0.15 μA)
loopsva 0:f97f410d4a21 32 * QFN package 5.0 x 3.0 x 1.0 mm^3
loopsva 0:f97f410d4a21 33 * Supply voltage 1.8 to 3.6 V
loopsva 0:f97f410d4a21 34 * Integrated digital pressure sensor (24 bit DeltaSigma ADC)
loopsva 0:f97f410d4a21 35 * Operating range: 10 to 1200 mbar, -40 to +85 °C
loopsva 0:f97f410d4a21 36 * I2C and SPI interface up to 20 MHz
loopsva 0:f97f410d4a21 37 * No external components (Internal oscillator)
loopsva 0:f97f410d4a21 38 * Excellent long term stability
loopsva 0:f97f410d4a21 39 *
loopsva 0:f97f410d4a21 40 * @code
loopsva 0:f97f410d4a21 41 * #include "mbed.h"
loopsva 0:f97f410d4a21 42 * #include "ms5611.h"
loopsva 0:f97f410d4a21 43 *
loopsva 0:f97f410d4a21 44 * ms5611 ms(p9, p10); // i2c pins used
loopsva 0:f97f410d4a21 45 * Serial pc(USBTX, USBRX); // local terminal interface
loopsva 0:f97f410d4a21 46 *
loopsva 0:f97f410d4a21 47 *
loopsva 0:f97f410d4a21 48 * int main (void) {
loopsva 0:f97f410d4a21 49 * pc.baud(921600); // set up USB serial speed
loopsva 0:f97f410d4a21 50 *
loopsva 0:f97f410d4a21 51 * // set up the ms5611
loopsva 0:f97f410d4a21 52 * pc.printf("\n\nInitializing the MS5611..\n");
loopsva 0:f97f410d4a21 53 * ms.cmd_reset();
loopsva 0:f97f410d4a21 54 * pc.printf("Ready\n");
loopsva 0:f97f410d4a21 55 *
loopsva 0:f97f410d4a21 56 * while(1) {
loopsva 6:41c370fa1f7b 57 * double Temp = ms.calcTemp(); //calculate press and temp, then returns current temperature in degC
loopsva 6:41c370fa1f7b 58 * double Press = ms.calcPressure(); //calculate press and temp, then returns current pressure in mb
loopsva 6:41c370fa1f7b 59 * double GetPress = ms.getPressure(); //returns current pressure in mb. Does no calculations. Ususally done after calcTemp()
loopsva 6:41c370fa1f7b 60 * double Altitude = ms.getAltitudeFT(1013.25); //enter pressure at sea level in mb, returns altitude in feet
loopsva 6:41c370fa1f7b 61 * double PressSeaLvlFT = ms.getSeaLevelBaroFT(327.2); //enter known altitude in feet, returns sea level pressure in mb
loopsva 6:41c370fa1f7b 62 * double PressSeaLvlM = ms.getAltitudeFT(99.73); //enter known altitude in meters, returns seal level pressure in mb
loopsva 6:41c370fa1f7b 63 *
loopsva 6:41c370fa1f7b 64 * pc.printf("Temp: %.2f degC\n", Temp);
loopsva 6:41c370fa1f7b 65 * pc.printf("Barometer: %.1f mB %.3f in/Hg\n", Press, Press * 0.0295301);
loopsva 6:41c370fa1f7b 66 * pc.printf("Alt: %.1f ft\n", Altitude);
loopsva 6:41c370fa1f7b 67 * pc.printf("Sea_Lvl: %.1f ft %.2f m\n", PressSeaLvlFT, PressSeaLvlM);
loopsva 0:f97f410d4a21 68 * wait(2.0);
loopsva 0:f97f410d4a21 69 * }
loopsva 0:f97f410d4a21 70 * }
loopsva 0:f97f410d4a21 71 *
loopsva 0:f97f410d4a21 72 * @endcode
loopsva 0:f97f410d4a21 73 */
loopsva 0:f97f410d4a21 74
loopsva 0:f97f410d4a21 75 //_____ M A C R O S
loopsva 0:f97f410d4a21 76
loopsva 0:f97f410d4a21 77 #define MS5611_ADDR_W 0xEE // Module address write mode
loopsva 0:f97f410d4a21 78 #define MS5611_ADDR_R 0xEF // Module address read mode
loopsva 0:f97f410d4a21 79 #define MS5611_CMD_RESET 0x1E // ADC reset command
loopsva 0:f97f410d4a21 80 #define MS5611_CMD_ADC_READ 0x00 // ADC read command
loopsva 0:f97f410d4a21 81 #define MS5611_CMD_ADC_CONV 0x40 // ADC conversion command
loopsva 0:f97f410d4a21 82 #define MS5611_CMD_ADC_D1 0x00 // ADC D1 conversion
loopsva 0:f97f410d4a21 83 #define MS5611_CMD_ADC_D2 0x10 // ADC D2 conversion
loopsva 0:f97f410d4a21 84 #define MS5611_CMD_ADC_256 0x00 // ADC OSR=256
loopsva 0:f97f410d4a21 85 #define MS5611_CMD_ADC_512 0x02 // ADC OSR=512
loopsva 0:f97f410d4a21 86 #define MS5611_CMD_ADC_1024 0x04 // ADC OSR=1024
loopsva 0:f97f410d4a21 87 #define MS5611_CMD_ADC_2048 0x06 // ADC OSR=2048
loopsva 0:f97f410d4a21 88 #define MS5611_CMD_ADC_4096 0x08 // ADC OSR=4096
loopsva 0:f97f410d4a21 89 #define MS5611_CMD_PROM_RD 0xA0 // Prom read command
loopsva 0:f97f410d4a21 90
loopsva 2:05804ed70748 91 /** Create ms5611 controller class
loopsva 2:05804ed70748 92 *
loopsva 2:05804ed70748 93 * @param ms5611 class
loopsva 2:05804ed70748 94 *
loopsva 2:05804ed70748 95 */
loopsva 1:94a46b4fed9d 96 class ms5611 {
loopsva 0:f97f410d4a21 97
loopsva 0:f97f410d4a21 98 public:
loopsva 0:f97f410d4a21 99 /** Create a MS5611 object using the specified I2C object
loopsva 0:f97f410d4a21 100 *
loopsva 0:f97f410d4a21 101 * @param constructor, - the I2C object to communicate with
loopsva 0:f97f410d4a21 102 */
loopsva 0:f97f410d4a21 103 ms5611(PinName sda, PinName scl);
loopsva 0:f97f410d4a21 104 /** Initialize the MS5611 and set up the coefficients
loopsva 0:f97f410d4a21 105 * First - reset the MS5611
loopsva 0:f97f410d4a21 106 * Second - load coefficient values from the MS5611 PROM
loopsva 0:f97f410d4a21 107 * Third - calculate coefficient checksum
loopsva 0:f97f410d4a21 108 * This routine only needs to be run once at boot up
loopsva 0:f97f410d4a21 109 *
loopsva 0:f97f410d4a21 110 * @param NONE
loopsva 0:f97f410d4a21 111 */
loopsva 0:f97f410d4a21 112 void cmd_reset();
loopsva 0:f97f410d4a21 113 /** Calculate and return compensated temperature
loopsva 0:f97f410d4a21 114 * Returns double temperature in degC
loopsva 0:f97f410d4a21 115 *
loopsva 0:f97f410d4a21 116 * @param NONE
loopsva 0:f97f410d4a21 117 */
loopsva 0:f97f410d4a21 118 double calcTemp();
loopsva 0:f97f410d4a21 119 /** Calculate and return compensated barometric pressure
loopsva 0:f97f410d4a21 120 * Returns double pressure in millibars
loopsva 0:f97f410d4a21 121 *
loopsva 0:f97f410d4a21 122 * @param NONE
loopsva 0:f97f410d4a21 123 */
loopsva 0:f97f410d4a21 124 double calcPressure();
loopsva 3:c2d1b0d432ad 125 /** Return compensated barometric pressure
loopsva 3:c2d1b0d432ad 126 * Returns double pressure in millibars
loopsva 3:c2d1b0d432ad 127 * DOES NOT RE-CALCULATE FIRST!!!
loopsva 3:c2d1b0d432ad 128 * Saves time if you calcTemp(); first
loopsva 3:c2d1b0d432ad 129 *
loopsva 3:c2d1b0d432ad 130 * @param NONE
loopsva 3:c2d1b0d432ad 131 */
loopsva 3:c2d1b0d432ad 132 double getPressure();
loopsva 3:c2d1b0d432ad 133 /** Calculate and returns altitude in feet
loopsva 5:0d7b229474c6 134 * Returns float altitude in feet
loopsva 3:c2d1b0d432ad 135 *
loopsva 5:0d7b229474c6 136 * @param float known pressure (mB) at sea level
loopsva 3:c2d1b0d432ad 137 */
loopsva 3:c2d1b0d432ad 138 float getAltitudeFT(float sea_pressure);
loopsva 5:0d7b229474c6 139 /** Calculate and returns sea level baro
loopsva 5:0d7b229474c6 140 * Returns float seal level barometer in feet
loopsva 5:0d7b229474c6 141 *
loopsva 5:0d7b229474c6 142 * @param float known altitude in feet
loopsva 5:0d7b229474c6 143 */
loopsva 5:0d7b229474c6 144 float getSeaLevelBaroFT(float known_alt);
loopsva 5:0d7b229474c6 145 /** Calculate and returns sea level baro
loopsva 5:0d7b229474c6 146 * Returns float seal level barometer in meters
loopsva 5:0d7b229474c6 147 *
loopsva 5:0d7b229474c6 148 * @param float known altitude in meters
loopsva 5:0d7b229474c6 149 */
loopsva 5:0d7b229474c6 150 float getSeaLevelBaroM(float known_alt);
loopsva 0:f97f410d4a21 151
loopsva 0:f97f410d4a21 152 private:
loopsva 0:f97f410d4a21 153 int m_i2c_start(bool readMode);
loopsva 0:f97f410d4a21 154 void m_i2c_stop(void);
loopsva 0:f97f410d4a21 155 unsigned char m_i2c_write(unsigned char data);
loopsva 0:f97f410d4a21 156 unsigned char m_i2c_readAck(void);
loopsva 0:f97f410d4a21 157 unsigned char m_i2c_readNak(void);
loopsva 0:f97f410d4a21 158 void m_i2c_send(char cmd);
loopsva 0:f97f410d4a21 159 void loadCoefs();
loopsva 0:f97f410d4a21 160 unsigned long cmd_adc(char cmd);
loopsva 0:f97f410d4a21 161 unsigned int cmd_prom(char coef_num);
loopsva 2:05804ed70748 162 unsigned char crc4(unsigned n_prom[]);
loopsva 0:f97f410d4a21 163 void calcPT();
loopsva 0:f97f410d4a21 164 unsigned int PTbuffer[8]; // calibration coefficients
loopsva 0:f97f410d4a21 165
loopsva 0:f97f410d4a21 166 protected:
loopsva 0:f97f410d4a21 167 I2C _i2c;
loopsva 0:f97f410d4a21 168
loopsva 0:f97f410d4a21 169
loopsva 0:f97f410d4a21 170 };
loopsva 0:f97f410d4a21 171 #endif