UAVRO / ms5611

High resolution barometer and altimeter using i2c mode

Dependents:   Q2_Stabi

Fork of ms5611 by Kevin Braun

ms5611.h@7:90ee2168baa7, 2014-12-22 (annotated)

Committer:
loopsva
Date:
Mon Dec 22 23:38:34 2014 +0000
Revision:
7:90ee2168baa7
Parent:
6:41c370fa1f7b
Child:
8:461f68bc94f2
Added second constructor so user can choose the polarity of the ms5611's CSB pin.

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 7:90ee2168baa7 44 * //ms5611 ms(p9, p10); // i2c pins used
loopsva 7:90ee2168baa7 45 * ms5611 ms(p9, p10, ms5611::CSBpin_0); // NEW!! with rev 7. User can set polarity of CSB pin
loopsva 7:90ee2168baa7 46 * //ms5611 ms(p9, p10, ms5611::CSBpin_1);
loopsva 7:90ee2168baa7 47 *
loopsva 0:f97f410d4a21 48 * Serial pc(USBTX, USBRX); // local terminal interface
loopsva 0:f97f410d4a21 49 *
loopsva 0:f97f410d4a21 50 *
loopsva 0:f97f410d4a21 51 * int main (void) {
loopsva 0:f97f410d4a21 52 * pc.baud(921600); // set up USB serial speed
loopsva 0:f97f410d4a21 53 *
loopsva 0:f97f410d4a21 54 * // set up the ms5611
loopsva 0:f97f410d4a21 55 * pc.printf("\n\nInitializing the MS5611..\n");
loopsva 0:f97f410d4a21 56 * ms.cmd_reset();
loopsva 0:f97f410d4a21 57 * pc.printf("Ready\n");
loopsva 0:f97f410d4a21 58 *
loopsva 0:f97f410d4a21 59 * while(1) {
loopsva 6:41c370fa1f7b 60 * double Temp = ms.calcTemp(); //calculate press and temp, then returns current temperature in degC
loopsva 6:41c370fa1f7b 61 * double Press = ms.calcPressure(); //calculate press and temp, then returns current pressure in mb
loopsva 6:41c370fa1f7b 62 * double GetPress = ms.getPressure(); //returns current pressure in mb. Does no calculations. Ususally done after calcTemp()
loopsva 6:41c370fa1f7b 63 * double Altitude = ms.getAltitudeFT(1013.25); //enter pressure at sea level in mb, returns altitude in feet
loopsva 6:41c370fa1f7b 64 * double PressSeaLvlFT = ms.getSeaLevelBaroFT(327.2); //enter known altitude in feet, returns sea level pressure in mb
loopsva 6:41c370fa1f7b 65 * double PressSeaLvlM = ms.getAltitudeFT(99.73); //enter known altitude in meters, returns seal level pressure in mb
loopsva 6:41c370fa1f7b 66 *
loopsva 6:41c370fa1f7b 67 * pc.printf("Temp: %.2f degC\n", Temp);
loopsva 6:41c370fa1f7b 68 * pc.printf("Barometer: %.1f mB %.3f in/Hg\n", Press, Press * 0.0295301);
loopsva 6:41c370fa1f7b 69 * pc.printf("Alt: %.1f ft\n", Altitude);
loopsva 6:41c370fa1f7b 70 * pc.printf("Sea_Lvl: %.1f ft %.2f m\n", PressSeaLvlFT, PressSeaLvlM);
loopsva 0:f97f410d4a21 71 * wait(2.0);
loopsva 0:f97f410d4a21 72 * }
loopsva 0:f97f410d4a21 73 * }
loopsva 0:f97f410d4a21 74 *
loopsva 0:f97f410d4a21 75 * @endcode
loopsva 0:f97f410d4a21 76 */
loopsva 0:f97f410d4a21 77
loopsva 0:f97f410d4a21 78 //_____ M A C R O S
loopsva 0:f97f410d4a21 79
loopsva 7:90ee2168baa7 80 #define MS5611_ADDR_W 0xEE // Module address write mode (CSBpin = 0);
loopsva 0:f97f410d4a21 81 #define MS5611_ADDR_R 0xEF // Module address read mode
loopsva 0:f97f410d4a21 82 #define MS5611_CMD_RESET 0x1E // ADC reset command
loopsva 0:f97f410d4a21 83 #define MS5611_CMD_ADC_READ 0x00 // ADC read command
loopsva 0:f97f410d4a21 84 #define MS5611_CMD_ADC_CONV 0x40 // ADC conversion command
loopsva 0:f97f410d4a21 85 #define MS5611_CMD_ADC_D1 0x00 // ADC D1 conversion
loopsva 0:f97f410d4a21 86 #define MS5611_CMD_ADC_D2 0x10 // ADC D2 conversion
loopsva 0:f97f410d4a21 87 #define MS5611_CMD_ADC_256 0x00 // ADC OSR=256
loopsva 0:f97f410d4a21 88 #define MS5611_CMD_ADC_512 0x02 // ADC OSR=512
loopsva 0:f97f410d4a21 89 #define MS5611_CMD_ADC_1024 0x04 // ADC OSR=1024
loopsva 0:f97f410d4a21 90 #define MS5611_CMD_ADC_2048 0x06 // ADC OSR=2048
loopsva 0:f97f410d4a21 91 #define MS5611_CMD_ADC_4096 0x08 // ADC OSR=4096
loopsva 0:f97f410d4a21 92 #define MS5611_CMD_PROM_RD 0xA0 // Prom read command
loopsva 0:f97f410d4a21 93
loopsva 2:05804ed70748 94 /** Create ms5611 controller class
loopsva 2:05804ed70748 95 *
loopsva 2:05804ed70748 96 * @param ms5611 class
loopsva 2:05804ed70748 97 *
loopsva 2:05804ed70748 98 */
loopsva 1:94a46b4fed9d 99 class ms5611 {
loopsva 0:f97f410d4a21 100
loopsva 0:f97f410d4a21 101 public:
loopsva 7:90ee2168baa7 102 enum CSBpolarity {
loopsva 7:90ee2168baa7 103 CSBpin_0, //CSB pin is grounded, I2C address is 0xEE and 0xEF
loopsva 7:90ee2168baa7 104 CSBpin_1, //CSB pin is tied to Vdd, I2C address is 0xEC and 0xED
loopsva 7:90ee2168baa7 105 };
loopsva 0:f97f410d4a21 106 /** Create a MS5611 object using the specified I2C object
loopsva 7:90ee2168baa7 107 * - User fixed I2C address 0xEE, CSB pin = 0
loopsva 7:90ee2168baa7 108 * - This is the default legacy constructor
loopsva 7:90ee2168baa7 109 * @param sda - mbed I2C interface pin
loopsva 7:90ee2168baa7 110 * @param scl - mbed I2C interface pin
loopsva 0:f97f410d4a21 111 */
loopsva 0:f97f410d4a21 112 ms5611(PinName sda, PinName scl);
loopsva 7:90ee2168baa7 113 /** Create a MS5611 object using the specified I2C object
loopsva 7:90ee2168baa7 114 * - User defined use of the CSB pin
loopsva 7:90ee2168baa7 115 * - CSB pin = 0, user set I2C address to 0xEE
loopsva 7:90ee2168baa7 116 * - CSB pin = 1, user set I2C address to 0xEC
loopsva 7:90ee2168baa7 117 * @param sda - mbed I2C interface pin
loopsva 7:90ee2168baa7 118 * @param scl - mbed I2C interface pin
loopsva 7:90ee2168baa7 119 * @param ms5611::CSBpin_0 - CSB pin tied to ground
loopsva 7:90ee2168baa7 120 * @param ms5611::CSBpin_1 - CSB pin tied to VDD
loopsva 7:90ee2168baa7 121 */
loopsva 7:90ee2168baa7 122 ms5611(PinName sda, PinName scl, CSBpolarity CSBpin);
loopsva 0:f97f410d4a21 123 /** Initialize the MS5611 and set up the coefficients
loopsva 0:f97f410d4a21 124 * First - reset the MS5611
loopsva 0:f97f410d4a21 125 * Second - load coefficient values from the MS5611 PROM
loopsva 0:f97f410d4a21 126 * Third - calculate coefficient checksum
loopsva 0:f97f410d4a21 127 * This routine only needs to be run once at boot up
loopsva 0:f97f410d4a21 128 *
loopsva 0:f97f410d4a21 129 * @param NONE
loopsva 0:f97f410d4a21 130 */
loopsva 0:f97f410d4a21 131 void cmd_reset();
loopsva 0:f97f410d4a21 132 /** Calculate and return compensated temperature
loopsva 0:f97f410d4a21 133 * Returns double temperature in degC
loopsva 0:f97f410d4a21 134 *
loopsva 0:f97f410d4a21 135 * @param NONE
loopsva 0:f97f410d4a21 136 */
loopsva 0:f97f410d4a21 137 double calcTemp();
loopsva 0:f97f410d4a21 138 /** Calculate and return compensated barometric pressure
loopsva 0:f97f410d4a21 139 * Returns double pressure in millibars
loopsva 0:f97f410d4a21 140 *
loopsva 0:f97f410d4a21 141 * @param NONE
loopsva 0:f97f410d4a21 142 */
loopsva 0:f97f410d4a21 143 double calcPressure();
loopsva 3:c2d1b0d432ad 144 /** Return compensated barometric pressure
loopsva 3:c2d1b0d432ad 145 * Returns double pressure in millibars
loopsva 3:c2d1b0d432ad 146 * DOES NOT RE-CALCULATE FIRST!!!
loopsva 3:c2d1b0d432ad 147 * Saves time if you calcTemp(); first
loopsva 3:c2d1b0d432ad 148 *
loopsva 3:c2d1b0d432ad 149 * @param NONE
loopsva 3:c2d1b0d432ad 150 */
loopsva 3:c2d1b0d432ad 151 double getPressure();
loopsva 3:c2d1b0d432ad 152 /** Calculate and returns altitude in feet
loopsva 5:0d7b229474c6 153 * Returns float altitude in feet
loopsva 3:c2d1b0d432ad 154 *
loopsva 5:0d7b229474c6 155 * @param float known pressure (mB) at sea level
loopsva 3:c2d1b0d432ad 156 */
loopsva 3:c2d1b0d432ad 157 float getAltitudeFT(float sea_pressure);
loopsva 5:0d7b229474c6 158 /** Calculate and returns sea level baro
loopsva 5:0d7b229474c6 159 * Returns float seal level barometer in feet
loopsva 5:0d7b229474c6 160 *
loopsva 5:0d7b229474c6 161 * @param float known altitude in feet
loopsva 5:0d7b229474c6 162 */
loopsva 5:0d7b229474c6 163 float getSeaLevelBaroFT(float known_alt);
loopsva 5:0d7b229474c6 164 /** Calculate and returns sea level baro
loopsva 5:0d7b229474c6 165 * Returns float seal level barometer in meters
loopsva 5:0d7b229474c6 166 *
loopsva 5:0d7b229474c6 167 * @param float known altitude in meters
loopsva 5:0d7b229474c6 168 */
loopsva 5:0d7b229474c6 169 float getSeaLevelBaroM(float known_alt);
loopsva 0:f97f410d4a21 170
loopsva 0:f97f410d4a21 171 private:
loopsva 7:90ee2168baa7 172 char _i2cWAddr;
loopsva 7:90ee2168baa7 173 char _i2cRAddr;
loopsva 0:f97f410d4a21 174 int m_i2c_start(bool readMode);
loopsva 0:f97f410d4a21 175 void m_i2c_stop(void);
loopsva 0:f97f410d4a21 176 unsigned char m_i2c_write(unsigned char data);
loopsva 0:f97f410d4a21 177 unsigned char m_i2c_readAck(void);
loopsva 0:f97f410d4a21 178 unsigned char m_i2c_readNak(void);
loopsva 0:f97f410d4a21 179 void m_i2c_send(char cmd);
loopsva 0:f97f410d4a21 180 void loadCoefs();
loopsva 0:f97f410d4a21 181 unsigned long cmd_adc(char cmd);
loopsva 0:f97f410d4a21 182 unsigned int cmd_prom(char coef_num);
loopsva 2:05804ed70748 183 unsigned char crc4(unsigned n_prom[]);
loopsva 0:f97f410d4a21 184 void calcPT();
loopsva 0:f97f410d4a21 185 unsigned int PTbuffer[8]; // calibration coefficients
loopsva 0:f97f410d4a21 186
loopsva 0:f97f410d4a21 187 protected:
loopsva 0:f97f410d4a21 188 I2C _i2c;
loopsva 0:f97f410d4a21 189
loopsva 0:f97f410d4a21 190
loopsva 0:f97f410d4a21 191 };
loopsva 0:f97f410d4a21 192 #endif