Diff: ms5561.h

Revision:

7:2e8bc98f3dda

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/ms5561.h	Tue May 20 16:13:09 2014 +0000
@@ -0,0 +1,171 @@
+#ifndef MS5561H
+#define MS5561_H
+
+#include "mbed.h"
+
+
+#define SEA_PRESS   1013.25                 //default sea level pressure level in mb
+#define KNOWNALT    327.0                   //default known altitude, 5200 Franklin Dr., 94588
+#define INHG        0.02952998751           //convert mb to in/Hg constant
+#define MB          33.8638815              //convert in/Hg to mb constant
+#define FTMETERS    0.3048                  //convert feet to meters
+
+
+/** Software routines to access the Measurement Specialties' MS5611-01BA03 
+ *  Variometer Module using the I2C bus option.  The MS5611 is a 24 bit 
+ *  temperature and pressure transducer for high accuracy Barometer and 
+ *  Altimeter applications.  It also includes compensation coefficients
+ *  stored within the device. 
+ * 
+ *  Code adapted from Measurement Specialties:
+ *  "AN520 C-code example for MS56xx, MS57xx (except analog sensor), and 
+ *  MS58xx series pressure sensors"
+ *
+ *  Note: AN520 has not been updated for use with the MS5611.  Changes
+ *  were necessary to "calcPT()" in order to correct scaling of 
+ *  pressure readings.
+ * 
+ *  Features:
+ *          Altitude resolution to 10cm
+ *          Fast conversion down to 1 ms
+ *          Low power, 1 μA (standby < 0.15 μA)
+ *          QFN package 5.0 x 3.0 x 1.0 mm^3
+ *          Supply voltage 1.8 to 3.6 V
+ *          Integrated digital pressure sensor (24 bit DeltaSigma ADC)
+ *          Operating range: 10 to 1200 mbar, -40 to +85 °C
+ *          I2C and SPI interface up to 20 MHz
+ *          No external components (Internal oscillator)
+ *          Excellent long term stability
+ *
+ * @code
+ * #include "mbed.h"
+ * #include "ms5611.h" 
+ *
+ * ms5611 ms(p9, p10);                        // i2c pins used
+ * Serial pc(USBTX, USBRX);                   // local terminal interface
+ *
+ *
+ * int main (void) {
+ *     pc.baud(921600);                        // set up USB serial speed
+ *
+ *     // set up the ms5611
+ *     pc.printf("\n\nInitializing the MS5611..\n");
+ *     ms.cmd_reset();
+ *     pc.printf("Ready\n");
+ *
+ *     while(1) {
+ *         double Temp = ms.calcTemp();                         //calculate press and temp, then returns current temperature in degC
+ *         double Press = ms.calcPressure();                    //calculate press and temp, then returns current pressure in mb
+ *         double GetPress = ms.getPressure();                  //returns current pressure in mb. Does no calculations.  Ususally done after calcTemp()
+ *         double Altitude = ms.getAltitudeFT(1013.25);         //enter pressure at sea level in mb, returns altitude in feet
+ *         double PressSeaLvlFT = ms.getSeaLevelBaroFT(327.2);  //enter known altitude in feet, returns sea level pressure in mb
+ *         double PressSeaLvlM = ms.getAltitudeFT(99.73);       //enter known altitude in meters, returns seal level pressure in mb
+ *
+ *         pc.printf("Temp: %.2f degC\n", Temp);    
+ *         pc.printf("Barometer: %.1f mB  %.3f in/Hg\n", Press, Press * 0.0295301);
+ *         pc.printf("Alt: %.1f ft\n", Altitude);
+ *         pc.printf("Sea_Lvl: %.1f ft   %.2f m\n", PressSeaLvlFT, PressSeaLvlM);
+ *         wait(2.0);
+ *     }
+ * }
+ *
+ * @endcode
+ */
+ 
+//_____ M A C R O S
+
+#define MS5611_ADDR_W 0xEC // Module address write mode CHANGED FOR 5561 ORIGINAL 0Xee
+#define MS5611_ADDR_R 0xED // Module address read modeCHANGED FOR 5561 ORIGINAL 0XeF
+#define MS5611_CMD_RESET 0x1E // ADC reset command
+#define MS5611_CMD_ADC_READ 0x00 // ADC read command
+#define MS5611_CMD_ADC_CONV 0x40 // ADC conversion command
+#define MS5611_CMD_ADC_D1 0x00 // ADC D1 conversion
+#define MS5611_CMD_ADC_D2 0x10 // ADC D2 conversion
+#define MS5611_CMD_ADC_256 0x00 // ADC OSR=256
+#define MS5611_CMD_ADC_512 0x02 // ADC OSR=512
+#define MS5611_CMD_ADC_1024 0x04 // ADC OSR=1024
+#define MS5611_CMD_ADC_2048 0x06 // ADC OSR=2048
+#define MS5611_CMD_ADC_4096 0x08 // ADC OSR=4096
+#define MS5611_CMD_PROM_RD 0xA0 // Prom read command
+
+    /** Create ms5611 controller class
+     *
+     * @param ms5611 class
+     *
+     */
+class ms5611 {
+
+public:
+    /** Create a MS5611 object using the specified I2C object
+     *
+     * @param constructor, - the I2C object to communicate with
+     */
+    ms5611(PinName sda, PinName scl);
+    /** Initialize the MS5611 and set up the coefficients
+     *    First - reset the MS5611
+     *    Second - load coefficient values from the MS5611 PROM
+     *    Third  - calculate coefficient checksum
+     *  This routine only needs to be run once at boot up
+     *
+     * @param NONE
+     */
+    void cmd_reset();
+    /** Calculate and return compensated temperature
+     *    Returns double temperature in degC
+     *
+     * @param NONE
+     */
+    double calcTemp();
+    /** Calculate and return compensated barometric pressure
+     *    Returns double pressure in millibars
+     *
+     * @param NONE
+     */
+    double calcPressure();
+    /** Return compensated barometric pressure
+     *    Returns double pressure in millibars
+     *    DOES NOT RE-CALCULATE FIRST!!!
+     *    Saves time if you calcTemp(); first
+     *
+     * @param NONE
+     */
+    double getPressure();
+    /** Calculate and returns altitude in feet
+     *    Returns float altitude in feet
+     *
+     * @param float known pressure (mB) at sea level
+     */
+    float getAltitudeFT(float sea_pressure);
+    /** Calculate and returns sea level baro
+     *    Returns float seal level barometer in feet
+     *
+     * @param float known altitude in feet
+     */
+    float getSeaLevelBaroFT(float known_alt);
+    /** Calculate and returns sea level baro
+     *    Returns float seal level barometer in meters
+     *
+     * @param float known altitude in meters
+     */
+    float getSeaLevelBaroM(float known_alt);
+    
+private:
+    int m_i2c_start(bool readMode);
+    void m_i2c_stop(void);
+    unsigned char m_i2c_write(unsigned char data);
+    unsigned char m_i2c_readAck(void);
+    unsigned char m_i2c_readNak(void);
+    void m_i2c_send(char cmd);
+    void loadCoefs();
+    unsigned long cmd_adc(char cmd);
+    unsigned int cmd_prom(char coef_num);
+    unsigned char crc4(unsigned  n_prom[]);
+    void calcPT();
+    unsigned int PTbuffer[8];       // calibration coefficients
+  
+protected:
+    I2C     _i2c;
+    
+
+}; 
+#endif