Flying Sea Glider / MS5837

mini glider FSG

Fork of MS5837 by POTLESS

MS5837.cpp@0:5f6034409fd0, 2017-05-28 (annotated)

Committer:
potless
Date:
Sun May 28 10:29:51 2017 +0000
Revision:
0:5f6034409fd0
Child:
1:a8eea2a2263f
lib nouveau capteur pression ARNSRS ALFA

Who changed what in which revision?

UserRevisionLine numberNew contents of line
potless 0:5f6034409fd0 1 #include <stdlib.h>
potless 0:5f6034409fd0 2 #include "MS5837.h"
potless 0:5f6034409fd0 3
potless 0:5f6034409fd0 4
potless 0:5f6034409fd0 5 /*
potless 0:5f6034409fd0 6 * Sensor operating function according data sheet
potless 0:5f6034409fd0 7 */
potless 0:5f6034409fd0 8
potless 0:5f6034409fd0 9 void MS5837::MS5837Init(void)
potless 0:5f6034409fd0 10 {
potless 0:5f6034409fd0 11 MS5837Reset();
potless 0:5f6034409fd0 12 MS5837ReadProm();
potless 0:5f6034409fd0 13 return;
potless 0:5f6034409fd0 14 }
potless 0:5f6034409fd0 15
potless 0:5f6034409fd0 16 /* Send soft reset to the sensor */
potless 0:5f6034409fd0 17 void MS5837::MS5837Reset(void)
potless 0:5f6034409fd0 18 {
potless 0:5f6034409fd0 19 /* transmit out 1 byte reset command */
potless 0:5f6034409fd0 20 ms5837_tx_data[0] = ms5837_reset;
potless 0:5f6034409fd0 21 if ( i2c.write( device_address, ms5837_tx_data, 1 ) );
potless 0:5f6034409fd0 22 printf("send soft reset\n");
potless 0:5f6034409fd0 23 wait_ms(20);
potless 0:5f6034409fd0 24 }
potless 0:5f6034409fd0 25
potless 0:5f6034409fd0 26 /* read the sensor calibration data from rom */
potless 0:5f6034409fd0 27 void MS5837::MS5837ReadProm(void)
potless 0:5f6034409fd0 28 {
potless 0:5f6034409fd0 29 uint8_t i,j;
potless 0:5f6034409fd0 30 for (i=0; i<8; i++) {
potless 0:5f6034409fd0 31 j = i;
potless 0:5f6034409fd0 32 ms5837_tx_data[0] = ms5837_PROMread + (j<<1);
potless 0:5f6034409fd0 33 if ( i2c.write( device_address, ms5837_tx_data, 1 ) );
potless 0:5f6034409fd0 34 if ( i2c.read( device_address, ms5837_rx_data, 2 ) );
potless 0:5f6034409fd0 35 C[i] = ms5837_rx_data[1] + (ms5837_rx_data[0]<<8);
potless 0:5f6034409fd0 36 }
potless 0:5f6034409fd0 37 }
potless 0:5f6034409fd0 38
potless 0:5f6034409fd0 39 /* Start the sensor pressure conversion */
potless 0:5f6034409fd0 40 void MS5837::MS5837ConvertD1(void)
potless 0:5f6034409fd0 41 {
potless 0:5f6034409fd0 42 ms5837_tx_data[0] = ms5837_convD1;
potless 0:5f6034409fd0 43 if ( i2c.write( device_address, ms5837_tx_data, 1 ) );
potless 0:5f6034409fd0 44 }
potless 0:5f6034409fd0 45
potless 0:5f6034409fd0 46 /* Start the sensor temperature conversion */
potless 0:5f6034409fd0 47 void MS5837:: MS5837ConvertD2(void)
potless 0:5f6034409fd0 48 {
potless 0:5f6034409fd0 49 ms5837_tx_data[0] = ms5837_convD2;
potless 0:5f6034409fd0 50 if ( i2c.write( device_address, ms5837_tx_data, 1 ) );
potless 0:5f6034409fd0 51 }
potless 0:5f6034409fd0 52
potless 0:5f6034409fd0 53 /* Read the previous started conversion results */
potless 0:5f6034409fd0 54 int32_t MS5837::MS5837ReadADC(void)
potless 0:5f6034409fd0 55 {
potless 0:5f6034409fd0 56 int32_t adc;
potless 0:5f6034409fd0 57 wait_ms(150);
potless 0:5f6034409fd0 58 ms5837_tx_data[0] = ms5837_ADCread;
potless 0:5f6034409fd0 59 if ( i2c.write( device_address, ms5837_tx_data, 1 ) );
potless 0:5f6034409fd0 60 if ( i2c.read( device_address, ms5837_rx_data, 3 ) );
potless 0:5f6034409fd0 61 adc = ms5837_rx_data[2] + (ms5837_rx_data[1]<<8) + (ms5837_rx_data[0]<<16);
potless 0:5f6034409fd0 62 //printf("ADC value: %x\n", adc);
potless 0:5f6034409fd0 63 return (adc);
potless 0:5f6034409fd0 64 }
potless 0:5f6034409fd0 65
potless 0:5f6034409fd0 66 /* return the results */
potless 0:5f6034409fd0 67 float MS5837::MS5837_Pressure (void)
potless 0:5f6034409fd0 68 {
potless 0:5f6034409fd0 69 return P_MS5837;
potless 0:5f6034409fd0 70 }
potless 0:5f6034409fd0 71 float MS5837::MS5837_Temperature (void)
potless 0:5f6034409fd0 72 {
potless 0:5f6034409fd0 73 return T_MS5837;
potless 0:5f6034409fd0 74 }
potless 0:5f6034409fd0 75
potless 0:5f6034409fd0 76 /* Sensor reading and calculation procedure */
potless 0:5f6034409fd0 77 void MS5837::Barometer_MS5837(void)
potless 0:5f6034409fd0 78 {
potless 0:5f6034409fd0 79 int32_t dT, temp;
potless 0:5f6034409fd0 80 int64_t OFF, SENS, press;
potless 0:5f6034409fd0 81
potless 0:5f6034409fd0 82 //no need to do this everytime!
potless 0:5f6034409fd0 83
potless 0:5f6034409fd0 84
potless 0:5f6034409fd0 85 MS5837ConvertD1(); // start pressure conversion
potless 0:5f6034409fd0 86 D1 = MS5837ReadADC(); // read the pressure value
potless 0:5f6034409fd0 87 MS5837ConvertD2(); // start temperature conversion
potless 0:5f6034409fd0 88 D2 = MS5837ReadADC(); // read the temperature value
potless 0:5f6034409fd0 89 //printf("D1 = %d\n", D1);
potless 0:5f6034409fd0 90 /* calculation according MS5837-01BA data sheet DA5837-01BA_006 */
potless 0:5f6034409fd0 91 dT = D2 - (C[5]* 256);
potless 0:5f6034409fd0 92 OFF = (int64_t)C[2] * (1<<16) + ((int64_t)dT * (int64_t)C[4]) / (1<<7);
potless 0:5f6034409fd0 93 SENS = (int64_t)C[1] * (1<<15) + ((int64_t)dT * (int64_t)C[3]) / (1<<8);
potless 0:5f6034409fd0 94
potless 0:5f6034409fd0 95 temp = 2000 + (dT * C[6]) / (1<<23);
potless 0:5f6034409fd0 96 T_MS5837 = (float) temp / 100.0f; // result of temperature in deg C in this var
potless 0:5f6034409fd0 97 press = (((int64_t)D1 * SENS) / (1<<21) - OFF) / (1<<13);
potless 0:5f6034409fd0 98 P_MS5837 = (float) press / 10.0f; // result of pressure in mBar in this var
potless 0:5f6034409fd0 99
potless 0:5f6034409fd0 100 if (P_MS5837 < 900 || P_MS5837 > 3000) {
potless 0:5f6034409fd0 101 MS5837Reset(); // reset the sensor
potless 0:5f6034409fd0 102 MS5837ReadProm(); // read the calibration values
potless 0:5f6034409fd0 103 }
potless 0:5f6034409fd0 104 }
potless 0:5f6034409fd0 105
potless 0:5f6034409fd0 106 float MS5837::depth(void) {
potless 0:5f6034409fd0 107 return (P_MS5837/100)*1.019716;
potless 0:5f6034409fd0 108 }