mini glider FSG
Fork of MS5837 by
Diff: MS5837.cpp
- Revision:
- 0:5f6034409fd0
- Child:
- 1:a8eea2a2263f
diff -r 000000000000 -r 5f6034409fd0 MS5837.cpp --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/MS5837.cpp Sun May 28 10:29:51 2017 +0000 @@ -0,0 +1,108 @@ +#include <stdlib.h> +#include "MS5837.h" + + +/* + * Sensor operating function according data sheet + */ + +void MS5837::MS5837Init(void) +{ + MS5837Reset(); + MS5837ReadProm(); + return; +} + +/* Send soft reset to the sensor */ +void MS5837::MS5837Reset(void) +{ + /* transmit out 1 byte reset command */ + ms5837_tx_data[0] = ms5837_reset; + if ( i2c.write( device_address, ms5837_tx_data, 1 ) ); + printf("send soft reset\n"); + wait_ms(20); +} + +/* read the sensor calibration data from rom */ +void MS5837::MS5837ReadProm(void) +{ + uint8_t i,j; + for (i=0; i<8; i++) { + j = i; + ms5837_tx_data[0] = ms5837_PROMread + (j<<1); + if ( i2c.write( device_address, ms5837_tx_data, 1 ) ); + if ( i2c.read( device_address, ms5837_rx_data, 2 ) ); + C[i] = ms5837_rx_data[1] + (ms5837_rx_data[0]<<8); + } +} + +/* Start the sensor pressure conversion */ +void MS5837::MS5837ConvertD1(void) +{ + ms5837_tx_data[0] = ms5837_convD1; + if ( i2c.write( device_address, ms5837_tx_data, 1 ) ); +} + +/* Start the sensor temperature conversion */ +void MS5837:: MS5837ConvertD2(void) +{ + ms5837_tx_data[0] = ms5837_convD2; + if ( i2c.write( device_address, ms5837_tx_data, 1 ) ); +} + +/* Read the previous started conversion results */ +int32_t MS5837::MS5837ReadADC(void) +{ + int32_t adc; + wait_ms(150); + ms5837_tx_data[0] = ms5837_ADCread; + if ( i2c.write( device_address, ms5837_tx_data, 1 ) ); + if ( i2c.read( device_address, ms5837_rx_data, 3 ) ); + adc = ms5837_rx_data[2] + (ms5837_rx_data[1]<<8) + (ms5837_rx_data[0]<<16); + //printf("ADC value: %x\n", adc); + return (adc); +} + +/* return the results */ +float MS5837::MS5837_Pressure (void) +{ + return P_MS5837; +} +float MS5837::MS5837_Temperature (void) +{ + return T_MS5837; +} + +/* Sensor reading and calculation procedure */ +void MS5837::Barometer_MS5837(void) +{ + int32_t dT, temp; + int64_t OFF, SENS, press; + + //no need to do this everytime! + + + MS5837ConvertD1(); // start pressure conversion + D1 = MS5837ReadADC(); // read the pressure value + MS5837ConvertD2(); // start temperature conversion + D2 = MS5837ReadADC(); // read the temperature value + //printf("D1 = %d\n", D1); + /* calculation according MS5837-01BA data sheet DA5837-01BA_006 */ + dT = D2 - (C[5]* 256); + OFF = (int64_t)C[2] * (1<<16) + ((int64_t)dT * (int64_t)C[4]) / (1<<7); + SENS = (int64_t)C[1] * (1<<15) + ((int64_t)dT * (int64_t)C[3]) / (1<<8); + + temp = 2000 + (dT * C[6]) / (1<<23); + T_MS5837 = (float) temp / 100.0f; // result of temperature in deg C in this var + press = (((int64_t)D1 * SENS) / (1<<21) - OFF) / (1<<13); + P_MS5837 = (float) press / 10.0f; // result of pressure in mBar in this var + + if (P_MS5837 < 900 || P_MS5837 > 3000) { + MS5837Reset(); // reset the sensor + MS5837ReadProm(); // read the calibration values + } +} + +float MS5837::depth(void) { + return (P_MS5837/100)*1.019716; +} \ No newline at end of file