Updated
Revision 0:68909f7f98bc, committed 2019-01-05
- Comitter:
- Swabey89
- Date:
- Sat Jan 05 15:03:12 2019 +0000
- Commit message:
- Updated
Changed in this revision
BMP280.cpp | Show annotated file Show diff for this revision Revisions of this file |
BMP280.h | Show annotated file Show diff for this revision Revisions of this file |
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/BMP280.cpp Sat Jan 05 15:03:12 2019 +0000 @@ -0,0 +1,171 @@ +/** + * BMP280 Combined humidity and pressure sensor library + * + * @author Toyomasa Watarai + * @version 1.0 + * @date 06-April-2015 + * + * bugfixing by charly + * + * Library for "BMP280 temperature, humidity and pressure sensor module" from Switch Science + * https://www.switch-science.com/catalog/2236/ + * + * For more information about the BMP280: + * http://ae-bst.resource.bosch.com/media/products/dokumente/BMP280/BST-BMP280_DS001-10.pdf + */ + +#include "mbed.h" +#include "BMP280.h" + +BMP280::BMP280(PinName sda, PinName scl, char slave_adr) + : + i2c_p(new I2C(sda, scl)), + i2c(*i2c_p), + address(slave_adr<<1), + t_fine(0) +{ + initialize(); +} + +BMP280::BMP280(I2C &i2c_obj, char slave_adr) + : + i2c_p(NULL), + i2c(i2c_obj), + address(slave_adr<<1), + t_fine(0) +{ + initialize(); +} + +BMP280::~BMP280() +{ + if (NULL != i2c_p) + delete i2c_p; +} + +void BMP280::initialize() +{ + char cmd[18]; + + //cmd[0] = 0xf2; // ctrl_hum + //cmd[1] = 0x01; // Humidity oversampling x1 + //i2c.write(address, cmd, 2); + + cmd[0] = 0xf4; // ctrl_meas + //cmd[1] = 0x27; // Temparature oversampling x1, Pressure oversampling x1, Normal mode + cmd[1] = 0b01010111; // Temparature oversampling x2 010, Pressure oversampling x16 101, Normal mode 11 + i2c.write(address, cmd, 2); + + cmd[0] = 0xf5; // config + cmd[1] = 0b10111100; // Standby 1000ms, Filter x16 + i2c.write(address, cmd, 2); + + cmd[0] = 0x88; // read dig_T regs + i2c.write(address, cmd, 1); + i2c.read(address, cmd, 6); + + dig_T1 = (cmd[1] << 8) | cmd[0]; + dig_T2 = (cmd[3] << 8) | cmd[2]; + dig_T3 = (cmd[5] << 8) | cmd[4]; + + DEBUG_PRINT("dig_T = 0x%x, 0x%x, 0x%x\n\r", dig_T1, dig_T2, dig_T3); + DEBUG_PRINT("dig_T = %d, %d, %d\n\r", dig_T1, dig_T2, dig_T3); + + cmd[0] = 0x8E; // read dig_P regs + i2c.write(address, cmd, 1); + i2c.read(address, cmd, 18); + + dig_P1 = (cmd[ 1] << 8) | cmd[ 0]; + dig_P2 = (cmd[ 3] << 8) | cmd[ 2]; + dig_P3 = (cmd[ 5] << 8) | cmd[ 4]; + dig_P4 = (cmd[ 7] << 8) | cmd[ 6]; + dig_P5 = (cmd[ 9] << 8) | cmd[ 8]; + dig_P6 = (cmd[11] << 8) | cmd[10]; + dig_P7 = (cmd[13] << 8) | cmd[12]; + dig_P8 = (cmd[15] << 8) | cmd[14]; + dig_P9 = (cmd[17] << 8) | cmd[16]; + + DEBUG_PRINT("dig_P = 0x%x, 0x%x, 0x%x, 0x%x, 0x%x, 0x%x, 0x%x, 0x%x, 0x%x\n", dig_P1, dig_P2, dig_P3, dig_P4, dig_P5, dig_P6, dig_P7, dig_P8, dig_P9); + + /* cmd[0] = 0xA1; // read dig_H regs + i2c.write(address, cmd, 1); + i2c.read(address, cmd, 1); + cmd[1] = 0xE1; // read dig_H regs + i2c.write(address, &cmd[1], 1); + i2c.read(address, &cmd[1], 7); + + dig_H1 = cmd[0]; + dig_H2 = (cmd[2] << 8) | cmd[1]; + dig_H3 = cmd[3]; + dig_H4 = (cmd[4] << 4) | (cmd[5] & 0x0f); + dig_H5 = (cmd[6] << 4) | ((cmd[5]>>4) & 0x0f); + dig_H6 = cmd[7]; + + DEBUG_PRINT("dig_H = 0x%x, 0x%x, 0x%x, 0x%x, 0x%x, 0x%x\n", dig_H1, dig_H2, dig_H3, dig_H4, dig_H5, dig_H6); +*/ +} + +float BMP280::getTemperature() +{ + int32_t temp_raw; + float tempf; + char cmd[4]; + + cmd[0] = 0xfa; // temp_msb + i2c.write(address, cmd, 1); + i2c.read(address, &cmd[1], 3); + + temp_raw = (cmd[1] << 12) | (cmd[2] << 4) | (cmd[3] >> 4); + DEBUG_PRINT("\r\ntemp_raw:%d",temp_raw); + + int32_t temp1, temp2,temp; + + temp1 =((((temp_raw >> 3) - (dig_T1 << 1))) * dig_T2) >> 11; + temp2 =(((((temp_raw >> 4) - dig_T1) * ((temp_raw >> 4) - dig_T1)) >> 12) * dig_T3) >> 14; + DEBUG_PRINT(" temp1:%d temp2:%d",temp1, temp2); + t_fine = temp1+temp2; + DEBUG_PRINT(" t_fine:%d",t_fine); + temp = (t_fine * 5 + 128) >> 8; + tempf = (float)temp; + DEBUG_PRINT(" tempf:%f",tempf); + + return (tempf/100.0f); +} + +float BMP280::getPressure() +{ + uint32_t press_raw; + float pressf; + char cmd[4]; + + cmd[0] = 0xf7; // press_msb + i2c.write(address, cmd, 1); + i2c.read(address, &cmd[1], 3); + + press_raw = (cmd[1] << 12) | (cmd[2] << 4) | (cmd[3] >> 4); + + int32_t var1, var2; + uint32_t press; + + var1 = (t_fine >> 1) - 64000; + var2 = (((var1 >> 2) * (var1 >> 2)) >> 11) * dig_P6; + var2 = var2 + ((var1 * dig_P5) << 1); + var2 = (var2 >> 2) + (dig_P4 << 16); + var1 = (((dig_P3 * (((var1 >> 2)*(var1 >> 2)) >> 13)) >> 3) + ((dig_P2 * var1) >> 1)) >> 18; + var1 = ((32768 + var1) * dig_P1) >> 15; + if (var1 == 0) { + return 0; + } + press = (((1048576 - press_raw) - (var2 >> 12))) * 3125; + if(press < 0x80000000) { + press = (press << 1) / var1; + } else { + press = (press / var1) * 2; + } + var1 = ((int32_t)dig_P9 * ((int32_t)(((press >> 3) * (press >> 3)) >> 13))) >> 12; + var2 = (((int32_t)(press >> 2)) * (int32_t)dig_P8) >> 13; + press = (press + ((var1 + var2 + dig_P7) >> 4)); + + pressf = (float)press; + return (pressf/100.0f); +} \ No newline at end of file
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/BMP280.h Sat Jan 05 15:03:12 2019 +0000 @@ -0,0 +1,104 @@ +/** + * BME280 Combined humidity and pressure sensor library + * + * @author Toyomasa Watarai + * @version 1.0 + * @date 06-April-2015 + * + * Library for "BME280 temperature, humidity and pressure sensor module" from Switch Science + * https://www.switch-science.com/catalog/2236/ + * + * For more information about the BME280: + * http://ae-bst.resource.bosch.com/media/products/dokumente/bme280/BST-BME280_DS001-10.pdf + */ + +#ifndef MBED_BMP280_H +#define MBED_BMP280_H + +#include "mbed.h" + +//#define _DEBUG +// default address with SDO High 0x77 +// address with SDO LOW 0x76 +#define DEFAULT_SLAVE_ADDRESS (0x77) + +#ifdef _DEBUG +extern Serial pc; +#define DEBUG_PRINT(...) pc.printf(__VA_ARGS__) +#else +#define DEBUG_PRINT(...) +#endif + + +/** BME280 class + * + * BME280: A library to read environmental data using Bosch BME280 device + * Readds temperature and pressure + * + * BME280 is an environmental sensor + * @endcode + */ + +class BMP280 +{ +public: + + /** Create a BME280 instance + * which is connected to specified I2C pins with specified address + * + * @param sda I2C-bus SDA pin + * @param scl I2C-bus SCL pin + * @param slave_adr (option) I2C-bus address (default: 0x77) + */ + BMP280(PinName sda, PinName sck, char slave_adr = DEFAULT_SLAVE_ADDRESS); + + /** Create a BME280 instance + * which is connected to specified I2C pins with specified address + * + * @param i2c_obj I2C object (instance) + * @param slave_adr (option) I2C-bus address (default: 0x77) + */ + BMP280(I2C &i2c_obj, char slave_adr = DEFAULT_SLAVE_ADDRESS); + + /** Destructor of BME280 + */ + virtual ~BMP280(); + + /** Initializa BME280 sensor + * + * Configure sensor setting and read parameters for calibration + * + */ + void initialize(void); + + /** Read the current temperature value (degree Celsius) from BME280 sensor + * + */ + float getTemperature(void); + + /** Read the current pressure value (hectopascal)from BME280 sensor + * + */ + float getPressure(void); + + /** Read the current humidity value (humidity %) from BME280 sensor + * + */ + // float getHumidity(void); + +private: + + I2C *i2c_p; + I2C &i2c; + char address; + uint16_t dig_T1; + int16_t dig_T2, dig_T3; + uint16_t dig_P1; + int16_t dig_P2, dig_P3, dig_P4, dig_P5, dig_P6, dig_P7, dig_P8, dig_P9; + uint16_t dig_H1, dig_H3; + int16_t dig_H2, dig_H4, dig_H5, dig_H6; + int32_t t_fine; + +}; + +#endif // MBED_BME280_H