BME280.h

00001 #ifndef BME_H
00002 #define BME_H
00003 
00004 #include "mbed.h"
00005 
00006 #define _debug   1      // '1' to enable prinf BME's registers
00007 
00008 /*
00009 Bosch Sensortec BMP280 BME280 i2c example code
00010 using 64bit numeric calculations as recomended by Bosch.
00011 Some sensors supplied from Chinese suppliers may have 'suspect'
00012 quality sensor with different i2c address.
00013 My sensors were address 0xEC and all the ones I have
00014 differ quite a bit in tolerance :( so be aware if accuracy is paramount.
00015 */
00016 
00017 /*
00018 #include "mbed.h"
00019 #include "BME280.h"
00020 
00021 BME sensor(D0,D1, 0xEC); // sda, clk, 8bit address (NUCLEO-L432)
00022 DigitalOut led(LED1);
00023 
00024 float temp, humidity, pressure, altitude;
00025 
00026 int main()
00027 {
00028 
00029     int BMPE_id = sensor.init();    // initialise and get sensor id
00030 
00031     if(!BMPE_id) {
00032         printf("No sensor detected!!\n");
00033         while(1){
00034             led=!led;
00035             ThisThread::sleep_for(200ms);
00036         }
00037     }
00038      
00039     if(_debug){ // set _debug to '1' to see BME's registers
00040         ThisThread::sleep_for(2s);
00041         }
00042     
00043     while(1) {
00044         led=1;
00045         printf("\033[0m\033[2J\033[H------- BME280-BMP280 Sensor example -------\r\n\n");
00046         if(BMPE_id==0x60) {
00047             printf("BME280 detected id: 0x%x\n\n",BMPE_id);
00048         } else if(BMPE_id==0x58) {
00049             printf("BMP280 detected id: 0x%x\n\n",BMPE_id);
00050         }
00051 
00052         temp = sensor.getTemperature();
00053             
00054         printf("Temperature: %3.2f %cc \n",temp,0xb0);
00055 
00056         if(sensor.chip_id==0x60) {        // only BME has Humidity
00057             humidity    = sensor.getHumidity();
00058             printf("Humidity:    %2.2f %cRh \n", humidity,0x25);
00059         }
00060         pressure    = sensor.getPressure();
00061         printf("Pressure:    %4.2f mbar's \n\n",pressure);
00062 
00063         altitude = 44330.0f*( 1.0f - pow((pressure/1013.25f), (1.0f/5.255f)))+18;     // Calculate altitude in meters
00064         printf("Altitude: %3.1f meters   %4.1f feet \r\n(Referenced to 1,013.25 millibars @ sea level) \r\n\n", altitude,altitude*3.2810f);
00065         led=0;
00066         ThisThread::sleep_for(1s);
00067     }
00068 }
00069 */
00070 
00071 class BME
00072 {
00073 public:
00074 
00075     BME(PinName sda, PinName scl, char slave_adr);
00076 
00077     int         init(void);
00078     int         chipID(void);
00079     float       getTemperature(void);
00080     float       getPressure(void);
00081     float       getHumidity(void);
00082   
00083     uint16_t    chip_id;
00084 
00085 private:
00086 
00087     I2C         bme;
00088     void        initialize(void);
00089     char        address;
00090     uint16_t    dig_T1;
00091     int16_t     dig_T2, dig_T3;
00092     uint16_t    dig_P1;
00093     int16_t     dig_P2, dig_P3, dig_P4, dig_P5, dig_P6, dig_P7, dig_P8, dig_P9;
00094     uint16_t    dig_H1, dig_H3;
00095     int16_t     dig_H2, dig_H4, dig_H5, dig_H6;
00096     int32_t     t_fine;
00097     bool        dbg_on;
00098 };
00099 #endif // BME_H