Changes between Version 7 and Version 8 of BME280

Timestamp:

Apr 1, 2015 10:35:09 AM (9 years ago)

Author:

soumura

Comment:

--

BME280

@@ -85 +85 @@
 [[BR]]
 
-= サンプルスケッチ =
+= 使い方 =
 レジスタの設定値が決定したので値をレジスタに書込み測定を開始します。[[BR]]
 気圧の情報はレジスタのアドレス　0xF7 0xF8 0xF9に格納されます。[[BR]]
@@ -98 +98 @@
 [[Image(BME280_5.JPG)]]
 
-
-
+[[Image(s-BME280_12.jpg)]]
+
+=== サンプルスケッチ ===
+{{{
+#include <Wire.h>
+
+#define BME280_ADDRESS 0x76
+unsigned long int hum_raw,temp_raw,pres_raw;
+signed long int t_fine;
+
+uint16_t dig_T1;
+ int16_t dig_T2;
+ int16_t dig_T3;
+uint16_t dig_P1;
+ int16_t dig_P2;
+ int16_t dig_P3;
+ int16_t dig_P4;
+ int16_t dig_P5;
+ int16_t dig_P6;
+ int16_t dig_P7;
+ int16_t dig_P8;
+ int16_t dig_P9;
+ int8_t  dig_H1;
+ int16_t dig_H2;
+ int8_t  dig_H3;
+ int16_t dig_H4;
+ int16_t dig_H5;
+ int8_t  dig_H6;
+
+void setup()
+{
+    uint8_t osrs_t = 1;             //Temperature oversampling x 1
+    uint8_t osrs_p = 1;             //Pressure oversampling x 1
+    uint8_t osrs_h = 1;             //Humidity oversampling x 1
+    uint8_t mode = 3;               //Normal mode
+    uint8_t t_sb = 5;               //Tstandby 1000ms
+    uint8_t filter = 0;             //Filter off 
+    uint8_t spi3w_en = 0;           //3-wire SPI Disable
+    
+    uint8_t ctrl_meas_reg = (osrs_t << 5) | (osrs_p << 2) | mode;
+    uint8_t config_reg    = (t_sb << 5) | (filter << 2) | spi3w_en;
+    uint8_t ctrl_hum_reg  = osrs_h;
+    
+    Serial.begin(9600);
+    Wire.begin();
+    
+    writeReg(0xF2,ctrl_hum_reg);
+    writeReg(0xF4,ctrl_meas_reg);
+    writeReg(0xF5,config_reg);
+    readTrim();                    //
+}
+
+
+void loop()
+{
+    double temp_act = 0.0, press_act = 0.0,hum_act=0.0;
+    signed long int temp_cal;
+    unsigned long int press_cal,hum_cal;
+    
+    readData();
+    
+    temp_cal = calibration_T(temp_raw);
+    press_cal = calibration_P(pres_raw);
+    hum_cal = calibration_H(hum_raw);
+    temp_act = (double)temp_cal / 100.0;
+    press_act = (double)press_cal / 100.0;
+    hum_act = (double)hum_cal / 1024.0;
+    Serial.print("TEMP : ");
+    Serial.print(temp_act);
+    Serial.print(" DegC  PRESS : ");
+    Serial.print(press_act);
+    Serial.print(" hPa  HUM : ");
+    Serial.print(hum_act);
+    Serial.println(" %");    
+    
+    delay(1000);
+}
+void readTrim()
+{
+    uint8_t data[33],i=0;
+    Wire.beginTransmission(BME280_ADDRESS);
+    Wire.write(0x88);
+    Wire.endTransmission();
+    Wire.requestFrom(BME280_ADDRESS,25);
+    while(Wire.available()){
+        data[i] = Wire.read();
+        i++;
+    }
+    Wire.beginTransmission(BME280_ADDRESS);
+    Wire.write(0xE1);
+    Wire.endTransmission();
+    Wire.requestFrom(BME280_ADDRESS,8);
+    while(Wire.available()){
+        data[i] = Wire.read();
+        i++;    
+    }
+    dig_T1 = (data[1] << 8) | data[0];
+    dig_T2 = (data[3] << 8) | data[2];
+    dig_T3 = (data[5] << 8) | data[4];
+    dig_P1 = (data[7] << 8) | data[6];
+    dig_P2 = (data[9] << 8) | data[8];
+    dig_P3 = (data[11]<< 8) | data[10];
+    dig_P4 = (data[13]<< 8) | data[12];
+    dig_P5 = (data[15]<< 8) | data[14];
+    dig_P6 = (data[17]<< 8) | data[16];
+    dig_P7 = (data[19]<< 8) | data[18];
+    dig_P8 = (data[21]<< 8) | data[20];
+    dig_P9 = (data[23]<< 8) | data[22];
+    dig_H1 = data[24];
+    dig_H2 = (data[26]<< 8) | data[25];
+    dig_H3 = data[27];
+    dig_H4 = (data[28]<< 4) | (0x0F & data[29]);
+    dig_H5 = (data[31] << 4) | ((data[30] >> 4) & 0x0F);
+    dig_H6 = data[32];   
+}
+void writeReg(uint8_t reg_address, uint8_t data)
+{
+    Wire.beginTransmission(BME280_ADDRESS);
+    Wire.write(reg_address);
+    Wire.write(data);
+    Wire.endTransmission();    
+}
+
+
+void readData()
+{
+    int i = 0;
+    uint32_t data[8];
+    Wire.beginTransmission(BME280_ADDRESS);
+    Wire.write(0xF7);
+    Wire.endTransmission();
+    Wire.requestFrom(BME280_ADDRESS,8);
+    while(Wire.available()){
+        data[i] = Wire.read();
+        i++;
+    }
+    pres_raw = (data[0] << 12) | (data[1] << 4) | (data[2] >> 4);
+    temp_raw = (data[3] << 12) | (data[4] << 4) | (data[5] >> 4);
+    hum_raw  = (data[6] << 8) | data[7];
+}
+
+
+signed long int calibration_T(signed long int adc_T)
+{
+    
+    signed long int var1, var2, T;
+    var1 = ((((adc_T >> 3) - ((signed long int)dig_T1<<1))) * ((signed long int)dig_T2)) >> 11;
+    var2 = (((((adc_T >> 4) - ((signed long int)dig_T1)) * ((adc_T>>4) - ((signed long int)dig_T1))) >> 12) * ((signed long int)dig_T3)) >> 14;
+    
+    t_fine = var1 + var2;
+    T = (t_fine * 5 + 128) >> 8;
+    return T; 
+}
+
+unsigned long int calibration_P(signed long int adc_P)
+{
+    signed long int var1, var2;
+    unsigned long int P;
+    var1 = (((signed long int)t_fine)>>1) - (signed long int)64000;
+    var2 = (((var1>>2) * (var1>>2)) >> 11) * ((signed long int)dig_P6);
+    var2 = var2 + ((var1*((signed long int)dig_P5))<<1);
+    var2 = (var2>>2)+(((signed long int)dig_P4)<<16);
+    var1 = (((dig_P3 * (((var1>>2)*(var1>>2)) >> 13)) >>3) + ((((signed long int)dig_P2) * var1)>>1))>>18;
+    var1 = ((((32768+var1))*((signed long int)dig_P1))>>15);
+    if (var1 == 0)
+    {
+        return 0;
+    }    
+    P = (((unsigned long int)(((signed long int)1048576)-adc_P)-(var2>>12)))*3125;
+    if(P<0x80000000)
+    {
+       P = (P << 1) / ((unsigned long int) var1);   
+    }
+    else
+    {
+        P = (P / (unsigned long int)var1) * 2;    
+    }
+    var1 = (((signed long int)dig_P9) * ((signed long int)(((P>>3) * (P>>3))>>13)))>>12;
+    var2 = (((signed long int)(P>>2)) * ((signed long int)dig_P8))>>13;
+    P = (unsigned long int)((signed long int)P + ((var1 + var2 + dig_P7) >> 4));
+    return P;
+}
+
+unsigned long int calibration_H(signed long int adc_H)
+{
+    signed long int v_x1;
+    
+    v_x1 = (t_fine - ((signed long int)76800));
+    v_x1 = (((((adc_H << 14) -(((signed long int)dig_H4) << 20) - (((signed long int)dig_H5) * v_x1)) + 
+              ((signed long int)16384)) >> 15) * (((((((v_x1 * ((signed long int)dig_H6)) >> 10) * 
+              (((v_x1 * ((signed long int)dig_H3)) >> 11) + ((signed long int) 32768))) >> 10) + (( signed long int)2097152)) * 
+              ((signed long int) dig_H2) + 8192) >> 14));
+   v_x1 = (v_x1 - (((((v_x1 >> 15) * (v_x1 >> 15)) >> 7) * ((signed long int)dig_H1)) >> 4));
+   v_x1 = (v_x1 < 0 ? 0 : v_x1);
+   v_x1 = (v_x1 > 419430400 ? 419430400 : v_x1);
+   return (unsigned long int)(v_x1 >> 12);   
+}
+
+}}}
+
+