BMP280から気圧データを取得します。updateで更新動作、getpressで値を読み出します
Diff: BMP280.cpp
- Revision:
- 0:54d7f18450e6
- Child:
- 1:a65c7f637b1e
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/BMP280.cpp Sun Dec 04 14:38:21 2016 +0000 @@ -0,0 +1,131 @@ +#include "BMP280.h" + + +BMP280::BMP280(PinName mosi,PinName miso,PinName sck,PinName _cs):bmp(mosi,miso,sck),cs(_cs) +{ + cs=1; + bmp.frequency(1000000); + bmp.format(8,3); + + wait(0.1); + press=0; + + writebyte(0xe0,0xb6);//reset + wait_ms(100); + + char buf[2]; + while((readbyte(0xf3)&0b00000001)); + + readnbyte(0x88,buf,2); + dig_T1=((unsigned short)(buf[1]<<8)|buf[0]); + readnbyte(0x8a,buf,2); + dig_T2=((short)(buf[1]<<8)|buf[0]); + readnbyte(0x8c,buf,2); + dig_T3=((short)(buf[1]<<8)|buf[0]); + readnbyte(0x8e,buf,2); + dig_P1=((unsigned short)(buf[1]<<8)|buf[0]); + readnbyte(0x90,buf,2); + dig_P2=((short)(buf[1]<<8)|buf[0]); + readnbyte(0x92,buf,2); + dig_P3=((short)(buf[1]<<8)|buf[0]); + readnbyte(0x94,buf,2); + dig_P4=((short)(buf[1]<<8)|buf[0]); + readnbyte(0x96,buf,2); + dig_P5=((short)(buf[1]<<8)|buf[0]); + readnbyte(0x98,buf,2); + dig_P6=((short)(buf[1]<<8)|buf[0]); + readnbyte(0x9a,buf,2); + dig_P7=((short)(buf[1]<<8)|buf[0]); + readnbyte(0x9c,buf,2); + dig_P8=((short)(buf[1]<<8)|buf[0]); + readnbyte(0x9e,buf,2); + dig_P9=((short)(buf[1]<<8)|buf[0]); + +} + +void BMP280::init(char t_osr,char p_osr,char t_sb,char IIR){ + char data=((t_osr<<5)|(p_osr<<2))|0b11; + writebyte(0xf4,data);//config + + data=0; + data=(t_sb<<5)|(IIR<<2); + writebyte(0xf5,data); +} + +char BMP280::readbyte(char adr){ + cs=0; + bmp.write(adr|0b10000000); + char val=bmp.write(0xff); + cs=1; + return val; + +} +void BMP280::writebyte(char adr,char data){ + cs=0; + bmp.write(adr&0b1111111); + bmp.write(data); + cs=1; +} +void BMP280::readnbyte(char adr,char *data,char num){ + cs=0; + bmp.write(adr|0b10000000); + for(int i=0;i<num;i++)data[i]=bmp.write(0xff); + cs=1; +} + +int BMP280::bmp280_compensate_T_int32(int adc_T){ + int var1,var2,T; + var1=((((adc_T>>3)-((int)dig_T1<<1)))*((int)dig_T2))>>11; + var2=(((((adc_T>>4)-((int)dig_T1))*((adc_T>>4)-((int)dig_T1)))>>12)*((int)dig_T3))>>14; + t_fine=var1+var2; + T=(t_fine*5+128)>>8; + return T; + +} +unsigned int BMP280::bmp280_compensate_P_int64(int adc_P){ + int32_t var1, var2; + unsigned int press=0; + + 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 - adc_P) - (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)); + + return press; +} +bool BMP280::update(){ + if(((readbyte(0xf3)&0b00001000)>>3)==0){//データが見れるか + + char data[6]; + int adc_T,adc_P; + readnbyte(0xf7,data,6); + adc_T=(int)((data[4]<<4)|(data[3]<<12))|(data[5]>>4); + + adc_P=(int)((data[2]>>4)|(data[1]<<4))|(data[0]<<12); + + bmp280_compensate_T_int32(adc_T); + press=bmp280_compensate_P_int64(adc_P); + + return true; + } + +return false; +} + +float BMP280::getpress(){ + return (float)press; +} \ No newline at end of file