v3_firmware/firmware/BME280.cpp

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#include <Arduino.h>
#include <stdint.h>
#include <Wire.h>
#include "BME280.h"
BME280::BME280() {}
void BME280::getCalData() {
dig_T1 = read16_LE(0x88);
dig_T2 = readS16_LE(0x8A);
dig_T3 = readS16_LE(0x8C);
dig_P1 = read16_LE(0x8E);
dig_P2 = readS16_LE(0x90);
dig_P3 = readS16_LE(0x92);
dig_P4 = readS16_LE(0x94);
dig_P5 = readS16_LE(0x96);
dig_P6 = readS16_LE(0x98);
dig_P7 = readS16_LE(0x9A);
dig_P8 = readS16_LE(0x9C);
dig_P9 = readS16_LE(0x9E);
dig_H1 = read8(0xA1);
dig_H2 = readS16_LE(0xE1);
dig_H3 = read8(0xE3);
dig_H4 = (read8(0xE4) << 4) | (read8(0xE5) & 0xF);
dig_H5 = (read8(0xE6) << 4) | (read8(0xE5) >> 4);
dig_H6 = (int8_t)read8(0xE7);
}
int32_t BME280::compensate_t(int32_t adc_T)
{
int32_t var1, var2, T;
var1 = ((((adc_T>>3) - ((int32_t)dig_T1<<1))) * ((int32_t)dig_T2)) >> 11;
var2 = (((((adc_T>>4) - ((int32_t)dig_T1)) * ((adc_T>>4) - ((int32_t)dig_T1))) >> 12) * ((int32_t)dig_T3)) >> 14;
t_fine = var1 + var2;
T = (t_fine * 5 + 128) >> 8;
return T;
}
int32_t BME280::compensate_p(int32_t adc_P)
{
int32_t var1, var2;
uint32_t p;
var1 = (((int32_t)t_fine)>>1) -(int32_t)64000;
var2 = (((var1>>2) * (var1>>2)) >> 11 ) * ((int32_t)dig_P6);
var2 = var2 + ((var1*((int32_t)dig_P5))<<1);var2 = (var2>>2)+(((int32_t)dig_P4)<<16);
var1 = (((dig_P3 * (((var1>>2) * (var1>>2)) >> 13 )) >> 3) + ((((int32_t)dig_P2) * var1)>>1))>>18;
var1 =((((32768+var1))*((int32_t)dig_P1))>>15);
if (var1 == 0) {
return 0;
}
p = (((uint32_t)(((int32_t)1048576)-adc_P)-(var2>>12)))*3125;
if (p < 0x80000000) {
p = (p << 1) / ((uint32_t)var1);
} else {
p = (p / (uint32_t)var1) * 2;
}
var1 = (((int32_t)dig_P9) * ((int32_t)(((p>>3) * (p>>3))>>13)))>>12;
var2 = (((int32_t)(p>>2)) * ((int32_t)dig_P8))>>13;
p = (uint32_t)((int32_t)p + ((var1 + var2 + dig_P7) >> 4));
return p;
}
int32_t BME280::compensate_h(int32_t adc_H)
{
int32_t v_x1_u32r;
v_x1_u32r=(t_fine-((int32_t)76800));
v_x1_u32r=(((((adc_H<<14)-(((int32_t)dig_H4)<<20)-(((int32_t)dig_H5)*v_x1_u32r))+
((int32_t)16384))>>15)*(((((((v_x1_u32r*((int32_t)dig_H6))>>10)*
(((v_x1_u32r*((int32_t)dig_H3))>>11)+((int32_t)32768)))>>10)+
((int32_t)2097152))*((int32_t)dig_H2)+8192)>>14));
v_x1_u32r=(v_x1_u32r-(((((v_x1_u32r>>15)*(v_x1_u32r>>15))>>7)*((int32_t)dig_H1))>>4));
v_x1_u32r=(v_x1_u32r < 0 ? 0 : v_x1_u32r);
v_x1_u32r=(v_x1_u32r > 419430400 ? 419430400 : v_x1_u32r);
return (uint32_t)((v_x1_u32r>>12)/10);
}
void BME280::getData(int32_t *t, int32_t *p, int32_t *h) {
int32_t UP, UT, UH;
int32_t rawP, rawT;
// Trigger Measurement
// Set Sensor Config
write8(0xF2, 0b00000001); // 1x Oversampling for Humidity
write8(0xF4, 0b00100101); // 1x Oversampling for Temperature, Pressure, Forced Mode
delay(10);
// Read Pressure
rawP = read16(0xF7);
rawP <<= 8;
rawP |= read8(0xF9);
UP = rawP >> 4;
// Read Temperature
rawT = read16(0xFA);
rawT <<= 8;
rawT |= read8(0xFC);
UT = rawT >> 4;
// Read Humidity
UH = read16(0xFD);
// Compensate Values and Return
*t = compensate_t(UT);
*p = compensate_p(UP);
*h = compensate_h(UH);
}
uint8_t BME280::read8(uint8_t addr) {
Wire.beginTransmission(BME280_I2CADDR);
Wire.write(addr);
Wire.endTransmission();
Wire.requestFrom(BME280_I2CADDR, 1);
uint8_t ret = Wire.read();
return ret;
}
uint16_t BME280::read16(uint8_t addr) {
Wire.beginTransmission(BME280_I2CADDR);
Wire.write(addr);
Wire.endTransmission();
Wire.requestFrom(BME280_I2CADDR, 2);
uint16_t ret = (Wire.read() << 8) | Wire.read();
return ret;
}
uint16_t BME280::read16_LE(uint8_t addr) {
uint16_t temp = read16(addr);
return (temp >> 8) | (temp << 8);
}
int16_t BME280::readS16(uint8_t addr) {
return (int16_t)read16(addr);
}
int16_t BME280::readS16_LE(uint8_t addr) {
return (int16_t)read16_LE(addr);
}
void BME280::write8(uint8_t addr, uint8_t data) {
Wire.beginTransmission(BME280_I2CADDR);
Wire.write(addr);
Wire.write(data);
Wire.endTransmission();
}