bme280.cpp

bme280.cpp

#include <SPI.h>

struct strCALIBRATION_DATA {
    uint16_t T1;
   int16_t T2;
   int16_t T3;

  uint16_t P1;
   int16_t P2;
   int16_t P3;
   int16_t P4;
   int16_t P5;
   int16_t P6;
   int16_t P7;
   int16_t P8;
   int16_t P9;

  uint8_t  H1;
   int16_t H2;
  uint8_t  H3;
   int16_t H4;
   int16_t H5;
   int8_t  H6;
} calibration_data;

void writeRegister(uint8_t reg_address, uint8_t data) {
  SPI.transfer(reg_address & B01111111);
  SPI.transfer(data);
}

uint16_t read16bit(uint8_t reg) {
  SPI.transfer(reg | B10000000);
  uint16_t d1 = SPI.transfer(0x00);
  uint16_t d2 = SPI.transfer(0x00);

  return (d2 << 8) | d1;
}

uint8_t read8bit(uint8_t reg) {
  SPI.transfer(reg | B10000000); // read, bit 7 high
  uint8_t data = SPI.transfer(0x00);
  return data;
}

void setup() {
  // put your setup code here, to run once:
  SPI.begin(SCK, MISO, MOSI, SS);
  SPI.setFrequency(10000000);
  SPI.setDataMode(SPI_MODE3);

  uint8_t osrs_t = 4; //OverSampling Temperature x4
  uint8_t osrs_p = 4; //OverSampling Pressure x4
  uint8_t osrs_h = 4; //OverSampling Humidity x4

  writeRegister(0xE0, 0xB6); //reset
  delay(2000);
  writeRegister(0xF2, 4/* OverSampling Humidity*/);
  writeRegister(0xF4, (4/*OverSampling Temperature*/ << 5) | (4/*OverSampling Pressure*/ << 2) | 3 /* Normal mode*/);
  writeRegister(0xF5, (5/*Stand-by 1000ms*/ << 5) | (0/* filter off*/ << 2) | 0 /* 4-wire SPI*/);

  calibration_data.T1 = read16bit(0x88);
  calibration_data.T2 = (int16_t)read16bit(0x8A);
  calibration_data.T3 = (int16_t)read16bit(0x8C);

  calibration_data.P1 = read16bit(0x8E);
  calibration_data.P2 = (int16_t)read16bit(0x90);
  calibration_data.P3 = (int16_t)read16bit(0x92);
  calibration_data.P4 = (int16_t)read16bit(0x94);
  calibration_data.P5 = (int16_t)read16bit(0x96);
  calibration_data.P6 = (int16_t)read16bit(0x98);
  calibration_data.P7 = (int16_t)read16bit(0x9A);
  calibration_data.P8 = (int16_t)read16bit(0x9C);
  calibration_data.P9 = (int16_t)read16bit(0x9E);

  calibration_data.H1 = read8bit(0xA1);
  calibration_data.H2 = (int16_t)read16bit(0xE1);
  calibration_data.H3 = read8bit(0xE3);
  calibration_data.H4 = (int16_t)((read8bit(0xE4) << 4) | (read8bit(0xE5) & 0x0F));
  calibration_data.H5 = (int16_t)((read8bit(0xE6) << 4) | (read8bit(0xE5) >> 4));
  calibration_data.H6 = (int8_t)read8bit(0xE7);
  
  Serial.begin(115200);
  Serial.printf("SCK=%d, MISO=%d, MOSI=%d, SS=%d\n", SCK,MISO,MOSI,SS);
}

void loop() {
  // put your main code here, to run repeatedly:
  Serial.println("Hello, World!");
  delay(1000);
}