/*
* Complete Project Details https://randomnerdtutorials.com
*/
#include <Wire.h>
#include <SPI.h>
#include <Adafruit_Sensor.h>
#include <Adafruit_BME280.h>
// ----------------------------------------
class MyBME280: public Adafruit_BME280 {
public:
MyBME280(int cs, int mosi, int miso, int sck) : Adafruit_BME280(cs, mosi, miso, sck){};
void readAllRegisters(uint8_t *buf) {
buf[0] = uint8_t(0xF7);
// i2c_dev->write_then_read(buf, 1, buf, 8);
spi_dev->write_then_read(buf, 1, buf, 8); // for (int i = 0; i < 8; i++) {
// buf[i] = read8(0xF7+i);
// }
};
void readAllCoefficients(uint8_t *buf) {
uint8_t rdbuf[1] = {0x88};
// i2c_dev->write_then_read(rdbuf, 1, buf, 26);
spi_dev->write_then_read(rdbuf, 1, buf, 26); // for (int i = 0; i < 8; i++) {
rdbuf[0] = uint8_t(0xE1);
spi_dev->write_then_read(rdbuf, 1, buf + 26, 16);
// int i = 0, j=0;
// for (; i < 26; i++) {
// buf[i] = read8(0x88+i);
// }
// for (i = 0; j < 16; j++, i++) {
// buf[i] = read8(0xE1+j);
// }
};
bme280_calib_data *calibData() { return &this->_bme280_calib;}
};
char buf[200];
bme280_calib_data *_calibData;
const char *debugHexStr(uint8_t *p, size_t c) {
static char hb[] = "0123456789ABCDEF";
char *pb = (char *)buf;
//c = constrain(c, 1, 16);
for (; c--;) {
*pb++ = hb[(*p & 0xF0) >> 4];
*pb++ = hb[*p & 0x0F ];
*pb++ = ',';
p++;
}
*pb = 0;
return buf;
}
// ------------------------------------------------------
#define BME_SCK 52
#define BME_MISO 50
#define BME_MOSI 51
#define BME_CS 53
#define SEALEVELPRESSURE_HPA (1013.25)
// Adafruit_BME280 bme; // I2C
// Adafruit_BME280 bme(BME_CS); // hardware SPI
MyBME280 bme(BME_CS, BME_MOSI, BME_MISO, BME_SCK); // software SPI
unsigned long delayTime;
void setup() {
Serial.begin(115200);
Serial.println(F("BME280 test"));
pinMode(2, OUTPUT);
digitalWrite(2, LOW);
bool status;
#ifdef BUSIO_HAS_HW_SPI
Serial.println("using SPI with hw: ");
#endif
// default settings
// (you can also pass in a Wire library object like &Wire2)
status = bme.begin();
if (!status) {
Serial.println("Could not find a valid BME280 sensor, check wiring!");
while (1);
}
Serial.println("-- Coefficient registers --");
static uint8_t cbuf[128];
bme.readAllCoefficients(cbuf);
Serial.println( debugHexStr(cbuf, 42));
bme280_calib_data * _calibData = bme.calibData();
Serial.print("dig_T1: "); Serial.println(_calibData->dig_T1);
Serial.print("dig_T2: "); Serial.println(_calibData->dig_T2);
Serial.print("dig_T3: "); Serial.println(_calibData->dig_T3);
Serial.println("-- Default Test --");
delayTime = 1000;
Serial.println();
}
void loop() {
printValues();
delay(delayTime);
}
uint8_t registers[8];
void printValues() {
static uint8_t buf[128];
Serial.print(millis());
Serial.print(" T = ");
Serial.print(bme.readTemperature());
Serial.print(" *C");
// ------
Serial.print(", P = ");
Serial.print(bme.readPressure() / 100.0F);
Serial.print(" hPa");
// ------
Serial.print(", A = ");
Serial.print(bme.readAltitude(SEALEVELPRESSURE_HPA));
Serial.print(" m");
Serial.print("H = ");
Serial.print(bme.readHumidity());
Serial.print(" %");
bme.readAllRegisters(registers);
Serial.print( ", R: ");
Serial.print(debugHexStr(registers, 8));
Serial.println();
}
int32_t t_fine;
int32_t t_fine_adjust = 0;
uint32_t _read24(byte off) {
uint8_t buffer[3];
buffer[0] = registers[off++];
buffer[1] = registers[off++];
buffer[2] = registers[off++];
return uint32_t(buffer[0]) << 16 | uint32_t(buffer[1]) << 8 |
uint32_t(buffer[2]);
}
uint16_t _read16(byte off) {
uint8_t buffer[2];
buffer[0] = registers[off++];
buffer[1] = registers[off++];
return uint16_t(buffer[0]) << 8 | uint16_t(buffer[1]);
}
float _readTemperature(void) {
int32_t var1, var2;
int32_t adc_T = _read24(3);
Serial.print(" t1: "); Serial.print(_calibData->dig_T1);
Serial.print(" t2: "); Serial.print(_calibData->dig_T2);
Serial.print(" t3: "); Serial.print(_calibData->dig_T3);
Serial.println();
Serial.print(" rt: "); Serial.print(adc_T, HEX); Serial.print(" " );
if (adc_T == 0x800000) // value in case temp measurement was disabled
return NAN;
adc_T >>= 4;
Serial.print(" srt: "); Serial.print(adc_T, HEX); Serial.print(" " ); Serial.print(adc_T);
var1 = (int32_t)((adc_T / 8) - ((int32_t)_calibData->dig_T1 * 2));
Serial.println();
Serial.print(" v1: "); Serial.print(var1);
var1 = (var1 * ((int32_t)_calibData->dig_T2)) / 2048;
Serial.println();
Serial.print(" v1`: "); Serial.print(var1);
var2 = (int32_t)((adc_T / 16) - ((int32_t)_calibData->dig_T1));
Serial.println();
Serial.print(" v2: "); Serial.print(var2);
var2 = (((var2 * var2) / 4096) * ((int32_t)_calibData->dig_T3)) / 16384;
Serial.println();
Serial.print(" v2`: "); Serial.print(var2);
t_fine = var1 + var2 + t_fine_adjust;
Serial.println();
Serial.print(" tf: "); Serial.print(t_fine);
int32_t T = (t_fine * 5 + 128) / 256;
Serial.println();
Serial.print(" T: "); Serial.print(((float)T)/100.0);
Serial.println();
return (float)T / 100;
}
/*!
* @brief Returns the pressure from the sensor
* @returns the pressure value (in Pascal) read from the device
*/
float _readPressure(void) {
int64_t var1, var2, var3, var4;
_readTemperature(); // must be done first to get t_fine
int32_t adc_P = _read24(0);
if (adc_P == 0x800000) // value in case pressure measurement was disabled
return NAN;
adc_P >>= 4;
var1 = ((int64_t)t_fine) - 128000;
var2 = var1 * var1 * (int64_t)_calibData->dig_P6;
var2 = var2 + ((var1 * (int64_t)_calibData->dig_P5) * 131072);
var2 = var2 + (((int64_t)_calibData->dig_P4) * 34359738368);
var1 = ((var1 * var1 * (int64_t)_calibData->dig_P3) / 256) +
((var1 * ((int64_t)_calibData->dig_P2) * 4096));
var3 = ((int64_t)1) * 140737488355328;
var1 = (var3 + var1) * ((int64_t)_calibData->dig_P1) / 8589934592;
if (var1 == 0) {
return 0; // avoid exception caused by division by zero
}
var4 = 1048576 - adc_P;
var4 = (((var4 * 2147483648) - var2) * 3125) / var1;
var1 = (((int64_t)_calibData->dig_P9) * (var4 / 8192) * (var4 / 8192)) /
33554432;
var2 = (((int64_t)_calibData->dig_P8) * var4) / 524288;
var4 = ((var4 + var1 + var2) / 256) + (((int64_t)_calibData->dig_P7) * 16);
float P = var4 / 256.0;
return P;
}
/*!
* @brief Returns the humidity from the sensor
* @returns the humidity value read from the device
*/
float _readHumidity(void) {
int32_t var1, var2, var3, var4, var5;
_readTemperature(); // must be done first to get t_fine
int32_t adc_H = _read16(6);
if (adc_H == 0x8000) // value in case humidity measurement was disabled
return NAN;
var1 = t_fine - ((int32_t)76800);
var2 = (int32_t)(adc_H * 16384);
var3 = (int32_t)(((int32_t)_calibData->dig_H4) * 1048576);
var4 = ((int32_t)_calibData->dig_H5) * var1;
var5 = (((var2 - var3) - var4) + (int32_t)16384) / 32768;
var2 = (var1 * ((int32_t)_calibData->dig_H6)) / 1024;
var3 = (var1 * ((int32_t)_calibData->dig_H3)) / 2048;
var4 = ((var2 * (var3 + (int32_t)32768)) / 1024) + (int32_t)2097152;
var2 = ((var4 * ((int32_t)_calibData->dig_H2)) + 8192) / 16384;
var3 = var5 * var2;
var4 = ((var3 / 32768) * (var3 / 32768)) / 128;
var5 = var3 - ((var4 * ((int32_t)_calibData->dig_H1)) / 16);
var5 = (var5 < 0 ? 0 : var5);
var5 = (var5 > 419430400 ? 419430400 : var5);
uint32_t H = (uint32_t)(var5 / 4096);
return (float)H / 1024.0;
}