esp32-node/src/BME280.cpp

#include "BME280.h"

#include <Wire.h>
#include <SPI.h>
#include <Adafruit_Sensor.h>
#include <Adafruit_BME280.h>

BME280::BME280() {
  valid = false;
}

bool BME280::begin(void) {
  SPI.begin(BME_SCK, BME_MISO, BME_MOSI, BME_CS);
  pinMode(18, OUTPUT);
  digitalWrite(18, HIGH); // disable LoRa_CS
  pinMode(BME_CS, OUTPUT);
  digitalWrite(BME_CS, LOW);  // enable bme280 CS
  delay(100);
//  bme = new Adafruit_BME280(BME_CS, BME_MOSI, BME_MISO, BME_SCK); // software SPI
  bme = new Adafruit_BME280(BME_CS); // hardware SPI

  bme->setSampling(Adafruit_BME280::sensor_mode::MODE_NORMAL,
                   Adafruit_BME280::sensor_sampling::SAMPLING_X8,
                   Adafruit_BME280::sensor_sampling::SAMPLING_X8,
                   Adafruit_BME280::sensor_sampling::SAMPLING_X8,
                   Adafruit_BME280::sensor_filter::FILTER_OFF,
                   Adafruit_BME280::standby_duration::STANDBY_MS_250);

  valid = bme->begin();
  if (!valid) bme->init();

  if (!valid) return false;
  return true;
}

void BME280::sleep() {
  bme->setSampling(Adafruit_BME280::sensor_mode::MODE_SLEEP,
                   Adafruit_BME280::sensor_sampling::SAMPLING_X16,
                   Adafruit_BME280::sensor_sampling::SAMPLING_X16,
                   Adafruit_BME280::sensor_sampling::SAMPLING_X16,
                   Adafruit_BME280::sensor_filter::FILTER_OFF,
                   Adafruit_BME280::standby_duration::STANDBY_MS_1000);
}

bool BME280::reinit() {
  pinMode(18, OUTPUT);
  digitalWrite(18, HIGH); // disable LoRa_CS
  pinMode(BME_CS, OUTPUT);
//  digitalWrite(BME_CS, LOW);  // enable bme280 CS

  valid = false;
  for (int retries=0; !valid && retries<5; retries++) {
    /* reset chip */
    Serial.println("resetting BME280");
    SPI.beginTransaction(SPISettings(500000, MSBFIRST, SPI_MODE0));
    digitalWrite(BME_CS, LOW);
    constexpr byte BME280_REGISTER_SOFTRESET = 0xE0;
    SPI.transfer(BME280_REGISTER_SOFTRESET & ~0x80);
    SPI.transfer(0xB6);
    digitalWrite(BME_CS, HIGH);
    SPI.endTransaction(); // release the SPI bus
    delay(300); // wait for chip to wake up

    valid = bme->init();
    retries++;

    checkValid();
  }
  if (!valid) {
    Serial.println("Could not find a valid BME280 sensor, check wiring!");
    return false;
  }
}

void BME280::printValues() {
    Serial.print("Temperature = ");
    Serial.print(bme->readTemperature());
    Serial.println(" *C");

    Serial.print("Pressure = ");

    Serial.print(bme->readPressure() / 100.0F);
    Serial.println(" hPa");

    Serial.print("Approx. Altitude = ");
    Serial.print(bme->readAltitude(SEALEVELPRESSURE_HPA));
    Serial.println(" m");

    Serial.print("Humidity = ");
    Serial.print(bme->readHumidity());
    Serial.println(" %");

    Serial.println();
}

float BME280::readTemperature(void) {
  float temp = bme->readTemperature();
  if (temp < -40 || temp > 85) valid = false;
  else valid = true;
  return temp;
}
float BME280::readPressure(void) {
  float p = bme->readPressure() / 100.0F;
  if (p < 300 || p > 1100) valid = false;
  else valid = true;
  return p;
}
float BME280::readHumidity(void) {
  float h = bme->readHumidity();
  if (h < 0 || h > 100) valid = false;
  else valid = true;
  return h;
}

bool BME280::checkValid(void) {
   readPressure();
   return valid;
}