ESP32 Dengan BMP280

Berikut ini antar muka minimalis antara ESP32 dengan sensor lingkungan BMP280

Pin yang dipakai:

• VCC di ESP32 dihubungkan ke VCC di BMP280
• GND di ESP32 dihubungkan ke GND di BMP280
• SCL di ESP32 dihubungkan ke SCL di BMP280
• SDA di ESP32 dihubungkan ke SDA di BMP280

Software juga dibuat minimalis

// https://bitbucket.org/christandlg/bmx280mi/src/master/examples/BMx280_I2C/BMx280_I2C.ino
// BMx280_I2C.ino
//
// shows how to use the BMP280 / BMx280 library with the sensor connected using I2C.
//
// Copyright (c) 2018 Gregor Christandl
//
// connect the AS3935 to the Arduino like this:
//
// Arduino - BMP280 / BME280
// 3.3V ---- VCC
// GND ----- GND
// SDA ----- SDA
// SCL ----- SCL
// some BMP280/BME280 modules break out the CSB and SDO pins as well:
// 5V ------ CSB (enables the I2C interface)
// GND ----- SDO (I2C Address 0x76)
// 5V ------ SDO (I2C Address 0x77)
// other pins can be left unconnected.

#include <Arduino.h>
#include <Wire.h>

#define I2C_SDA 15
#define I2C_SCL 13

#include <BMx280I2C.h>

#define I2C_ADDRESS 0x76

//create a BMx280I2C object using the I2C interface with I2C Address 0x76
BMx280I2C bmx280(I2C_ADDRESS);

void setup() {
  // put your setup code here, to run once:
  Serial.begin(9600);
  delay(1000);

  //wait for serial connection to open (only necessary on some boards)
  while (!Serial);

  //  Wire.begin();
  Wire.begin(I2C_SDA, I2C_SCL);

  I2C_Scan() ; // just for verifying
  
  //begin() checks the Interface, reads the sensor ID (to differentiate between BMP280 and BME280)
  //and reads compensation parameters.
  if (!bmx280.begin())
  {
    Serial.println("begin() failed. check your BMx280 Interface and I2C Address.");
    while (1);
  }

  if (bmx280.isBME280())
    Serial.println("sensor is a BME280");
  else
    Serial.println("sensor is a BMP280");

  //reset sensor to default parameters.
  bmx280.resetToDefaults();

  //by default sensing is disabled and must be enabled by setting a non-zero
  //oversampling setting.
  //set an oversampling setting for pressure and temperature measurements.
  bmx280.writeOversamplingPressure(BMx280MI::OSRS_P_x16);
  bmx280.writeOversamplingTemperature(BMx280MI::OSRS_T_x16);

  //if sensor is a BME280, set an oversampling setting for humidity measurements.
  if (bmx280.isBME280())
    bmx280.writeOversamplingHumidity(BMx280MI::OSRS_H_x16);
}

void loop() {
  float temperature = 0;
  float pressure = 0;
  float humidity = 60; // default humidity
  float co2 = 0;
  float tvoc = 0;

  delay(1000);

  //start a measurement
  if (!bmx280.measure())
  {
    Serial.println("could not start measurement, is a measurement already running?");
    return;
  }

  //wait for the measurement to finish
  do
  {
    delay(100);
  } while (!bmx280.hasValue());

  //  Serial.print("Pressure: "); Serial.println(bmx280.getPressure());
  //  Serial.print("Pressure (64 bit): "); Serial.println(bmx280.getPressure64());
  //  Serial.print("Temperature: "); Serial.println(bmx280.getTemperature());

  pressure = bmx280.getPressure();
  temperature = bmx280.getTemperature();

  //important: measurement data is read from the sensor in function hasValue() only.
  //make sure to call get*() functions only after hasValue() has returned true.
  if (bmx280.isBME280())
  {
    //    Serial.print("Humidity: ");
    //    Serial.println(bmx280.getHumidity());
    humidity = bmx280.getHumidity();
  }

  Serial.print("Temp\t");
  Serial.print(temperature);
  Serial.print("\t");
  Serial.print("Humidity\t");
  Serial.print(humidity);
  Serial.print("\t");
  Serial.print("Pressure\t");
  Serial.print(pressure);
  Serial.print("\t");
  Serial.println("");
}

void I2C_Scan() {
  byte error, address;

  int nDevices;
  Serial.println("I2C Scanning...");
  nDevices = 0;
  for (address = 1; address < 127; address++ ) {
    Wire.beginTransmission(address);
    error = Wire.endTransmission();
    if (error == 0) {
      Serial.print("I2C device found at address 0x");
      if (address < 16) {
        Serial.print("0");
      }
      Serial.println(address, HEX);
      nDevices++;
    }
    else if (error == 4) {
      Serial.print("Unknow error at address 0x");
      if (address < 16) {
        Serial.print("0");
      }
      Serial.println(address, HEX);
    }
  }
  if (nDevices == 0) {
    Serial.println("No I2C devices found\n");
  }
  else {
    Serial.println("done\n");
  }
}