ESP8266 Community Forum

Posted: **Sat Feb 24, 2018 6:18 am**

I am a complete noob so please be gentle

I have a NodeMCU V3 and my first project is to try and build a weather station.

After reading a number of tutorials I decided that a BMP280 appeared to be a perfect component for my project as it can supply temperature, barometric pressure and humidity information.

I am using the following example sketch:

Code: Select all

/*********
  Project: BME Weather Web server using NodeMCU
  Implements Adafruit's sensor libraries.
  Complete project is at: http://embedded-lab.com/blog/making-a-simple-weather-web-server-using-esp8266-and-bme280/
  
  Modified code from Rui Santos' Temperature Weather Server posted on http://randomnerdtutorials.com  
*********/

#include <Wire.h>
#include <ESP8266WiFi.h>
#include <Adafruit_Sensor.h>
#include <Adafruit_BME280.h>

Adafruit_BME280 bme; // I2C

// Replace with your network details
const char* ssid = "SKY3E915";
const char* password = "thisisnotmypassword";
float h, t, p, pin, dp;
char temperatureFString[6];
char dpString[6];
char humidityString[6];
char pressureString[7];
char pressureInchString[6];

// Web Server on port 80
WiFiServer server(80);

// only runs once on boot
void setup() {
  // Initializing serial port for debugging purposes
  Serial.begin(115200);
  delay(10);
  Wire.begin(D3, D4);
  Wire.setClock(100000);
  // Connecting to WiFi network
  Serial.println();
  Serial.print("Connecting to ");
  Serial.println(ssid);
  
  WiFi.begin(ssid, password);
  
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }
  Serial.println("");
  Serial.println("WiFi connected");
  
  // Starting the web server
  server.begin();
  Serial.println("Web server running. Waiting for the ESP IP...");
  delay(10000);
  
  // Printing the ESP IP address
  Serial.println(WiFi.localIP());
  Serial.println(F("BME280 test"));

  if (!bme.begin()) {
    Serial.println("Could not find a valid BME280 sensor, check wiring!");
    while (1);
  }
}

void getWeather() {
  
    h = bme.readHumidity();
    t = bme.readTemperature();
    t = t*1.8+32.0;
    dp = t-0.36*(100.0-h);
    
    p = bme.readPressure()/100.0F;
    pin = 0.02953*p;
    dtostrf(t, 5, 1, temperatureFString);
    dtostrf(h, 5, 1, humidityString);
    dtostrf(p, 6, 1, pressureString);
    dtostrf(pin, 5, 2, pressureInchString);
    dtostrf(dp, 5, 1, dpString);
    delay(100);
 
}

// runs over and over again
void loop() {
  // Listenning for new clients
  WiFiClient client = server.available();
  
  if (client) {
    Serial.println("New client");
    // bolean to locate when the http request ends
    boolean blank_line = true;
    while (client.connected()) {
      if (client.available()) {
        char c = client.read();
        
        if (c == '\n' && blank_line) {
            getWeather();
            client.println("HTTP/1.1 200 OK");
            client.println("Content-Type: text/html");
            client.println("Connection: close");
            client.println();
            // your actual web page that displays temperature
            client.println("<!DOCTYPE HTML>");
            client.println("<html>");
            client.println("<head><META HTTP-EQUIV=\"refresh\" CONTENT=\"15\"></head>");
            client.println("<body><h1>ESP8266 Weather Web Server</h1>");
            client.println("<table border=\"2\" width=\"456\" cellpadding=\"10\"><tbody><tr><td>");
            client.println("<h3>Temperature = ");
            client.println(temperatureFString);
            client.println("&deg;F</h3><h3>Humidity = ");
            client.println(humidityString);
            client.println("%</h3><h3>Approx. Dew Point = ");
            client.println(dpString);
            client.println("&deg;F</h3><h3>Pressure = ");
            client.println(pressureString);
            client.println("hPa (");
            client.println(pressureInchString);
            client.println("Inch)</h3></td></tr></tbody></table></body></html>");  
            break;
        }
        if (c == '\n') {
          // when starts reading a new line
          blank_line = true;
        }
        else if (c != '\r') {
          // when finds a character on the current line
          blank_line = false;
        }
      }
    }  
    // closing the client connection
    delay(1);
    client.stop();
    Serial.println("Client disconnected.");
  }
}

I have connected SDA to D3 and SCL to D4 and it just reports that it cannot find the sensor.

Can anyone offer any help please? It would be very much appreciated!

Trev

Posted: **Sun Feb 25, 2018 3:42 am**

The BMP280 and BME280 are not the same. The BMP280 does not measure humidity. First, make clear which one you have! Choose the right library. Then try the addresses 0x76 and 0x77

Code: Select all

if (!bme.begin(0x76)) {
    Serial.println("Could not find a valid BME280 sensor, check wiring!");
    while (1);
  }

or

Code: Select all

if (!bme.begin(0x77)) {
    Serial.println("Could not find a valid BME280 sensor, check wiring!");
    while (1);
  }

ESP8266 Community Forum

NodeMCU V3 and BME280

NodeMCU V3 and BME280

Re: NodeMCU V3 and BME280