Hello everyone, today I will show you my eighth experience with ESP32. In this project, I will use LED light and BMP280 as atmospheric pressure, temperature and relative humidity sensor. And I will use wi-fi for this project. Before we get into the tutorial, I will show you necessary items to build the system.
- ESP32
2. Micro USB Cable
3. Laptop/PC with Arduino IDE app installed
4. Male to male jumper cable
5. LED Light
6. Resistor 330 Ohm
7. BMP280
After you have all of this, you can start the project.
In this project you will need your wifi name/SSID and password. First, you need to arrange the breadboard like this :
In this project you will see the BMP280 result on a website and you will able to control LED light in the website. Of course, you will need this code for the ESP32 :
#include <Wire.h>
#include <WiFi.h>
#include <SPI.h>
#include <Adafruit_BMP280.h>
#define BMP_SCK (13)
#define BMP_MISO (12)
#define BMP_MOSI (11)
#define BMP_CS (10)Adafruit_BMP280 bmp; // I2C
//Adafruit_BMP280 bmp(BMP_CS); // hardware SPI
//Adafruit_BMP280 bmp(BMP_CS, BMP_MOSI, BMP_MISO, BMP_SCK);// Replace with your network credentials
const char* ssid = "xxxxxxxx";
const char* password = "xxxxxxxx";// Set web server port number to 80
WiFiServer server(80);
// Variable to store the HTTP request
String header;
// Auxiliar variables to store the current output state
String outputState = "off";
// Assign output variables to GPIO pins
const int output = 23;
// Current time
unsigned long currentTime = millis();
// Previous time
unsigned long previousTime = 0;
// Define timeout time in milliseconds (example: 2000ms = 2s)
const long timeoutTime = 2000;
void setup() {
Serial.begin(115200);
while ( !Serial ) delay(100); // wait for native usb
Serial.println(F("BMP280 test"));
unsigned status;
//status = bmp.begin(BMP280_ADDRESS_ALT, BMP280_CHIPID);
status = bmp.begin(0x76);
if (!status) {
Serial.println(F("Could not find a valid BMP280 sensor, check wiring or "
"try a different address!"));
Serial.print("SensorID was: 0x"); Serial.println(bmp.sensorID(),16);
Serial.print(" ID of 0xFF probably means a bad address, a BMP 180 or BMP 085\n");
Serial.print(" ID of 0x56-0x58 represents a BMP 280,\n");
Serial.print(" ID of 0x60 represents a BME 280.\n");
Serial.print(" ID of 0x61 represents a BME 680.\n");
while (1) delay(10);
}
/* Default settings from datasheet. */
bmp.setSampling(Adafruit_BMP280::MODE_NORMAL, /* Operating Mode. */
Adafruit_BMP280::SAMPLING_X2, /* Temp. oversampling */
Adafruit_BMP280::SAMPLING_X16, /* Pressure oversampling */
Adafruit_BMP280::FILTER_X16, /* Filtering. */
Adafruit_BMP280::STANDBY_MS_500); /* Standby time. */
// Initialize the output variables as outputs
pinMode(output, OUTPUT);
// Set outputs to LOW
digitalWrite(output, LOW);
// Connect to Wi-Fi network with SSID and password
Serial.print("Connecting to ");
Serial.println(ssid);
WiFi.begin(ssid, password);
while (WiFi.status() != WL_CONNECTED) {
delay(500);
Serial.print(".");
}
// Print local IP address and start web server
Serial.println("");
Serial.println("WiFi connected.");
Serial.println("IP address: ");
Serial.println(WiFi.localIP());
server.begin();
}
void loop() {
WiFiClient client = server.available(); // Listen for incoming clients
if (client) { // If a new client connects,
currentTime = millis();
previousTime = currentTime;
Serial.println("New Client."); // print a message out in the serial port
String currentLine = ""; // make a String to hold incoming data from the client
while (client.connected() && currentTime - previousTime <= timeoutTime) { // loop while the client's connected
currentTime = millis();
if (client.available()) { // if there's bytes to read from the client,
char c = client.read(); // read a byte, then
Serial.write(c); // print it out the serial monitor
header += c;
if (c == '\n') { // if the byte is a newline character
// if the current line is blank, you got two newline characters in a row.
// that's the end of the client HTTP request, so send a response:
if (currentLine.length() == 0) {
// HTTP headers always start with a response code (e.g. HTTP/1.1 200 OK)
// and a content-type so the client knows what's coming, then a blank line:
client.println("HTTP/1.1 200 OK");
client.println("Content-type:text/html");
client.println("Connection: close");
client.println();
// turns the GPIOs on and off
if (header.indexOf("GET /23/on") >= 0) {
Serial.println("LED on");
outputState = "on";
digitalWrite(output, HIGH);
} else if (header.indexOf("GET /23/off") >= 0) {
Serial.println("LED off");
outputState = "off";
digitalWrite(output, LOW);
}
// Display the HTML web page
client.println("<!DOCTYPE html><html>");
client.println("<head><meta name=\"viewport\" content=\"width=device-width, initial-scale=1\">");
client.println("<link rel=\"icon\" href=\"data:,\">");
// CSS to style the table
client.println("<style>body { text-align: center; font-family: \"Trebuchet MS\", Arial;}");
client.println("table { border-collapse: collapse; width:35%; margin-left:auto; margin-right:auto; }");
client.println("th { padding: 12px; background-color: #0043af; color: white; }");
client.println("tr { border: 1px solid #ddd; padding: 12px; }");
client.println("tr:hover { background-color: #bcbcbc; }");
client.println("td { border: none; padding: 12px; }");
client.println(".sensor { color:#FF0000; font-weight: bold; padding: 1px; }");
// CSS to style the on/off buttons
client.println("<style>html { font-family: Sans-serif; display: inline-block; margin: 0px auto; text-align: center;}");
client.println(".button { background-color: #0043af; border: none; color: white; padding: 16px 40px;");
client.println("text-decoration: none; font-size: 30px; margin: 2px; cursor: pointer;}");
client.println(".button2 {background-color: #ff0000;}</style></head>");
// Web Page Heading
client.println("</style></head><body><h1>Room Monitoring and Controlling System</h1>");
client.println("<table><tr><th>MEASUREMENT</th><th>VALUE</th></tr>");
client.println("<tr><td>Temperature on Celcius</td><td><span class=\"sensor\">");
client.println(bmp.readTemperature());
client.println(" *C</span></td></tr>");
client.println("<tr><td>Temperature on Fahrenheit</td><td><span class=\"sensor\">");
client.println(1.8 * bmp.readTemperature() + 32);
client.println(" *F</span></td></tr>");
client.println("<tr><td>Pressure</td><td><span class=\"sensor\">");
client.println(bmp.readPressure() / 100.0F);
client.println(" hPa</span></td></tr>");
client.println("<tr><td>Approximate Altitude</td><td><span class=\"sensor\">");
client.println(bmp.readAltitude(1013.25));
client.println(" m</span></td></tr>");
// Display current state, and ON/OFF buttons for GPIO 23
client.println("<p>Fan State " + outputState + "</p>");
if (outputState=="off") {
client.println("<p><a href=\"/23/on\"><button class=\"button\">ON</button></a></p>");
} else {
client.println("<p><a href=\"/23/off\"><button class=\"button button2\">OFF</button></a></p>");
}
client.println("</body></html>");
// The HTTP response ends with another blank line
client.println();
// Break out of the while loop
break;
} else { // if you got a newline, then clear currentLine
currentLine = "";
}
} else if (c != '\r') { // if you got anything else but a carriage return character,
currentLine += c; // add it to the end of the currentLine
}
}
}
// Clear the header variable
header = "";
// Close the connection
client.stop();
Serial.println("Client disconnected.");
Serial.println("");
}
}Don’t forget to change this part into your wifi name and password :
// Replace with your network credentials
const char* ssid = "xxxxxxxx";
const char* password = "xxxxxxxx";After you upload the code you need to open your serial monitor and press EN button on your ESP32, after you press the EN button you will see this on serial monitor:
Now, copy paste the IP address to your browser with the same wifi connection with ESP32. Click enter and you will see this :
This is the result if you press on button:
So, this is the end of my experience with ESP32 Wifi and also the end of my journey with ESP32 :( BUT don’t worry because I will make something more special with ESP32 in my final project, if possible, I will post it on my medium :) Anyway, Thank you for your attention.
Pavita Andrea (18220014)
