/*
Rui Santos
Complete project details at https://RandomNerdTutorials.com/esp32-client-server-wi-fi/
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files.
The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.
*/
#include <WiFi.h>
#include <HTTPClient.h>
const char* ssid = "ESP32-Access-Point";
const char* password = "123456789";
//Your IP address or domain name with URL path
const char* serverNameTemp = "http://192.168.4.1/temperature";
const char* serverNameHumi = "http://192.168.4.1/humidity";
const char* serverNamePres = "http://192.168.4.1/pressure";
#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>
#define SCREEN_WIDTH 128 // OLED display width, in pixels
#define SCREEN_HEIGHT 64 // OLED display height, in pixels
// Declaration for an SSD1306 display connected to I2C (SDA, SCL pins)
#define OLED_RESET 4 // Reset pin # (or -1 if sharing Arduino reset pin)
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET);
String temperature;
String humidity;
String pressure;
unsigned long previousMillis = 0;
const long interval = 5000;
void setup() {
Serial.begin(115200);
// Address 0x3C for 128x64, you might need to change this value (use an I2C scanner)
if(!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) {
Serial.println(F("SSD1306 allocation failed"));
for(;;); // Don't proceed, loop forever
}
display.clearDisplay();
display.setTextColor(WHITE);
//WiFi.begin(ssid, password);
WiFi.begin("Wokwi-GUEST", "", 6);
Serial.println("Connecting");
while(WiFi.status() != WL_CONNECTED) {
delay(500);
Serial.print(".");
}
Serial.println("");
Serial.print("Connected to WiFi network with IP Address: ");
Serial.println(WiFi.localIP());
}
void loop() {
unsigned long currentMillis = millis();
if(currentMillis - previousMillis >= interval) {
// Check WiFi connection status
if(WiFi.status()== WL_CONNECTED ){
temperature = httpGETRequest(serverNameTemp);
humidity = httpGETRequest(serverNameHumi);
pressure = httpGETRequest(serverNamePres);
Serial.println("Temperature: " + temperature + " *C - Humidity: " + humidity + " % - Pressure: " + pressure + " hPa");
display.clearDisplay();
// display temperature
display.setTextSize(2);
display.setTextColor(WHITE);
display.setCursor(0,0);
display.print("T: ");
display.print(temperature);
display.print(" ");
display.setTextSize(1);
display.cp437(true);
display.write(248);
display.setTextSize(2);
display.print("C");
// display humidity
display.setTextSize(2);
display.setCursor(0, 25);
display.print("H: ");
display.print(humidity);
display.print(" %");
// display pressure
display.setTextSize(2);
display.setCursor(0, 50);
display.print("P:");
display.print(pressure);
display.setTextSize(1);
display.setCursor(110, 56);
display.print("hPa");
display.display();
// save the last HTTP GET Request
previousMillis = currentMillis;
}
else {
Serial.println("WiFi Disconnected");
}
}
}
String httpGETRequest(const char* serverName) {
WiFiClient client;
HTTPClient http;
// Your Domain name with URL path or IP address with path
http.begin(client, serverName);
// Send HTTP POST request
int httpResponseCode = http.GET();
String payload = "--";
if (httpResponseCode>0) {
Serial.print("HTTP Response code: ");
Serial.println(httpResponseCode);
payload = http.getString();
}
else {
Serial.print("Error code: ");
Serial.println(httpResponseCode);
}
// Free resources
http.end();
return payload;
}