#include <SoftwareSerial.h>

SoftwareSerial espSerial(3, 4);  // ESP8266 TX -> D3, RX -> D4 (via voltage divider)

const char* SSID = "Your_WiFi_Name";       // Change to your Wi-Fi SSID
const char* PASSWORD = "Your_WiFi_Password"; // Change to your Wi-Fi Password
const char* CHANNEL_ID = "Your_Channel_ID"; // Change to your ThingSpeak Channel ID
const char* API_KEY = "Your_ThingSpeak_API_Key"; // Change to your ThingSpeak Read API Key

void setup() {
    Serial.begin(9600);
    espSerial.begin(115200);
    Serial.println("Connecting to WiFi...");
    connectToWiFi();
}

void loop() {
    Serial.println("Retrieving data from ThingSpeak...");
    fetchDataFromThingSpeak();
    delay(15000);  // Fetch data every 15 seconds
}

void connectToWiFi() {
    espSerial.println("AT+RST");
    delay(2000);
    espSerial.println("AT+CWMODE=1");
    delay(2000);

    String cmd = "AT+CWJAP=\"" + String(SSID) + "\",\"" + String(PASSWORD) + "\"";
    espSerial.println(cmd);
    delay(5000);

    Serial.println("WiFi Connected!");
}

void fetchDataFromThingSpeak() {
    String cmd = "AT+CIPSTART=\"TCP\",\"api.thingspeak.com\",80";
    espSerial.println(cmd);
    delay(2000);

    String request = "GET /channels/" + String(CHANNEL_ID) + "/feeds/last.json?api_key=" + String(API_KEY);
    cmd = "AT+CIPSEND=" + String(request.length() + 2);
    espSerial.println(cmd);
    delay(2000);

    espSerial.println(request);
    delay(2000);

    Serial.println("Data Retrieved:");
    while (espSerial.available()) {
        Serial.write(espSerial.read());
    }

    espSerial.println("AT+CIPCLOSE");
    delay(2000);
}