Networking & Communications

// Shared struct — identical on TX and RX sides
typedef struct struct_message {
  float temp;       // °C from OpenWeatherMap
  int   humidity;   // % relative humidity
  char  state[20];  // "Sunny", "Cloudy", "Rain", "Unknown"
} struct_message;

struct_message weatherData;

#include <WiFi.h>
#include <HTTPClient.h>
#include <ArduinoJson.h>
#include <esp_now.h>
#include <esp_wifi.h>

// WiFi (for internet only)
const char* ssid = "STARLINK";
const char* password = "InnovationS";

// OpenWeatherMap API
String apiKey = "dc1d744dcedcfc32de5d6f15c8d0f1b0";
String city = "Kigali";
String country = "rw";

// YOUR RECEIVER MAC ADDRESS
uint8_t receiverMac[] = {0x64, 0xE8, 0x33, 0x69, 0x69, 0x14};

// Data structure
typedef struct struct_message {
  float temp;
  int humidity;
  char state[20];
} struct_message;

struct_message weatherData;

esp_now_peer_info_t peerInfo;

// Convert weather → simple state
String getState(String w) {
  w.toLowerCase();

  if (w.indexOf("rain")  >= 0) return "Rain";
  if (w.indexOf("cloud") >= 0) return "Cloudy";
  if (w.indexOf("clear") >= 0) return "Sunny";

  return "Unknown";
}

void setup() {
  Serial.begin(115200);

  // Connect WiFi (for API only)
  WiFi.begin(ssid, password);
  Serial.print("Connecting WiFi");

  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }

  Serial.println("\nWiFi Connected!");

  // ESP-NOW init
  WiFi.mode(WIFI_STA);

  if (esp_now_init() != ESP_OK) {
    Serial.println("ESP-NOW Init Failed");
    return;
  }

  memcpy(peerInfo.peer_addr, receiverMac, 6);
  peerInfo.channel = 0;
  peerInfo.encrypt = false;

  if (esp_now_add_peer(&peerInfo) != ESP_OK) {
    Serial.println("Failed to add peer");
    return;
  }

  Serial.println("ESP-NOW Ready");
}

void loop() {

  if (WiFi.status() == WL_CONNECTED) {

    HTTPClient http;

    String url = "https://api.openweathermap.org/data/2.5/weather?q=" +
                 city + "," + country +
                 "&units=metric&appid=" + apiKey;

    http.begin(url);

    int httpCode = http.GET();

    if (httpCode > 0) {

      String payload = http.getString();

      DynamicJsonDocument doc(2048);
      DeserializationError error = deserializeJson(doc, payload);

      if (!error) {

        float temp    = doc["main"]["temp"];
        int   hum     = doc["main"]["humidity"];
        String weather = doc["weather"][0]["main"];

        weatherData.temp     = temp;
        weatherData.humidity = hum;

        String state = getState(weather);
        state.toCharArray(weatherData.state, 20);

        // Send via ESP-NOW
        esp_now_send(receiverMac, (uint8_t *)&weatherData, sizeof(weatherData));

        Serial.println("Sent:");
        Serial.print("Temp: ");  Serial.println(temp);
        Serial.print("Hum: ");   Serial.println(hum);
        Serial.print("State: "); Serial.println(state);
        Serial.println("------------------");
      }
    }

    http.end();
  }

  delay(60000); // update every 60 seconds
}