ESP32 Receiver

#include <esp_now.h>
#include <WiFi.h>

void onReceive(const uint8_t *mac_addr, const uint8_t *data, int data_len) {
  char message[data_len + 1];
  memcpy(message, data, data_len);
  message[data_len] = '\0';
  Serial.print("Message received: ");
  Serial.println(message);
}

void setup() {
  Serial.begin(115200);
  WiFi.mode(WIFI_STA);

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

  esp_now_register_recv_cb(onReceive);
}

void loop() {
  // Nothing to do here, everything is handled in the callback
}