ESP32_DEVKIT_sender_esp_now.ino

ESP32_DEVKIT_sender_esp_now.ino

/*
  Florin Simedru
  Complete project details at https://automatic-house.blogspot.com
  
  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.
*/

/********************************************************************************************************************
 *  Preferences--> Aditional boards Manager URLs : https://dl.espressif.com/dl/package_esp32_index.json, http://arduino.esp8266.com/stable/package_esp8266com_index.json
 *  Board Settings:
 *  Board: "ESP32 Wrover Module"
 *  Upload Speed: "921600"
 *  Flash Frequency: "80MHz"
 *  Flash Mode: "QIO"
 *  Partition Scheme: "Hue APP (3MB No OTA/1MB SPIFFS)"
 *  Core Debug Level: "None"
 *  COM Port: Depends *On Your System*
 *  
 */

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

// REPLACE WITH YOUR RECEIVER MAC Address
uint8_t broadcastAddress[] = {0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF};

// Insert your SSID
constexpr char WIFI_SSID[] = "YOURWIFI_SSID";

// Structure example to send data
// Must match the receiver structure
typedef struct struct_message {
  char a[32];
  int b;
  float c;
  bool d;
} struct_message;

// Create a struct_message called myData
struct_message myData;

// callback when data is sent
void OnDataSent(const uint8_t *mac_addr, esp_now_send_status_t status) {
  Serial.print("\r\nLast Packet Send Status:\t");
  Serial.println(status == ESP_NOW_SEND_SUCCESS ? "Delivery Success" : "Delivery Fail");
}

int32_t getWiFiChannel(const char *ssid) {
  if (int32_t n = WiFi.scanNetworks()) {
      for (uint8_t i=0; i<n; i++) {
          if (!strcmp(ssid, WiFi.SSID(i).c_str())) {
              return WiFi.channel(i);
          }
      }
  }
  return 0;
}
 
void setup() {
  // Init Serial Monitor
  Serial.begin(115200);
  // Set device as a Wi-Fi Station
  WiFi.mode(WIFI_MODE_STA);
  Serial.println(WiFi.macAddress());
  
  int32_t channel = getWiFiChannel(WIFI_SSID);
  esp_wifi_set_channel(channel, WIFI_SECOND_CHAN_NONE);
  
  // Init ESP-NOW
  if (esp_now_init() != ESP_OK) {
    Serial.println("Error initializing ESP-NOW");
    return;
  }

  // Once ESPNow is successfully Init, we will register for Send CB to
  // get the status of Trasnmitted packet
  esp_now_register_send_cb(OnDataSent);
  
  // Register peer
  esp_now_peer_info_t peerInfo;
  memcpy(peerInfo.peer_addr, broadcastAddress, 6);
  peerInfo.channel = 0;  
  peerInfo.encrypt = false;
  
  // Add peer        
  if (esp_now_add_peer(&peerInfo) != ESP_OK){
    Serial.println("Failed to add peer");
    return;
  }
}
 
void loop() {
  // Set values to send
  strcpy(myData.a, "THIS IS A CHAR");
  myData.b = random(1,20);
  myData.c = 1.2;
  myData.d = false;
  
  // Send message via ESP-NOW
  esp_err_t result = esp_now_send(broadcastAddress, (uint8_t *) &myData, sizeof(myData));
   
  if (result == ESP_OK) {
    Serial.println("Sent with success");
  }
  else {
    Serial.println("Error sending the data");
  }
  delay(2000);
}