├── .gitattributes
└── ESPNOW_Many2Many
    └── ESPNOW_Many2Many.ino


/.gitattributes:
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1 | # Auto detect text files and perform LF normalization
2 | * text=auto
3 | 


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/ESPNOW_Many2Many/ESPNOW_Many2Many.ino:
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  1 | /*
  2 |  *  This is the code for Many To Many Communication using ESPNOW for ESP32
  3 |  * 
  4 |  * 
  5 |  * The Full tutorial video of this project is uploaded on our youtube channel 
  6 |  * 
  7 |  * https://www.youtube.com/techiesms
  8 |  * 
  9 |  */
 10 | 
 11 | #include <esp_now.h>
 12 | #include <WiFi.h>
 13 | 
 14 | #define but_on 13
 15 | #define but_off 12
 16 | #define LED 14
 17 | 
 18 | 
 19 | bool new_data = 0; // Flag to send data only once
 20 | 
 21 | 
 22 | // Universal MAC Address
 23 | uint8_t broadcastAddress[] = {0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF};
 24 | 
 25 | bool incomingLED_status;
 26 | 
 27 | // Structure example to send data
 28 | // Must match the receiver structure
 29 | typedef struct struct_message
 30 | {
 31 |   int but_status;
 32 | } struct_message;
 33 | 
 34 | // Create a struct_message called myData
 35 | struct_message myData;
 36 | 
 37 | struct_message incomingReadings;
 38 | // Create peer interface
 39 | esp_now_peer_info_t peerInfo;
 40 | 
 41 | // callback when data is sent
 42 | void OnDataSent(const uint8_t *mac_addr, esp_now_send_status_t status) {
 43 |   Serial.print("\r\nLast Packet Send Status:\t");
 44 |   Serial.println(status == ESP_NOW_SEND_SUCCESS ? "Delivery Success" : "Delivery Fail");
 45 | }
 46 | void OnDataRecv(const uint8_t * mac, const uint8_t *incomingData, int len) {
 47 |   memcpy(&incomingReadings, incomingData, sizeof(incomingReadings));
 48 |   Serial.print("Bytes received: ");
 49 |   Serial.println(len);
 50 |   incomingLED_status = incomingReadings.but_status;
 51 |   Serial.println(incomingReadings.but_status);
 52 |   digitalWrite(LED, incomingLED_status);
 53 | 
 54 | }
 55 | 
 56 | void setup() {
 57 |   // Init Serial Monitor
 58 |   Serial.begin(115200);
 59 |   pinMode(but_on, INPUT_PULLUP);
 60 |   pinMode(but_off, INPUT_PULLUP);
 61 |   pinMode(LED, OUTPUT);
 62 | 
 63 |   // Set device as a Wi-Fi Station
 64 |   WiFi.mode(WIFI_STA);
 65 | 
 66 |   // Init ESP-NOW
 67 |   if (esp_now_init() != ESP_OK) {
 68 |     Serial.println("Error initializing ESP-NOW");
 69 |     return;
 70 |   }
 71 | 
 72 |   // Send Callback Function
 73 |   esp_now_register_send_cb(OnDataSent);
 74 | 
 75 |   // Receive Callback Function
 76 |   esp_now_register_recv_cb(OnDataRecv);
 77 | 
 78 |   // Register peer
 79 |   memcpy(peerInfo.peer_addr, broadcastAddress, 6);
 80 |   peerInfo.channel = 0;
 81 |   peerInfo.encrypt = false;
 82 | 
 83 |   // Add peer
 84 |   if (esp_now_add_peer(&peerInfo) != ESP_OK) {
 85 |     Serial.println("Failed to add peer");
 86 |     return;
 87 |   }
 88 | }
 89 | 
 90 | void loop()
 91 | {
 92 |   // Set values to send
 93 |   if (digitalRead(but_on) == LOW && new_data == 1)
 94 |   {
 95 |     myData.but_status = 1;
 96 |     new_data = 0;
 97 |   }
 98 |   if (digitalRead(but_off) == LOW && new_data == 1)
 99 |   {
100 |     myData.but_status = 0;
101 |     new_data = 0;
102 |   }
103 | 
104 |   esp_err_t result; // declaration
105 | 
106 |   // Send message via ESP-NOW
107 |   if (new_data == 0)
108 |   {
109 | 
110 |     result = esp_now_send(broadcastAddress, (uint8_t *) &myData, sizeof(myData));
111 |     new_data = 1;
112 |   }
113 | 
114 |   if (result == ESP_OK) 
115 |   {
116 |     Serial.println("Sent with success");
117 |   }
118 |   else
119 |   {
120 |     Serial.println("Error sending the data");
121 |   }
122 | 
123 |   // delay(10000);
124 | }
125 | 


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