Hi,

I have two esp32 talking one two each other. Because i do not know in advance the MAC address of each, i put on each of them the same MAC address at start.

Now i want to change with the real MAC address of the two ESP i have, but i do not know which is the receiver MAC and the sendre MAC. I will attach the little code from one so you can pinpoint where is sender MAC and and where is Receiver MAC. Here is the piece of code :

// send data
bool sendData(char *Data, int Length) {
char macStr[19];
snprintf(macStr, sizeof(macStr), “%02x:%02x:%02x:%02x:%02x:%02x”,
KeypadMAC[0], KeypadMAC[1], KeypadMAC[2], KeypadMAC[3], KeypadMAC[4], KeypadMAC[5]);
//const uint8_t *peer_addr = slave.peer_addr;
Serial.print(“Sending: “); Serial.print(Data); Serial.print(” To “); Serial.println(macStr);

esp_err_t result = esp_now_send(KeypadMAC, (uint8_t *)Data, Length);//strlen(Data));
Serial.print(“Send Status: “);
if (result == ESP_OK) {
Serial.println(“Success”);
} else if (result == ESP_ERR_ESPNOW_NOT_INIT) {
// How did we get so far!!
Serial.println(“ESPNOW not Init.”);
} else if (result == ESP_ERR_ESPNOW_ARG) {
Serial.println(“Invalid Argument”);
} else if (result == ESP_ERR_ESPNOW_INTERNAL) {
Serial.println(“Internal Error”);
} else if (result == ESP_ERR_ESPNOW_NO_MEM) {
Serial.println(“ESP_ERR_ESPNOW_NO_MEM”);
} else if (result == ESP_ERR_ESPNOW_NOT_FOUND) {
Serial.println(“Peer not found.”);
} else {
Serial.println(“Not sure what happened”);
}
if (result == ESP_OK) return true; else return false;
}

// callback when data is recv from Master
void OnDataRecv(const uint8_t *mac_addr, const uint8_t *data, int data_len)
{
char macStr[18];
uint16_t CommandLength;

snprintf(macStr, sizeof(macStr), “%02x:%02x:%02x:%02x:%02x:%02x”,
mac_addr[0], mac_addr[1], mac_addr[2], mac_addr[3], mac_addr[4], mac_addr[5]);
//Serial.print(“Last Packet Recv from: “); Serial.println(macStr);
//Serial.print(“Last Packet Recv Data: “); Serial.println(*data);
//Serial.print(” of data length “); Serial.println(data_len);
Serial.print(“data: “);
Serial.println((char *)data);
//Check for command or initial invitation
if (strstr((char *)data, “Keypad is here”) != NULL) {
doConnect = true;
doConfirmed = false;
Step = 0;
Serial.println(“Get invitation”);
} else if (strstr((char *)data, “Code received”) != NULL) {
doConfirmed = true;
} else {
//Decoding the command
CommandLength = Decode((char *)data, (size_t)data_len, Command);
Serial.print(“Decoded “), Serial.print(CommandLength); Serial.print(“: “); Serial.println(Command);
HaveCommand = true;
}
}

//Encryption …….

Thank you