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เช็ค MAC Address Node MCU

napster 
#include <ESP8266WiFi.h>
uint8_t MAC_array[6];
char MAC_char[18];
void setup() {
  Serial.begin(115200);
  Serial.println();
  WiFi.macAddress(MAC_array);
  for (int i = 0; i < sizeof(MAC_array); ++i) {
    sprintf(MAC_char, "%s%02x:", MAC_char, MAC_array[i]);
  }
  Serial.println(MAC_char);
}
void loop() {
  Serial.println(MAC_char);
  Serial.println();
  delay(5000);

#Ref.https://sites.google.com/site/moscash007/bth-thi-3-ip-address