Arduino atmega328p unique id/serial number

ReadMe.md

Purpose of this code is to read ID memory of the AVR processors with the aim to display its Lot ID and Wafer ID numbers. Usually, original chips have there reasonable numbers. Non-original chips contains FF here.

uid.ino

#include <avr/boot.h>

void print_val(char *msg, uint8_t val)
{
    Serial.print(msg);
    Serial.println(val, HEX);
}

void setup(void)
{

    Serial.begin(9600);
    while (!Serial) ;
#define SIGRD 5
#if defined(SIGRD) || defined(RSIG)
    Serial.print("Signature : ");
    for (uint8_t i = 0; i < 5; i += 2) {
        Serial.print(" 0x");
        Serial.print(boot_signature_byte_get(i), HEX);
    }
    Serial.println();

    Serial.print("Serial Number : ");
    for (uint8_t i = 14; i < 24; i += 1) {
        Serial.print(" 0x");
        Serial.print(boot_signature_byte_get(i), HEX);
    }
    Serial.println();
#endif
}