ESP32 Arduino-ide how to get unique id - arduino

Question

I'm trying to set a unique id to each esp32 automatically. Before I was programming the devices using the ESP-IDF Framework that provides the method
esp_efuse_mac_get_default() this will return a 8 byte value unique over all devices I had my hands on.
In the arduino ide all I see is the ESP.getEfuseMac() method. This only returns 6 bytes and is the same for all devices of the same batch (?).
Is there any way I can get a 8 byte UUID on a ESP32?
Libraries like ArduinoUniqueID also use the ESP.getEfuseMac() and thus are not usable.

Answer 1

getEfuseMac returns a 64 bit integer.
uint64_t EspClass::getEfuseMac(void)
{
uint64_t _chipmacid = 0LL;
esp_efuse_mac_get_default((uint8_t*) (&_chipmacid));
return _chipmacid;
}
It should return it's MAC address which is unique to all esp.
On the ESP32 both ESP.getEfuseMac() and ESP.getChipId() returns the same MAC address.
Test it with:
Serial.printf("\nCHIP MAC: %012llx\n", ESP.getEfuseMac());
Serial.printf("\nCHIP MAC: %012llx\n", ESP.getChipId());
Or you could do this:
uint32_t low = ESP.getEfuseMac() & 0xFFFFFFFF;
uint32_t high = ( ESP.getEfuseMac() >> 32 ) % 0xFFFFFFFF;
uint64_t fullMAC = word(low,high);
Serial.printf("Low: %d\n",low);
Serial.printf("High: %d\n",high);
Serial.printf("Full: %d\n",fullMAC);
You can also use IDF functions in Arduino because it was built on it.
Check this:
void print_mac(const unsigned char *mac) {
printf("%02X:%02X:%02X:%02X:%02X:%02X\n", mac[0],mac[1],mac[2],mac[3],mac[4],mac[5]);
}
void macTest(){
unsigned char mac_base[6] = {0};
esp_efuse_mac_get_default(mac_base);
esp_read_mac(mac_base, ESP_MAC_WIFI_STA);
unsigned char mac_local_base[6] = {0};
unsigned char mac_uni_base[6] = {0};
esp_derive_local_mac(mac_local_base, mac_uni_base);
printf("Local Address: ");
print_mac(mac_local_base);
printf("\nUni Address: ");
print_mac(mac_uni_base);
printf("MAC Address: ");
print_mac(mac_base);
}
void setup(){
Serial.begin(115200);
delay(500);
macTest();
}