MACAddress

Genuino/Arduino Library to generate and operate on and with MAC addresses.

The original purpose was to use it in a sort of massive firmware project on a MEGA or a Nano where a few customizations were to be automatically accomplished based on dynamic and static IP addresses assignments.

#include <Arduino.h>
#include <Ethernet.h>
#include <IPAddress.h>

#include <MACAddress.h>

const uint32_t BAUD_RATE{115200};

void setup(void) {
  Serial.begin(BAUD_RATE);
  MACAddress mac{0xCA, 0xFE, 0xBA, 0xBE, 0, 0x01};

  Serial.print("Current MAC Address is ");

  if(0 == Ethernet.begin(mac)) {
    Serial.println(mac);
    Serial.println("The DHCP server has assigned an IP Address.")
  } else {
    IPAddress ip{192, 168, 1, 234};

    for(auto i = 0; i != 4; ++i)
      mac[2 + i] = ip[i];

    Serial.println(mac);

    Ethernet.begin(mac, ip);

    Serial.print("A static IP Address (");
    Serial.print(mac);
    Serial.print('/');
    Serial.print(ip);
    Serial.println(") configuration has been tried.");
  }
}

void loop(void) {}

The main class then evolved on its own and now supports initialization from array of chars, ints, strings besides single octets.

MACAddress mac0{F("0:8:ab:cd:0:3")};

char c_octets[]{"10:::34::87"};
MACAddress mac1{c_octets};

String s{"AB:cd::::64"};
MACAddress mac2{s};

int octets[]{0xC0, 0xFF, 0xEE, 0xD0, 0x00, 0xFF};
MACAddress mac3{octets};

A MACAddress object can be easily casted to an array of ints, printed to streams, converted to chars according to common usage and EUI-48 specifications, and even produce a compact array of chars whenever possible and requested (in case of leading zeros or zeroed octets).

Serial.print("mac0: ");
Serial.print(mac0.c_str(Representation::COMMON_FULL));
Serial.print(" == ");
Serial.print(mac0.c_str(Representation::COMMON_COMPACT));
Serial.print(" == ");
Serial.println(mac0.c_str(Representation::EUI48));

Single octets may be changed at any time by using the array notation; the extension id may be easily requested and set according to the 24, 28 and 36 bits length and a few operations such as comparisons for equality and inequality, addition and subtraction are supported.

The library may be larger than probably most of us would ever need, but in some cases it can be really helpful not to worry about conversions, memory allocation or whatever.

Any feedback on it and on its usage is and will always be greatly appreciated.