How can I find mac address?

I use "Arduino MEGA" & "Arduino ETHERNET Shield".

I called Ethernet.begin(), but no response. Why? I want to confirm the mac address. How can I find mac address?

I think you have to give it a MAC address. See the example here: http://arduino.cc/en/Reference/EthernetBegin

Hi, Groove

Sorry, insufficient explanation.

Mac address and Ip was setting. byte mac[] = { 0xXX, 0xXX, 0xXX, 0xXX, 0xXX, 0xXX }; byte ip[] = { 192, 168, 0, X };

I called Ethernet.begin(mac, ip), but no response. Why?

Therefore, I want to confirm the mac address. How can I find mac address?

What do you mean "no response"? Do you mean the sketch hung at that point?

Have you tried a "ping" to the device?

Hi, Groove!

Do you mean the sketch hung at that point?

digitalWrite( LED_RED7, HIGH ); <---- OK
Ethernet.begin(mac, ip);
delay( 200 );
digitalWrite( LED_RED7, LOW ); <---- NG

If…
digitalWrite( LED_RED7, HIGH ); <---- OK
//Ethernet.begin(mac, ip);
delay( 200 );
digitalWrite( LED_RED7, LOW ); <---- OK

Have you tried a “ping” to the device?

Request timed out.

What occurred?

I has been understood to have to write the mac address by the program.

Thank you!