Serial number chips

Here's one way to get there:-

Best regards, Spehro Pefhany

What is your budget? Does it have to be 1-wire?

How about microchip

They had a MAC address chip EEPROM somewhere too.

Cheers

No need for 1-wire -- just serial number. I looked on DigiKey and only got Maxim stuff. I trust Microchip.

We've used 24AA02E48 from Microchip - EEPROM for settings and MAC address included.

I can't believe how cheap they are... $0.24 one off... excellent find!

NXP has a lot of this kind of stuff. Also wireless:

IIRC, the cost of buying a block of MAC addresses is > $1K, so it's a particularly good solution for relatively small quantities of devices requiring proper unique MAC addresses.

Best regards, Spehro Pefhany

You can save yourself the trouble. Many MAC address ranges belong to companies that are long gone or turned into patent trolls. Many people forget that the scope of a MAC address only goes as far as one ethernet segment. A MAC address is not a unique product number! When a manufacturer is at the end of the range, they just start at 0 and re-use all MAC addresses ad infinitum. The chance you end up with (for instance) 2 network cards with the same MAC address on one ethernet segment is almost zero.

Yup, an old Ethernet project may get revived because of this convenience. I think the Ieee had an issue with people buying blocks and selling individual MAC UI's This pretty much circumvents it.

Cheers