Digital ID Tag Available?

Something like iButton?

I used these for this sort of thing successfully.

Andrew

Not really cheap, if all you need is an additional IC with a connection to a microcontroller. All 1-wire devices have a unique id:

The cheapest might be the DS2411, which has the unique id, only. If you can make some use of an external temperature sensor etc., one of the other devices might be useful.

Some microcontrollers nowadays have integrate unique ids, e.g. like the STM32 series.

The trivial solution is DS2401.

Many of the large flash memory ICs have the unique ID register. If you are using an external flash, that could be an option.

Vladimir Vassilevsky DSP and Mixed Signal Design Consultant

I think the 1-wire option may be perfect for the application.

Thank you very much!

You may use the Microchip serial 1-Wire EEProm with Pre-programmed Globally Unique, 48-bit Node Address. See documentation:

Konstantin Vovk

Depending how secure you want the id a low cost processor like one of the 8 bit Microchip PICs or a RS08 might also be workable solution.

Regards,

-- Walter Banks Byte Craft Limited

eeboarder wrote:

Check the price on the 1-wire stuff. They are a bit high considering what you are getting. Like others have said, there are generic EEPROM parts that will do the same thing, are cheaper and give you some memory for customizations of your own.

Rick

The DS2401 is around $1 which is well within the budget. I'm not going to do a multi-drop setup, so the electronics to get it up shouldn't be difficult. I'm still looking into it.

Requires just one uC pin, and DalSemi 1-wire stuff is easy to bit-bang. I wrote my own code for a DS1820 (only my second try at writing PIC I/O; first try was the obligatory hello-world flashing LED), which worked right off. Later I found 1-wire code all over the web.