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[on:]

Hi,

Is there any form of unique Identifier on an arduino mega processor (something that can be accessed programatically) ? I want to build a dozen identical arduino units, each running the same software, but each with a different ID. At the moment I change a single line in my code each time I upload, but this relies on me remembering to make the change, and loading the right ID into the correct arduino. I guess what I'm looking for is something like this....
if serial_number = 1234 then
    ID = A
if serial_number = 5678 then
    ID = B
etc etc.....

Any suggestions?

Regards

[Reply #1 on:]

EEPROM

[Reply #2 on:]

Is there any form of unique Identifier on an arduino mega processor

No, you have to make one like suggested above.

[Reply #3 on:]

Well AVR chips do have 'signature bytes' that are unique to the chip type and AVRDUDE can read them, but I have no idea if one can read those bytes at run time to determine what chip type the code is running on.

Lefty

[Reply #4 on:]

Unique to chip type, but are they unique to chip?

[Reply #5 on:]

Unique to chip type, but are they unique to chip?

No of course not, so not a solution to the OP's requirement. But as he was already told EEPROM allows a pretty straight forward solution.

However my question still stands, can a sketch program be made to read the chip's signature bytes?

Lefty

[Reply #6 on:]

No you can only read them in programming mode, page 298 of the data sheet.

[Reply #7 on:]

No you can only read them in programming mode, page 298 of the data sheet.

OK, thanks for that.

Lefty

[Reply #8 on:]

Lefty,
I see you have gone back to your old picture, that clip from the end of Dr. Strangelove.   

[Reply #9 on:]

A solution might be to add a one-wire device, these all have a 64 bit unique ID, - http://www.maxim-ic.com/products/1-wire/ -

[Reply #10 on:]

Lefty,
I see you have gone back to your old picture, that clip from the end of Dr. Strangelove.  

Yes, last night they crowned a new Baseball World Series Champion for 2011, so time to revert back.  

[Reply #11 on:]

'World Series'?
Who got invited to that?

[Reply #12 on:]

'World Series'?
Who got invited to that?

Why the whole world got invited, but only one country showed up.

[Reply #13 on:]

'World Series', after all these years I still get a laugh out of that.

Re the unique ID, if you can handle the (very slight) possibility of having duplicates you can generate a random number (I think we should start a thread about generating random numbers ) on power up and burn that into EEPROM at run time.

If they absolutely have to be unique then you'll have to run a counter on your PC and burn it from there.

______
Rob 

[Reply #14 on:]

'World Series'?
Who got invited to that?

Canada and half the players these days are from Latin America.