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I2C devices with unique identifiers.
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Roberto Waltman
Aug 10, 2012, 1:47:30 PM8/10/12
to
For a project I am working on, I would like to give boards fresh from
manufacturing a distinct "identity", before they are assigned a serial
number, or have a MAC address or IP address programmed, etc.
This could be provided by some devices, such as Maxim's DS2411
"Silicon serial number" ( with a "Unique, Factory-Lasered and Tested
64-Bit Registration Number" ) or DS18B20 temperature sensor, ( "has a
Unique 64-Bit Serial Code Stored in an On-Board ROM" )
Looking for the least expensive chip with such an ID, with an I2C
(preferred), SPI or 1-wire interface. Don't care what other
functionality that chip may have, I just want the unique ID.
A device that report its own serial number would be OK.
Any recommendations?
Thanks,
--
Roberto Waltman
[ Please reply to the group,
return address is invalid ]
Joe Chisolm
Aug 10, 2012, 3:47:39 PM8/10/12
to
24AA025E48 is I2C. They will run you about $0.23 in a SOT-23
package. Get them from Mouser,Digikey,Avnet or direct from Microchip.
Good news is you also get some EEPROM along with the MAC address.
--
Chisolm
Republic of Texas
Roberto Waltman
Aug 10, 2012, 5:36:56 PM8/10/12
to
Joe Chisolm wrote:
>> Looking for the least expensive chip with such an ID,
>> Looking for the least expensive chip with such an ID,
>I use the Microchip 25AA02E48 in several products.
Thanks, that's exactly what I need.
rickman
Aug 11, 2012, 6:35:23 PM8/11/12
to
On 8/10/2012 5:36 PM, Roberto Waltman wrote:
> Joe Chisolm wrote:
>>> Looking for the least expensive chip with such an ID,
>
>> I use the Microchip 25AA02E48 in several products.
>
> Thanks, that's exactly what I need.
> --
> Roberto Waltman
Dallas did a good job with the one wire parts in general and only using
> Joe Chisolm wrote:
>>> Looking for the least expensive chip with such an ID,
>
>> I use the Microchip 25AA02E48 in several products.
>
> Thanks, that's exactly what I need.
> --
> Roberto Waltman
one wire is a great thing. But they don't seem to be price competitive
for who knows what reason. I seem to recall the one wire part that is
the least expensive is one of their eeproms. I'm pretty sure it is lot
more than a quarter. Heck, sometimes it is cheaper to emulate a one
wire part with an MCU, but then you have to do your own serial number
programming!
Rick
Nico Coesel
Aug 11, 2012, 8:17:47 PM8/11/12
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--
Failure does not prove something is impossible, failure simply
indicates you are not using the right tools...
nico@nctdevpuntnl (punt=.)
--------------------------------------------------------------
Roberto Waltman
Aug 11, 2012, 10:02:58 PM8/11/12
to
Nico Coesel wrote:
>Nowadays a lot of MCUs come with a unique serial number.
I know of a few, such as NXP's LPC1311. But the processor in this
>Nowadays a lot of MCUs come with a unique serial number.
project does not have this feature. (Can not change that)
Leo Havmøller
Aug 12, 2012, 12:51:28 AM8/12/12
to
> For a project I am working on, I would like to give boards fresh from
> manufacturing a distinct "identity", before they are assigned a serial
> number, or have a MAC address or IP address programmed, etc.
Does the board have a flash? Then maybe you already have a 64-bit unique ID
> manufacturing a distinct "identity", before they are assigned a serial
> number, or have a MAC address or IP address programmed, etc.
available.
Leo Havmøller.
Roberto Waltman
Aug 13, 2012, 10:34:37 AM8/13/12
to
Leo Havm�ller wrote:
>Does the board have a flash? Then maybe you already have a 64-bit unique ID
>available.
Thanks, I am aware of those and no, the only flash is the CPU's
>Does the board have a flash? Then maybe you already have a 64-bit unique ID
>available.
internal memory.
WangoTango
Aug 13, 2012, 2:30:10 PM8/13/12
to
In article <TsOdnZ0rq-7G-LjN...@earthlink.com>, jchisolm6
@earthlink.net says...
I second the recommendation, I use both flavors of these guys a regular
basis. As easy to use as any serial EEPROM and cheap.
@earthlink.net says...
basis. As easy to use as any serial EEPROM and cheap.
Uwe Bonnes
Aug 14, 2012, 3:54:24 PM8/14/12
to
In comp.arch.embedded Roberto Waltman <use...@rwaltman.com> wrote:
> For a project I am working on, I would like to give boards fresh from
> manufacturing a distinct "identity", before they are assigned a serial
> number, or have a MAC address or IP address programmed, etc.
> This could be provided by some devices, such as Maxim's DS2411
> "Silicon serial number" ( with a "Unique, Factory-Lasered and Tested
> 64-Bit Registration Number" ) or DS18B20 temperature sensor, ( "has a
> Unique 64-Bit Serial Code Stored in an On-Board ROM" )
> Looking for the least expensive chip with such an ID, with an I2C
> (preferred), SPI or 1-wire interface. Don't care what other
> functionality that chip may have, I just want the unique ID.
> A device that report its own serial number would be OK.
> Any recommendations?
How about using a uC with built-in unique ID? E.g. STM32F?
> For a project I am working on, I would like to give boards fresh from
> manufacturing a distinct "identity", before they are assigned a serial
> number, or have a MAC address or IP address programmed, etc.
> This could be provided by some devices, such as Maxim's DS2411
> "Silicon serial number" ( with a "Unique, Factory-Lasered and Tested
> 64-Bit Registration Number" ) or DS18B20 temperature sensor, ( "has a
> Unique 64-Bit Serial Code Stored in an On-Board ROM" )
> Looking for the least expensive chip with such an ID, with an I2C
> (preferred), SPI or 1-wire interface. Don't care what other
> functionality that chip may have, I just want the unique ID.
> A device that report its own serial number would be OK.
> Any recommendations?
Bye
--
Uwe Bonnes b...@elektron.ikp.physik.tu-darmstadt.de
Institut fuer Kernphysik Schlossgartenstrasse 9 64289 Darmstadt
--------- Tel. 06151 162516 -------- Fax. 06151 164321 ----------
Smeghead
Aug 14, 2012, 4:35:51 PM8/14/12
to
That's very interesting info on the 24AA025E48. We currently use a
STm24cxx256 part on our boards both to store a MAC address (and a bunch of
other programming information). We bought a block of 4096 addresses from
the IEEE, but keeping track of them all and having to program each boardset
prior to use is something of a pain.
While we need far more than the 2kbits available on the 24AA025E48, it
might be very much worthwhile adding one just for the MAC. Reading the
datasheet, it looks as if this is a valid IEEE MAC address as microchip
have registered for an OUI. Given that and the low price of the parts, I
might well be pushing for one of these on the next rev of our board as it
cuts out a programming step.
Thanks for the info!
---------------------------------------
Posted through http://www.EmbeddedRelated.com
STm24cxx256 part on our boards both to store a MAC address (and a bunch of
other programming information). We bought a block of 4096 addresses from
the IEEE, but keeping track of them all and having to program each boardset
prior to use is something of a pain.
While we need far more than the 2kbits available on the 24AA025E48, it
might be very much worthwhile adding one just for the MAC. Reading the
datasheet, it looks as if this is a valid IEEE MAC address as microchip
have registered for an OUI. Given that and the low price of the parts, I
might well be pushing for one of these on the next rev of our board as it
cuts out a programming step.
Thanks for the info!
Posted through http://www.EmbeddedRelated.com
Roberto Waltman
Aug 14, 2012, 6:38:13 PM8/14/12
to
Uwe Bonnes wrote:
>How about using a uC with built-in unique ID? E.g. STM32F?
Valid for a new design. This is a respin of an existing product, and
>How about using a uC with built-in unique ID? E.g. STM32F?
the CPU (untouchable) does not have an ID.
Joe Chisolm
Aug 14, 2012, 8:33:56 PM8/14/12
to
On Tue, 14 Aug 2012 15:35:51 -0500, Smeghead wrote:
> That's very interesting info on the 24AA025E48. We currently use a
> STm24cxx256 part on our boards both to store a MAC address (and a bunch
> of other programming information). We bought a block of 4096 addresses
> from the IEEE, but keeping track of them all and having to program each
> boardset prior to use is something of a pain.
>
> While we need far more than the 2kbits available on the 24AA025E48, it
> might be very much worthwhile adding one just for the MAC. Reading the
> datasheet, it looks as if this is a valid IEEE MAC address as microchip
> have registered for an OUI. Given that and the low price of the parts, I
> might well be pushing for one of these on the next rev of our board as
> it cuts out a programming step.
>
> Thanks for the info!
>
[snip]
> That's very interesting info on the 24AA025E48. We currently use a
> STm24cxx256 part on our boards both to store a MAC address (and a bunch
> of other programming information). We bought a block of 4096 addresses
> from the IEEE, but keeping track of them all and having to program each
> boardset prior to use is something of a pain.
>
> While we need far more than the 2kbits available on the 24AA025E48, it
> might be very much worthwhile adding one just for the MAC. Reading the
> datasheet, it looks as if this is a valid IEEE MAC address as microchip
> have registered for an OUI. Given that and the low price of the parts, I
> might well be pushing for one of these on the next rev of our board as
> it cuts out a programming step.
>
> Thanks for the info!
>
It's trivial to use your own OUI with these parts. Just slam
yours in the 1st 3 bytes when you program the EMAC block
josephkk
Aug 16, 2012, 3:09:19 AM8/16/12
to
On Tue, 14 Aug 2012 18:38:13 -0400, Roberto Waltman <use...@rwaltman.com>
wrote:
>Uwe Bonnes wrote:
>>How about using a uC with built-in unique ID? E.g. STM32F?
>
>Valid for a new design. This is a respin of an existing product, and
>the CPU (untouchable) does not have an ID.
Wait a minute, they are doing a respin and the old uC is untouchable???
Hand them a flashlight and a crowbar. They are in dire need. Even in
aerospace and medical any respin is effectively a new design. New pass on
ALL qualifications.
?-)
wrote:
>Uwe Bonnes wrote:
>>How about using a uC with built-in unique ID? E.g. STM32F?
>
>Valid for a new design. This is a respin of an existing product, and
>the CPU (untouchable) does not have an ID.
Hand them a flashlight and a crowbar. They are in dire need. Even in
aerospace and medical any respin is effectively a new design. New pass on
ALL qualifications.
?-)
rickman
Aug 16, 2012, 6:59:28 PM8/16/12
to
spin, but they don't want to touch any code they don't have to. Using a
different MCU chip can wreak havoc on code if it turns out to have
unsuspected hardware dependencies.
"There's many a slip, twixt cup and lip."
Rick
Roberto Waltman
Aug 16, 2012, 10:19:49 PM8/16/12
to
rickman wrote:
>I understand that perfectly. I don't know why they are doing a board
>spin, but they don't want to touch any code they don't have to. Using a
>different MCU chip can wreak havoc on code if it turns out to have
>unsuspected hardware dependencies.
Precisely. The new and old boards share 80% of the peripherals, and
>I understand that perfectly. I don't know why they are doing a board
>spin, but they don't want to touch any code they don't have to. Using a
>different MCU chip can wreak havoc on code if it turns out to have
>unsuspected hardware dependencies.
that means a lot of the code is already written, tested and known to
be reliable, if we stay with the same CPU.
josephkk
Aug 17, 2012, 10:24:14 PM8/17/12
to
On Thu, 16 Aug 2012 22:19:49 -0400, Roberto Waltman <use...@rwaltman.com>
wrote:
>rickman wrote:
>>I understand that perfectly. I don't know why they are doing a board
>>spin, but they don't want to touch any code they don't have to. Using a
>>different MCU chip can wreak havoc on code if it turns out to have
>>unsuspected hardware dependencies.
>
>Precisely. The new and old boards share 80% of the peripherals, and
>that means a lot of the code is already written, tested and known to
>be reliable, if we stay with the same CPU.
Well alrighty then. Family compatible could be potentially acceptable
then. Depends a lot on just which peripherals are onboard the MCU.
?-)
wrote:
>rickman wrote:
>>I understand that perfectly. I don't know why they are doing a board
>>spin, but they don't want to touch any code they don't have to. Using a
>>different MCU chip can wreak havoc on code if it turns out to have
>>unsuspected hardware dependencies.
>
>Precisely. The new and old boards share 80% of the peripherals, and
>that means a lot of the code is already written, tested and known to
>be reliable, if we stay with the same CPU.
then. Depends a lot on just which peripherals are onboard the MCU.
?-)
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