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Topic: Wiznet MAC address (Read 2835 times) previous topic - next topic

Marian

Jun 13, 2010, 06:42 pm Last Edit: Jun 13, 2010, 06:51 pm by MarianLiliac Reason: 1
Greetings,

I just got a Wiznet 811MJ and on the papers or labels it came with there is no MAC address. Is there any way to get it from the device itself ?

cheers,
Marian

zoomkat

Look at previously developed code for the adapter to see if the mac address is assigned to the adapter in the code itself.
Google forum search: Use Google Advanced Search and use Http://forum.arduino.cc/index in the "site or domain:" box.

capt.tagon

#2
Jun 13, 2010, 08:19 pm Last Edit: Jun 13, 2010, 08:21 pm by Sean Reason: 1
If the MAC address is hardware assigned, set your device up with a manually assigned IP address, ping that address from another machine and then read the ARP table on the machine you pinged from. Windows at the console window, PING "IPADDRESS" then ARP -A

Looks like you manual assign a MAC address with the Wiznet, see this:

http://arduino.cc/en/Reference/EthernetBegin

Marian

Gentlemen,

thank you very much for your kind answers, but whatever I've tried my Linksys wrt54g with dd-wrt firmware will not recognize my Wiznet.
Is there any way of connecting this small gizmo directly to a computer just to see if indeed is working ?

Thank you,
Marian

westfw

Quote
I just got a Wiznet 811MJ and on the papers or labels it came with there is no MAC address. Is there any way to get it from the device itself ?

No; the device does not HAVE an inherent MAC address; YOU have to assign it one.  The concept that an ethernet interface comes with a built-in MAC address is supposed to be true at the "board" or system level, but the 811MJ is more of a chip-level device.

Quote
my Linksys wrt54g with dd-wrt firmware will not recognize my Wiznet.

What software are you using?  Like I said, the 811MJ is a chip-level module.  It won't do ANYTHING till you connected it up to some sort of real CPU and configure the chip with appropriate commands.

(I guess this is unlike certain other "network modules" (like the lantronix xport products) which really are tiny stand-alone network hosts.  At 2x the price.  You could look at the 107SR, which is a complete ethernet/serial gateway, and cheap.)

Marian

Westfw,

Thank you very much.
I did just the simple thing of connecting the module to my Arduino board and load the web server application from the Ethernet examples library.
I get that I can assign a MAC address (so did not change the one from example) and changed the ip to 192.168.1.123 to much my local network. No chance to see it as a client on the router table.

cheers,
Marian

Ran Talbott

Quote
No chance to see it as a client on the router table.

Which "router table"?  It sounds like you're looking for a DHCP client entry,  but you gave the Arduino a static address.

Have you tried just pinging it from another system on the LAN?

Ran

zoomkat

I have my arduino/ethernet shield connected to my netgear wireless router via cat5 cable. I just log into the router and view connected devices. MAC and IP are displayed for the ethernet shield.
Google forum search: Use Google Advanced Search and use Http://forum.arduino.cc/index in the "site or domain:" box.

Marian

zoomkat,

I've done absolutely the same thing, but is not coming under LAN connected devices.

Marian

Marian

Greetings,

done everything suggested without any hope. I knew something must be wrong. Upon carefully checking up of my homemade shield I realized that the ironical irony acted again. I had a minuscule (literally) bridge between MOSI and GND. Too bad for me !

Now it works !

No need for a pre-defined MAC address. It can take any generic one.
I have my reef tank controller (Arduino Mega) broadcasting its status using Wiznet 811MJ connected to a wrt54g in bridge mode. Pretty nice setup.

I noticed though on my tests that the Wiznet needs a hard reset after power resume. I will set up a digital pin to do this. BTW. Is there any hardware option available to this ?

Thanks a lot to everyone,
Marian

Mavromatis

So if you ship a product where is the best place to store the MAC address custom bootloader?  Program them via serial?  How do you get a list of MAC address for products?  I'd hate to "randomly" pick a mac that is used by another product(s).

Tuckie

If you were using the wrt, why not interface directly with the serial header, and just write a small bash script to handle serial communication on the wrt?

davekw7x

#12
Sep 03, 2010, 10:08 pm Last Edit: Sep 04, 2010, 12:18 am by davekw7x Reason: 1
@Mavromatis
Quote
How do you get a list of MAC address for products?
Companies that are going to manufacture an Ethernet product for distribution are assigned a block of MAC addresses from the IEEE Registration Authority: http://standards.ieee.org/regauth/oui/  There is a fee.

Quote
So if you ship a product where is the best place to store the MAC
It can be part of the program loaded into the product's non-volatile memory at the time of manufacture.  That means that every unit that is manufactured must have a different program compiled and loaded into it.  Probably not a very good idea for mass production.

Often the MAC address is in a small external EEPROM that is programmed separately before it is soldered onto the board.  The application program reads the EEPROM and initializes the Ethernet controller with that value.  For moderate production volumes, the EEPROM may be programmed in-circuit on some kind of test fixture at the end of the production line.  The EEPROM may have other information also (such as a unique serial number for each unit).

.
Quote
I'd hate to "randomly" pick a mac that is used by another product(s).


For your own use (or for any device used locally and not released into the wild):

If the second-least significant bit of the first byte of the six-byte MAC address is a '1', it's called "Locally Administered Address."  No commercial product should ever have that bit set to 1.

Note that the default MAC used in many Arduino example sketches has its first byte set equal to ASCII 'DE' (or maybe 'de'), so that bit is set, and that address should never be used by any commercial product.  (Thus, you sometimes see the six-byte array for the MAC address initialized to something like {0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0xED};)  Get it? "DEADBEEF..."  To the chagrin of some of my cowboy relatives, I have also used MAC addresses starting with "BADBEEF..." for personal use products.  (Smile when you say that, pardner...)

You only have to make sure that, no two MAC addresses are exactly the same on your own internal network where you are using these things.

Reference: http://en.wikipedia.org/wiki/MAC_address


Regards,

Dave

Mavromatis

So I bought a couple of the Microchip 24AA02E i2c Serial EEPROM with mac address (EUI-48 Node Identity) -- datasheet: http://ww1.microchip.com/downloads/en/DeviceDoc/22124D.pdf

I'm trying to figure out how to read this chip using i2c... anyone have any ideas?

Danny

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