Has anyone managed to get Ethernet working on custom PCB ?

I have just populated a DP83848CVV (Farnell # 128-6816) with a 50MHz Osc.

forced MAC address, using the program i published yesterday, which DOES allow me to change MAC Address.

but nothing happens at all :(

I have put LED = 1, as first line of code, but it stays off.

Please help.

Cheers

Ceri.

Someone MUST of got the Ethernet working,

I have gon through Schematics, and all appere to be the same as MBED,

I also get a 100nS pulse on one of the TX & one of the RX lines, of the RJ45 connector, same as MBED,

Although, Eth Osc En appears to be Hi allways,

Anyone ??

Cheers

Ceri

Hello Ceri,

I am very interested in Ethernet on custom board too. But it is far above my skills to get it done alone or make any progress from scratch. Now I am still getting familliar with all about USB.

Maybe can someone of mbed team give any point what can be wrong? Please keep updated here if You will make any progress.

Thank You very much, llu

Somewhat happy to read that i am not alone. I also have a phy problem, except that i know why it does not work. Might not be the same problem as you, but check that thread: http://mbed.org/forum/electronics/topic/3261/

I'm so interested in this discussion.. because I'm going to design my own pcb with mbed and eth...

Best of luck,

The board I got made, so far appears to work well, with one exception, the Ethernet.

although I did not take great ammount of care with tracking, I have made LPC1768 & Eth. quite compact, with the intention of making a very small PCB, if it all worked !

currently my PCB is 100*160, with lots of other 'goodies'

..

Giuseppe, are you intending to use the referrence design, or do you have annother schematic to follow ?

Cheers

Ceri

Ceri,

I intend to use the reference design plus some goodies. I think I will follow the cookBocck and the tutorial "mbed to hardware". The mbed group know this problem of eth in custom pcb? They can't help us?

Regards, Giuseppe

is there a link ?

I have been scouring posts for a while, it would be nice to read other developers news.

I have not come accross anything from MBED group !

Cheers

Ceri

I think I will use this:

http://mbed.org/users/ms523/notebook/turning-an-mbed-circuit-into-a-custom-pcb/

but my application will be based on ethernet so if ANYONE can make it work.. it will be a problem..

That design does not have Ethernet,

But the auther could of used 2 more pins from the FTDI chip, and it could of been directly programmable from FlashMagic program.

Still desperatly seeking Ethernet on custom PCB.

Ceri.

Just had a look at the LPCXpresso Ethernet PHY,

It uses a diferent PHY Chip, but the majority of the connections appear to be the same.

Except it has a crystal, not a clock chip.

I have looked at my PCB again today, compairing with reference designs, and the MBED its self,

the only difference between mine & MBED is the PHY chip is under the LPC1768.

Ceri

We are sure that mbed does not use a custom Ethernet PHY? Maybe the last letter of the part number. I do not have any ideas. Have you tried to compare with an oscilloscope pin to pin the mbed and your custom pcb? Who can help us?

Regards Giuseppe

I have looked at the PHY chip, layout, comparing MBED & My design,

As far as possible track lengths are concerned, the distance between LPC1768 & PHY chip, on my board is only 7 mm more. and my 50MHz clock is similarly placed.

I Goggled 83848JSQ, and a quick scan through, there does not appear to be anything different, except it states how wonderful the chip is !

And of course , it is lead-less (so I cannot put it down myself)

I would really like a solution to Ethernet.

Cheers

Ceri

Try this

http://www.ti.com/lit/an/snla105/snla105.pdf

I think they are not the same ( DP83848J DP83848C)

Thanks.

I have just had a quick look through, The only difference that I can see would be if you went from 'C' to 'J'

on the datasheet from Farnell, JTAG pins are reserved, leave floating (tick)

but just noticed ..

pins 20 & 21 should be pulled up with 2K2,

will try this afternoon.

RX_DV pull up or down - confused now.

Ceri

Attempted to pull 20, 21 & RX_DV up with (3) 2K2 resistors,

Still Not working

Ceri

Noooooh!

Let's think again

Giuseppe

Maybe that component don't work?

It is really difficutl, I know..

Giuseppe

What about changing or setting the MAC address? Do you use some external EEPROM with MAC? How you are going to implement this in the mbed APIs? This will be very helpful for all of us

Giuseppe

In this thread Simon gives the prototype of the function that you can implement to provide your own MAC address to the mbed Ethernet libraries.

Ok, so I implement that method on my main.c and the APIs will use that method to get the MAC?

I have implemented this in my code, I can set the MAC Address of one if my MBED's to another. and run websocket program.

as for the PHY chip, the data sheet so far as I can tell, is OK from MBED s device to leaded, but potentially a bit more tricky.

I have not seen anyone who has actually managed Ethernet on custom board.

or a source of the PHY chip used on MBED.

any one else help please.

Ceri

We planned on using other phy (from a switch) to implement our own board. Unfortunatly, due to lack of help and response from the core team, we were forced into rerouting the PCB, implementing the very same phy, which is connected to a free entry of the switch, as if it was plugged with a cable. Not only it is a bit lame -design wise- we had to completely change the routing and add a phy, which costs a bit. Too bad for such a nifty project.

However, it seems for the moment that when using the very same phy, it works fine. More when we receive the new PCBs.

Thank you vincent, please give us more info when you'll try the new PCB!

If you didn't know, the IEEE OUI plan (used for ethernet MAC addresses) has a self-managed address range. If the high order byte (octet) has a certain bit or two set, the MAC is defined as self managed. As long as that MAC is behind a NATing router, self-managed is OK.

thanks, there is also a lot of information in the Microchip data sheet for the Ethernet EPROM.

I am guessing, this is for the router option.

More info please,

can you update us on your PCB. And where did you get the PHY chip from

Ceri.

I used the DP83848IVV with the mbed libraries with success. I think DP83848IVV & DP83848CVV have the same pin out but are different with the mbed schematic DP83848J. The oscillator that I used is 50Mhz. I think the difference between the chips is that you need to pull up also Pin 7 (POWER_DOWN). This pin doesn't exist in DP83848J.

The pinout of the DP83848CVV is different from the pinout of the DP83848J that is shown in the mbed reference schematic.

You can find an example of how the lpc1768 should be connected to the DP83848CVV by checking the Keil evaluationboard http://www.keil.com/mcb1700/mcb1700-schematics.pdf

Thanks, finaly someone who got it working......

I will order some in the morning, just hope pinout is the same. Will keep you posted.

Thanks for the Keil link, i think that was the board i found as a good starting point.

Cheers

Ceri.

What you will buy Ceri? DP83848IVV or DP83848J?

Thank you for all the info

Giuseppe