RCM5700 Adding RJ45 Jack

Rabbit
21

Chuck,

on a new pcb of my board I place only the miniPCI connector. Before I replace from the miniPCI connector the 4 pins relative to Rx+, Rx-, Tx+ and TX-: in this way my pcb has no connection on the Ethnernet interface of the Rabbit (excepted the LED of the ethernet onnector).

I took a module RCM5700, place the RJ45 connector on.

If I connect the module with the connector on the development board it works, on my board no. The only rule of my board, at this point, is power the module up. I check the power supply on the tantalum capacitor of the module: all right: 3.3V and 1.8V (probably the core voltage).

So, I cut the Rx+, RX-, TX+ and TX- nets of the development board in order to disconnect the Ethnernet connector of the dev. board; I remove the filter (L, 2R and C).
The module placed on the modified development board works well.

Between the two part of the miniPCI connector on the dev. board there is only copper, on my board I have some components… should it be a problem? I don’t think so.

Thank you very much for your effort!

22

Nicola,

I would say you’ve done everything right…!

Only one more idea…

With your modified RCM5700 module off the test board, take power from the Rabbit test board with two wires to your module.

With your module sitting on the table test it this way…

I’m concerned about power supply ground loop’s and the ethernet signals…

if your board works plugged into the test board using the test board power,
it should work, OFF the board and just wired power to the RCM5700…

IF it does NOT work…then we need to look at the MiniPci interface signals
again…

be sure to power up all pins (1,51 - ground) (2,52 - 3.3V)

Make sure Pin 28 is not pulled LOW…( RESET LINE )
Let me know…

23

Nicola…

I was looking at your PCB again…

Can you send the Schem to me and let me review it ??

Chuck

Charles.Terra@ge.com

24

Hi, Nicola, Chuck.

I have a problem very similar to Nicola. In my board, ethernet doesn’t work but in demo board works fine. I have followed all suggestions, but I haven’t fix it.

Nicola, did you fix your problem? What was the solution?

Regards,

Luisma

25

Hi Luisma,

I fixed the problem on my system.Pay attention to the LED signals.They are not only for the activity and ethernet presence indication but during the start up they set the ethernet controller placed on the RCM5700.

So, try to connect these two pins like the drawing and then let me know.

Nicola

26

Thanks a lot, Nicola.

I have fixed my board. The problem was led connections. :smiley:

Regards,

Luisma

27

Fine to hear your good news!

I spent about a week on the problem, and I destried my development kit during the test :/.

Good luck for your job!