Cerb40 Network card

Here’s a little project I am working on, primarily for prototyping use.

This is version 1. I have a few mistakes on the board with the gadgeteer sockets and one of the ethernet LEDs. Version 2 will fix those problems and add a i2c MAC address EEPROM as well.

If there is any interest I could make available through Creations or TKA.


Very cool module!

Very sweet indeed! What types of gadgeteer sockets did you expose? I’m down for at least one. Rough guess on cost?

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interested !

Count me in as well.

Now I just need to figure out what to do about the “my cerb40s already have short male headers” issue. I would like to avoid desoldering 40 pins on each. :think:

Also, do you have a part number for the female headers?

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I would recommend to not solder headers on network card. For people like @ ransomhall and me.

I will try to get a price in the next few days. I hope to send the new board rev out Monday to made.
No problem leaving the headers unsoldered. After a few modules its gets a little old soldering them anyway. :-[

Here is where I got the female headers. https://www.sparkfun.com/products/11376
They are not the easiest things to find. I couldn’t find them at Mouser or Digikey. If someone has another source for them let me know. It would be nice to get 20pos. Two 10 positions work but its a bit of a snug fit.

Currently this is how the sockets are wired. If there are any suggested changes let me know if the next day or two. (ENC28 connections RST# - PB10, CS# - PA13, INT# - PA14, WOL# - PB11)

Socket 1:
1 - 3.3Vdc
2 - See note*
3 - PC0/ADC123_IN10
4 - PC6/UART6_TX
5 - PC7/UART6_RX
6 - PC1/ADC123_IN11
10 - GND

Socket 2:
1 - 3.3Vdc
2 - See note*
3 - PA6/SP1_MISO/ADC12_IN6
4 - PA2/UART2_TX/ADC123_IN2
5 - PA3/UART2_RX/ADC123_IN3
10 - GND

*Note: Pin 2 from both sockets go to solder jumpers on the bottom that can be closed to connect to the USB power pin (+5Vdc). By default the jumper is open so pin 2 is not connected. (Each socket has its own jumper.)


Then I found this

And while it is a 40-pin option, might be possible to work with them to get 20-pin options made? Might have to order a few though :slight_smile:

@ Brett - Thanks for finding those headers. The Jameco are similar to what I am using now. I will have to get some of the 40pin and see how hard it is to cut them.

I didn’t get the board updates done this week. To many other distractions. (I did have 2 other prototype boards I wanted to get built. :-[ )

I hope to get the updates done and out for a run of boards next week.

Version 2 boards have been ordered. I pretty much re-routed the entire board. For some reason I had put the crystal opposite side of the ENC28 on version 1 so I had the crystal traces pretty long. :wall: I fixed my socket pins and added the I2C MAC EEPROM.

I will update here on success of Version 2, price and availability in the next week or so.


Ah yes, the old unreliable crystal too far away problem…

the problem I see with the cutting down of 40-pin headers is, unfortunately, you end up with a 20-pin piece and a 19-pin piece, as one is sacrificed at the break. But luckily… http://www.aliexpress.com/store/product/Free-Shipping-50-Pieces-lot-Stackable-Header-20-pin-2-54mm-for-Ar-duino-Shields-Gold/322082_1784332612.html

That’s a really great price. retail sites like adafruit and sparkfun gouge us on small items like this.

Looking forward to getting my hands on one of these boards.

like all small retail outlets, I can totally understand their pricing structures, but wouldn’t quite go as far as calling it gouging. Keeping a stockpile of little baggies of these must be a tremendous PITA. Don’t have to like it but don’t think I’m that concerned by paying a premium to be able to buy 6x of them individually. But when I want 10 or 100, I know it’s better to look elsewhere. I have a lot of 40-pin normal headers as I use them all over the place, and I just chop them down and sand the end smooth and they work a treat - bought cheap and I have probably enough to last me into my 60’s.

Thanks for finding those!

SparkFun and Adafruit can be a bit pricey but I can imagine the labour involved in packaging and inventory those small quantity.

Well maybe gouge is too strong a term… I’ve run into a few situations where their markup was an order of magnitude higher than what I would have considered reasonable. “reasonable” is tricky to quantify, as everybody will have a different idea of what that means. If it was my profit margin, I’m sure it would adjust upward :wink: