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Cerb40 Network card


#1

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.


#2

Very cool module!


#3

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


#4

interested !


#5

Count me in as well.


#6

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?


#7

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


#8

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
7 - PB5/CAN2_RX/PWM/SPI1_MOSI
8 - PB3/J_TDO/PWM/SPI1_SCK
9 - PB4/J_TRST/PWM/SPI1_MISO
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
6 - PA1/UART2_RTS/ADC123_IN1/UART4_RX
7 - PA0/UART2_CTS/ADC123_IN0/UART4_TX
8 - PB7/I2C1_SDA/UART1_RX
9 - PB6/I2C1_SCL/UART1_TX
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.)


#9

http://www.jameco.com/1/1/58068-rs1-20-g-561-a11596-1x20-position-pass-through-style-header-arduino-shields.html

Then I found this
http://www.aliexpress.com/item/Free-Shipping-20-Pieces-lot-Stackable-Header-40-pin-2-54mm-for-Ar-duino-Shields-Gold/1784285137.html
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:


#10

@ 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.


#11

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.


#12

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


#13

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.


#14

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.


#15

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.


#16

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: