Designing Raspberry Pi Compute Module with Ethernet capability

Question

I recently got the new Raspberry Pi Compute Module due to the small size and ability to create custom board attaching with it.

The application requirement I need is just USB, some I/Os and LAN.

I realised the module development kit doesn't not come with Ethernet capability. I need LAN to create a client/server secure connection through the Pi.

Anyone can share info resources on how to make this compute module ethernet capable? any schematics?

Answer 1

The Broadcom BCM2835 does not have on-board ethernet so just like the standard raspberry pi you will need to add ethernet via USB. On the B/B+ the ethernet was provided via the LAN9512 USB hub/ethernet chip.

So for the compute module development board you can just get a compatible USB ethernet adapter.

For a device built around the compute module you might want to look at something like the LAN9512 or LAN9514.

You could look at the schematics published by the Raspberry Pi Foundation to see how they did it.

Answer 2

You can also use the ENC28J60 Module, which is only a few dollars from the usual places - ebay, aliexpress etc, and won't consume your USB port.

To do this, wire things up:

Pi            ENC28J60
----------------------
+3V3          VCC
GND           GND
GPIO8         CS
GPIO9/MISO    SO
GPIO10/MOSI   SI
GPIO11/SCLK   SCK
GPIO25        NT

Now, with your pi booted, open up '/boot/config.txt':

sudo vi /boot/config.txt

Towards the end of the file, add:

dtoverlay=enc28j60

Now reboot your pi, and bask in the pleasures of network.

This is described in more detail on the RaspberryPi website.

Answer 3

Compute module 4 has an on-board ethenet PHY simplfing matters so you only need to add a magjack (or separate transformers and jack) to your carrier board.