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Topic: Connecting an Ethernet PHY to Arduino Due (Read 45 times) previous topic - next topic

Palliser

Jan 15, 2013, 07:14 pm Last Edit: Aug 03, 2013, 04:35 am by Palliser Reason: 1
I thought that it would be a good idea to open this post regarding the connection of an Ethernet PHY to Arduino Due, given that I still revising a couple of approaches I have on hand. The first one belongs to Atmel (doc11153). The second one is my own idea. Let's start talking about the first one which looks realizable and later on, my own approach.

As most of you may know, the core inside Arduino Due (SAM3X8E) integrates an EMAC module to implement a 10/100 MAC compatible with the IEEE 802.3 standard. The approach of Atmel evolves around to the idea of connect an external Physical layer transceiver (or Ethernet PHY) by Media Independent Interface (MII) or Reduced Media Independent Interface (RMII). Then, they made a comparison between both considering frequency, cost and manufacturers. Finally, they present the implementation using a 10/100 Mbps fast ethernet physical layer TX/FX single chip transceiver (DM9161) set in RMII mode with a 50MHZ crystal connected to the development kit SAM3X-EK using a HTTP demo under BeRTOS.

I have planned, as I did with the CAN bus approach, to run the demo to familiarize with their approach.

OK. Now my approach: I'd been thinking to wire directly the Ethernet MAC embedded inside Arduino Due with an off-chip Ethernet PHY (built-in can apply also) and add the correspondent coupler and an Ethernet connector. Then, as I did with the CAN, I will start to port part of the SAM3X-EK 32-b  Ethernet libraries to Arduino Due. I haven't made up my mind yet for the phy but it could be like DP83848C.

As you may have noticed, my approach is not original. I did read similar approaches in this forum but I have no heard of anyone working on one yet (ArgusTech? Markus_L811?). So here we go. Any comments and more ideas are very welcome.


April 03, 2013, 10:49:00 PM - I just removed the attachment with a non-working EMAC library (I will publish in github the new working EMAC library very soon).

Palliser

#1
Jan 15, 2013, 10:03 pm Last Edit: Jan 15, 2013, 10:07 pm by Palliser Reason: 1
By the way, for those who are asking to themselves how in the world the 8 Ethernet FPGA pins can be reached/connected, the answer is: a customized micro 16-pin clamp that I am designing.  8)

ODwyerPW

I like the idea of 'native' Arduinoe Due Ethernet. How will you be installing the RJ45 header? Shield? Some sort of Side Car?
Quiero una vida simple en Mexico...nada mas.

Palliser

Hello ODwyerPW. It will be a side car shield board as follows:

Pins 113,114,115,118,119,120,121 of SAM3X8E of Arduino Due connected via a wedge clip wired to a PHY like DM9161AEP soldered to an Arduino proto-shield board. The board will contain the crystal and necessary circuitry (caps, resistors). The PHY will be wired to a coupler and a RJ45 connector, both also soldered to the shield.

The optimal approach should be a pure shield but the problem lies in the fact that there is not direct access to the Ethernet pins in the SAM3X8E.

My goal here is to develop in a real and practical way an Ethernet interface exploiting the MAC. I believe that in future generations of Due, an embedded PHY should be considered.
 

Palliser

I think that for reasons of space, the embedded PHY has no place, thus, at least a mini Ethernet terminal should be re-considered (remember the eagles).

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