VoCore Forum

Hi,

I wanted to test ethernet on my vocore without the dock.
I cut a ethernet cable and connected it to the vocore.

This is how i connected it.
wire 1 (White/orange) -- p4TP
wire 2 (Orange) -- p4TN
Wire3 (white/green) -- p4RP
wire6 (green) -- P4RN



Is that no enough or do i need to enable it somewhere else?

You need Ethernet magnetics and a 1.8v pin on the centertap.

Look on RS/Digikey/Mouser/Farnell etc for an RJ45 with integrated magnetics. There will be 3 pins for Rx and TX. Each centertap pin goes to 1.8v then it all works. Without that you get nowhere.

What kind of minimum circuitry would I need for a PCB to PCB ethernet cable? (ca. 5cm in length)
I tried to wire it directly but no link is detected.

Do you definitely need Ethernet? It would be very easy to make a serial connection at that distance.

As I said, if you want Ethernet then you need the magnetics with 1.8v on the center tap.

You can buy "magjack" RJ45 ports with the magnetics built in which is what I have used on all of my VoCore boards.

Did anybody successfully connected to ethernet without magneticks/rj45 jack yet?
(which should be possible - see TI application note www.ti.com/lit/an/snla088a/snla088a.pdf )

Peter - this app note is only applicable for TI products - you really should think about using magnetics - at least for ground compensation current which could damage your circuit.

I've wondered about doing this for years with various little Ethernet boards; This would be great for daisy chaining or cluster computing back plane, small robots, etc. Did you ever make this work?

I've also been having this same problem.
I didn't realize that more components were required.