First CM prototypes!

A project log for PoE-FeatherWing

Like the Adafruit Ethernet FeatherWing, but with Power over Ethernet built-in!

Patrick Van OosterwijckPatrick Van Oosterwijck 05/10/2020 at 01:040 Comments

It's been quite a while since the last update.  First there was the Chinese new year, and then the Covid-19 situation caused major delays with pretty much everything.

In my case, the delay was mostly due to delays in the manufacturing of the flyback transformer and Ethernet jack by Link-PP.  I had decided I had enough confidence in the rev 2 layout to go to my contract manufacturer KingTop instead of doing another prototype round myself.  The plan was to immediately order 1000 pieces (to get bulk pricing) or most parts, but only 100 PCBs at first.  Then when everything seemed alright with the 100, have the 900 remaining units built.

I finally received word from KingTop that Link-PP had delivered the parts necessary to build the first round of 100.  They had received 1000 Ethernet jacks and 100 flyback transformers (since we hadn't tested their flybacks before).

Then I got some bad news: the Ethernet jacks had an extra pin and did not fit into the PCBs!

That was an unexpected horrible thing to happen!  Both the datasheet and the samples I had previously received from Link-PP had this pin missing.  Now we ordered 1000 pieces and they were all wrong.

Luckily, KingTop and Link-PP were both responsive and helpful to deal with the problem.  Link-PP confirmed that the pinout was correct and the extra pin was unused.  They just seem to have a variant of this jack with and without that pin.  Odd that they would have the same part number, that seems to be asking for trouble!

It was decided that for the build of 100 prototypes, KingTop would cut the pin, while they shipped the remaining 900 back to Link-PP for replacement.  With that settled, KingTop went to work quickly and built the units.

Looking good!  They shipped them and I received them late this week.  I added pins to a test unit:

Then I put it to the test by connecting it to a Feather M0 Adalogger board programmed with an Arduino sketch and hooking it up to a PoE switch:

It immediately worked!

I have now confirmed the PoE section works, the W5500 works, and I also checked that I could load a valid MAC from the 24AA02E48 chip.  Still to do: