abcd-ca
commented
5 years ago @berossm @ladyada
Here's my solution for having a unique mac address when using multiple devices with Ethernet Featherwing on the same network. Relies on the unique chip id on the ESP.
https://gist.github.com/abcd-ca/556e67d09e5619b2dd534c173b65624b
As currently implemented use requires either updating the source to have a hard coded mac address or some other external source. This becomes an issue when more than 1 or 2 are on the same development network.
The approach we have used for working with W5500 on products was the 24AA025E48T-I/OT. http://ww1.microchip.com/downloads/en/DeviceDoc/24AA02E48-24AA025E48-24AA02E64-24AA025E64-Data-Sheet-20002124H.pdf
This is an 400kHz I2C device. We selected this particular part because it the SOT23-6 has 2 address lines for some added flexibility in avoiding address conflict. This would end up using a Microchip OUI if using the stock part but the data sheet list Factory Programming. The Ethernet2 library could then be updated to make use of this new feature.
Routing could be very tricky give the location of the SCL/SDA lines with respect to the RJ45 connector. We don't do layout in house so that is a little outside of my comfort area.