Doug has designed a PCB that makes node-building easy with an Arduino Pro Mini 3.3v and a RFM95W radio. As of today, the project isn't complete but last night we cut the first prototype on Fab Lab's Other Mill and you can see the result here.
Mariano and Doug have independently been pursuing this so that we all have an easier time of building nodes for use cases. We'll update you when it's done but they're making good progress. More news shortly ... they're cutting another iteration tonight.