Earlier in the year I lashed together an ESP8266 ESP-13 and an RFM69HW to serve as a gateway. It works great (see photo). Two things to notice: the compact footprint and the bi-pole antenna. The bi-pole antenna yields an absolutely huge improvement (>12dB) in antenna performance over using just a typical wire mono-pole antenna coupled to a typically undersized ground plane. Actually, the photo with the quarter (for scale) shows the footprint of a different, mono-pole version that I did prior to it, but the footprint is similar. The bi-polar version had a slightly bigger footprint so that the ground antenna could stretch out to overhang the edge (off to the side) of the ESP-13 module. If there's sufficient interest (?), I could make an RFM69 shield for the Wemos D1 Mini that should accomplish much the same thing as either the mono-pole or bi-pole versions. Alternatively, I could design a PCB that simply does it all. Meanwhile, I wanted to make more people aware of the advantages of using a bi-pole antenna for the RFM69, especially for a gateway.