I was trying to find a basic shield for an Arduino Pro Mini 3,3V to use/connect to an RFM95/96, which btw. seems to use the same footprint as the RFM69CW / RFM69HCW modules, but did not find anything right away. Intended use is for local networking with MySensors as well as getting into TheThingsNetwork.
As I did not stumble upon something readily available, I tried to hack something together in KiCAD. I do not have any clue about all of this. I am just posting this here to invite others to take a look and perhaps give me a hint about what needs to be improved.
v0.2 added, incorporating BME280 (4-Pin THT formfactor) footprint. Still untested, but I will go forward with this for now and order it soon. Still having to make up my mind where to place VIN/GND connectors for powering it, and will probably add a MCP1700 LDO as I will run this from a (protected) LiPo.
v0.3 Incorporated Power Supply pins and MCP1700-33. I use Arduino Pro Minis with desoldered Power LED and regulator and will power via this MCP1700 instead, probably from a 14500 LiIon battery.
Uploaded latest version with additional footprint for a capacitor for reliable voltage measurement (untested; inspiration: https://jeelabs.org/2013/05/16/measuring-the-battery-without-draining-it/ ). The board from the previous version works well so far for a couple of weeks now with approx. 14microamps sleep current (removed power LED and regulator from Arduino Pro Mini; BME280 unmodified, there seems to sit another regulator which could be removed), running on a 14500 (AA size) LiIon.