Hi! My first post
I have developed a small card that fit my needs (and probably more).
It has space for 3.3V regulator for the NRF card (and other 3.3 components) and most of the available pins in one place.
The sensors inputs are designed with RC servos in mind. The power is in the middle so it does not make smoke when you connect your 3pin dupont cable the wrong way.
Power input is designed so that you can choose with a simple jumper if you want to use the internal regulator within the Pro Mini card or have regulated power from the outside directly to Vcc.
In the bottom of the card I have two unconnected power rails that can be connected from "PWR JMP" to get VCC, 3.3V regulated or raw input for sensors that require different power levels.
The only problem with the current sent of cards I have is that the NRF card is so close to the Pro Mini card that I had to tilt the socket a little bit to make it fit and that the silkscreen for the Arduino is wrong.
For v1.1 I will probably also add som indicators what pins that are available as well so that I don't have to guess or check the schema every time
It's designed to fit into a box from biltema (http://www.biltema.se/sv/Bygg/El/Fast-installation/Kulodosa-35469/).
The battery holder is hot glued to the top of the box.