I made a little PCB that connects an Arduino ProMini i.e. see here with a nRF24L module and contains two LEDs one Switch and a voltage divider to measure the battery voltage. The board can be ordered from here OSH PCBs for about $3 for 3 PCBs, in the US at least.
Send me a message if you want the Eagle PCB files.
See schematic below -- follow notes on schematic -- Do not power with 5V serial adapter, radio will not like 5V.
There is a slight silkscreen mistake on the pcb near SV2: Mosi should read Miso.
Pro mini used :