The RFM12B Board is a compact breakout board for HopeRF's RFM12B radio module, as featured on all JeeNodes and JeeLinks. If you are looking for an affordable way to add wireless communication to your Arduino (compatible) board, this is the board to get.
The board works with a whole range of Arduino (compatible) boards, such as official Arduino boards (both 5V and 3.3V versions), Freeduino, JeeNode SMD kit, RBBB and Boarduino. For ease of use, the header pins are labeled with signal names as well as Arduino pin numbers. Just plug it into your breadboard and connect it as indicated.
The RFM12B radio module supports a power supply level of up to 3.8V. For using the RFM12B in a 5V setting, this board features a step-down voltage regulator circuit and the required voltage level converters for signal pins used. When the supply is 3.3V, the regulator and level conversion components can be left out. Mount the RFM12B module on the pads provided (moderate soldering skills required).
An antenna must be connected to the module - for 868 MHz, a 82-mm long piece of wire works well (quarter wavelength).
The Kit variant includes the parts needed for power and level conversion, the RFM12B radio module (868 MHz), and an 8-pin header. Solder everything on to make your Arduino (compatible) board wireless.
The PCB-only version contains just the board. No parts, no headers, no RF module. If you are using the RFM12B Board in a 3.3V setting, and want flexibility for frequency band choice, use this version - just add the C2/C3 decoupling capacitors and an RFM12B 868 MHz module or 433 MHz module radio.
For bulk requirements, try the 6Pack or Bonus Packs - that's 11 Kits or PCB's for the price of 10.
The documentation and full design details are freely available, as well as an Arduino library with sample C code.