If you only need to receive data at a certain frequency, then a simple RF receiver is perfect. Be sure to pair it with a transmitter of the same frequency.
SKU: WRL-10532| Brand: Sparkfun in AustraliaThese wireless receivers work with our 434MHz transmitters. They can easily fit into a breadboard and work well with microcontrollers to create a very simple wireless data link. Since these are only receivers, they will only work communicating data one-way, you would need two pairs (of different frequencies) to act as a transmitter/receiver pair. Learn More$7.54 AUD, inc GSTAUD, inc GST$7.54 AUD