Use these two compatible RF receiver and transmitter modules to send AM Radio Waves directly between two Ardruinos.

This package includes both the RF receiver and the transmitter modules.

Transmitter : 

Working voltage: 3V - 12V  fo max. power use 12V
Working current: max  Less than 40mA max , and min 9mA
Resonance mode: (SAW)
Modulation mode: ASK
Working frequency: Eve 315MHz  Or  433MHz 
Transmission power: 25mW (315MHz at 12V)
Frequency error: +150kHz (max)
Velocity :  less than 10Kbps

So this module will transmit up to 90m in open area .

Receiver :

Working voltage: 5.0VDC +0.5V
Working current:≤5.5mA max
Working method: OOK/ASK
Working frequency: 315MHz-433.92MHz
Bandwidth: 2MHz
Sensitivity: excel –100dBm (50Ω)
Transmitting velocity: <9.6Kbps (at 315MHz and -95dBm)

The use of an optional antenna will increase the effectiveness of your wireless communication. A simple wire will do the trick.

the connection for this module is very easy .

for Transmitter :

Vcc ->5V
ATAD ->D12" (This pin number can be changed in code)
Gnd >>> Gnd

Receiver :

Vcc -> 5V
Data -> D12
Gnd -> Gnd

There is a popular Library for arduino Called "" VirtualWire"" Created by Mike McCauley that does all the hard work for you, available HERE

An instructable guide is available HERE

Remember to add an external antenna for maximum range!
Can be used with or without an Arduino!