This pair of wireless modules operates in the 433mHz Frequency band, and the range can be up to 2 km. It is very simple to use, and can be a very cost effective solution for your long range wireless project. A slight latency of about 0.5 second may be expected. It's ideal for not-real-time-critical applications such as sending instructions to relays, cameras and other sensors and actuators. Please note that the pair only does one way communication. For applications where both way communication is needed, two pairs may be used.

Schematic:

Link to wiring Schematic

• Working volt : 5V
• Working current: ≤2.5mA(5.0VDC)
• Technology: Superhet （VCO, PLL）
• Modulation：OOK/ASK
• Working band:  433.92MHz 
  
• Bandwidth:  1.5MHz 
• Sensitivity:  -105dBm (50Ω) 
• Rate: ＜5Kbps
• Decoding form：PT2272
• Antenna length:  18cm
• Emission Distance: 2 KM

void setup() {
    pinMode(4, OUTPUT);
    pinMode(5, OUTPUT);
    pinMode(6, OUTPUT);
    pinMode(7, OUTPUT);
    Serial.begin(9600);
}
void loop() {
    unsigned char i = 0;
    for (i = 0; i < 16; i++) {
        send_data(i);
        Serial.print("i=");
        Serial.println(i, DEC);
        delay(500);
        send_data(0);
        delay(500);
    }
}
//====================================
void send_data(unsigned char data) {
    digitalWrite(4, (data & 0x01));
    digitalWrite(5, (data & 0x02));
    digitalWrite(6, (data & 0x04));
    digitalWrite(7, (data & 0x08));
}