434MHz/315Mz TX & RX

This RF module designed based on an RF Transmitter and an RF Receiver operates at a frequency of 434 MHz. An RF transmitter transmits serial data input wirelessly through its antenna connected at pin4. It transmits signals at the rate of 1Kbps – 10Kbps. The module consists of a SAW resonator tuned for 433.xx MHz operation. Moreover, there is a switching transistor and a few passive components to perform the functions.

This Radio Frequency (RF) module operates on Amplitude Shift Keying (ASK) with transmitter/receiver (Tx/Rx). The Transmitter transmits this serial input through RF. Then the Receiver module receives the transmitted signal placed away from the source of transmission. Thus these RF signals transmitted at a particular frequency and a baud rate.  The RF receiver receives the transmitted data only if it operating at the same frequency as that of the transmitter. Moreover, this RF module has a wide range of applications in a Car security system, Remote key-less entry, Garage door controller, Home security, Wireless mouse, Automation system.

The transmitter module consists of an RF tuned circuit and a couple of OP Amps to amplify the received carrier wave from the transmitter. This amplified signal is further fed to a PLL (Phase Lock Loop) which enables the decoder to “lock” onto a stream of digital bits which gives better-decoded output and noise immunity.

The transmitter is powered by Vcc at a range of DC voltage between 3.5V to 12V. Since the RF output is proportional to the supply voltage. Thus higher the voltage, the greater the range will be. Finally, the antenna pin meant for an external antenna. This RF module is often used with a pair of encoder/decoder. Thus the encoder encodes parallel data for transmission feed, while the decoder decodes the receiving signal. So HT12E-HT12D, HT640-HT648, etc. are some commonly used encoder/decoder pair ICs.

Pin Description

Transmitter Module:

• Ground (0V): GND
• Serial Data Input Pin: DATA
• Supply Voltage (5V): VCC
• Antenna Output Pin: ANT

Receiver Module:

• Ground (0V): GND
• Serial Data Output Pin: DATA
• Linear Output Pin: Not Connected NC
• Supply Voltage (5V): VCC
• Supply Voltage (5V): VCC
• Ground (0V): GND
• Ground (0V): GND