47Kohm resistor between pin15 and 16 of HT12D.Pin14 of HT12D to data pin of RF receiver module.GND pin 1-9 and Pin 14 of HT12E and Pin 8 of Atmega.Pin17 of HT12E to data pin of RF transmitter module.
If we couldn’t receive the transmitted data, there are possibilities that the transmitting and receiving frequencies are not matched. But it is a good practice to use both for lowering the noise coupling.Īlso, one thing is not mentioned in the datasheet, the variable inductor or POT at the middle of the module is used for frequency calibration. Those middle two pins are internally connected. The four pins are from Left to right, VCC, DATA, DATA and GND. In the above image we can see the pin-out of the receiver module. The receiving frequency is 433.92 MHz with a -105DB sensitivity. We can also add the antenna and solder it on the point denoted in the above image.įor the Receiver specification, the Receiver has a rating of 5V dc and 4MA Quiescent current as input. From the left to right the pins are VCC, DATA and GND. In the upper image we can see the pin-out of the Transmitter module. We can transfer data at a speed of 4KB/S with 10mW power. It does transmit in AM (Audio Modulation) protocol at 433 MHz frequency. If we see the specifications of the modules, the transmitter is rated for 3.5-12V operation as input voltage and the transmit distance is 20-200 meters.
It is the cheapest module available for 433 MHz These modules accepts serial data in one channel. Those are the transmitter and receiver modules we are using in the project. You can download these softwares from the given links:īefore going into the schematics and codes, let’s understand the working of RF module with Encoder-Decoder ICs.Ĥ33MHz RF Transmitter and Receiver Module
We use CodeVisionAVR software for writing our code and SinaProg software for uploading our code to Atmega8 using USBASP programmer.