RF Transmitter

RF Receiver












    • Standby: <1uA (less than 1 microampere)
    • only 3v power supply
    • 10...15m distance range
    • 2400 bps communication
    • 2 initial bytes for device recognition (ID bytes)
    • calculate the checksum of the sent data (to avoid fake commands)
    • few components
    • small size



    • Hardware UART at 2400bps
    • 4 bytes (32bit) length communication
    • checksum of the received bytes  (to avoid fake commands)
    • few components
    • small size




Transmitter description




Schematic of the transmitter


You can use the TLP-434A transmitter with RLP-434A receiver instead of TLP-418A and RLP-418A. The only difference is that  TLP-418A and RLP-418A work on 418MHz and TLP-418A and RLP-418A work on 433MHz . The microcontroller hex code works on both models (418A or 434A).

Remeber to use the same frequency modules. For example, use the TLP-418A transmitter with RLP-418A receiver OR use the TLP-434A transmitter with RLP-434A receiver.


Receiver description



Schematic of the receiver


The receiver is constituted by RF receiver module RLP-418A at 418MHz, the microcontroller AT90S2313 and the 2 relays which can handle any electric (or electronic) device up to 10 Amps (the contacts of my relays are 10Amp at 250Volts).


The RLP-418A is an RF receiver module that works at 418MHz with ASK modulation. There are 2 outputs from this module, the digital, with levels from 0v to VCC (5 volts in our case) and the analog output. Analog output is not used. The transmitter sends 4 bytes with 2400 bps 4 times and the receiver RLP-434A, collect them and move them to AT90S2313 through RxD pin, PD0.

Two reasons to select AT90S2313 (20pins) instead of AT90S2343 (8pins) is because

As antenna you can use a cable 30 - 35cm long



The power supply

Usage of transmitter


The RF modules TLP-418A and RLP-418A are manufactured by Laipac



  (c) 04.10.2004 by Serasidis Vasilis

Updated 24.07.2005