how to use two 433MHz Rf modules in same place using encoder decoder !

[kunaltg]

Hello guys !! I want to use two 433MHz rf transmitters at same place !!
I have implemented 2 RF transmitter & receiver circuits using :-
-Easily available 433MHz modules from ebay.in
-Ht12d & Ht12e ICs for decoding & encoding data !!
These encoder & decodera have facility to àdjust address also !!

So i have configured different addresses to my 2 transmitter & receiver Pairs !!


But even after setting different addresses these two RF systema doesn't work!!! (Both Work flawlessly with other transmitter turned off i.e. only one transmmitter ata time !!)


Please help me to solve this issue!! Z

 

[jayanth.devarayanadurga]

Post circuit ans code. Don't expect help without doing it. Have you put antennas to all the 4 RF modules. If not put 18 cm wire as antenna.

 

[keith1200rs]

With two transmitters on the same frequency transmitting simultaneously they will interfere with one another. Imagine two radio stations transmitting on the same frequency. You need to use different frequencies or only transmit in short bursts at random intervals, not continually.

Keith

 

[kunaltg]

Thanx keith , this means the only way is to use another frequency module ! Because in my application both transmitters should be able to work simultaneouly !!

- - - Updated - - -

@ Jayanth , yes bro all rf modules are connected with 17cm antenna !!
And both systems works absolutely fine when another is turned off !! So my circuit is not wrong , its a problem with module only !

 

[keith1200rs]

How much data are you transmitting? It is quite possible for multiple transmitters to share one frequency but they must transmit in bursts.

Keith

 

[kunaltg]

^ ohhk Got it bro !! i am not transmitting a lot data ,,I am using HT12E encoder ic which has 4 inputs ! I am using only 2 of these !! Its just a Wireless switch ,,& not like wireless data Acquisition system !!

 

[bigdogguru]

Are you using these 433MHz ASK RF TX/RX pairs with a microcontroller?

If so have you considered replacing the ASK RF TX/RX pairs with an inexpensive transceiver with built-in encoding/decoding, like the Nordic nRF24L01+?

You can purchase a pair of nRF24L01+ transceiver modules on eBay for less $2.50 shipping included.

eBay Search for pair of nRF24L01+ modules

Nordic Semiconductor nRF24L01+ Product Page

The Nordic nRF24L01+ is a highly integrated, ultra low power (ULP) 2Mbps RF transceiver IC for the 2.4GHz ISM (Industrial, Scientific and Medical) band. With peak RX/TX currents lower than 14mA, a sub μA power down mode, advanced power management, and a 1.9 to 3.6V supply range, the nRF24L01+ provides a true ULP solution enabling months to years of battery life from coin cell or AA/AAA batteries. The Enhanced ShockBurst™ hardware protocol accelerator offloads time critical protocol functions from the application microcontroller enabling the implementation of advanced and robust wireless connectivity with low cost 3rd-party microcontrollers.

The Nordic nRF24L01+ integrates a complete 2.4GHz RF transceiver, RF synthesizer, and baseband logic including the Enhanced ShockBurst™ hardware protocol accelerator supporting a high-speed SPI interface for the application controller. No external loop filter, resonators, or VCO varactor diodes are required, only a low cost ±60ppm crystal, matching circuitry, and antenna.

Features:

Low cost, single-chip 2.4GHz GFSK RF transceiver IC

Worldwide license-free 2.4GHz ISM band operation

250kbps, 1Mbps and 2Mbps on-air data-rate options

Enhanced ShockBurst™ hardware protocol accelerator

Ultra low power consumption – months to years of battery lifetime

Drop-in compatible with the Nordic nRF24L01 previous generation Nordic RF transceiver IC

Fully on-air compatible with all Nordic nRF24L Series, as well as nRF24E and nRF240 Series

nRF24L01+ Datasheet

They are fairly popular and straight forward to utilize in an application, as such there are C source libraries available for many microcontrollers.

BigDog

 

[kunaltg]

^ for using this,,i think i need to use controller on both sides !! transmitter as well as receiver !!

 

[bigdogguru]

Are you using these 433MHz ASK RF TX/RX pairs with a microcontroller?

If so have you considered replacing the ASK RF TX/RX pairs with an inexpensive transceiver with built-in encoding/decoding, like the Nordic nRF24L01+?

Yes, which is why I asked whether or not you were using a microcontroller with the ASK RF TX/RX pairs.

BigDog

 

[kunaltg]

^ No i am using uC on receiver side only !! On transmitter side there is no uC !!