RF module receiver and 3 buttons transmitter

[muganga]

hi everybody...

I would like help from you

if I buy RF (transmitter and receiver) modules below

Transmissor + Receptor RF 433 MHz (Controle Remoto Completo) - R$ 25.00 em MercadoLivre



in this case should I use a microcontroller to recognize wich button is pressed?
How to know what protocol that transmitter is using for each button when pressed?


thank you in advanced

muganga

 

[welove8051]

u dont specifically require micro controller. check this two ic's namely ht12e(encoder for tx) and ht12d(decoder for rx) 4 bit or ht640/648 8bit.

 

[muganga]

tks welove8051...

I have seem those encoder and decoder...but if I want use those modules showed at link I posted before.

How receiver recognize which button was pressed?

thank again

muganga

 

[welove8051]

for encoder ht12e(tX) pin 10 to 13 are input. refer page 12 of datasheet. similarly for decoder ht12d 10-13 are output. refer page 8

 

[pranam77]

How receiver recognize which button was pressed? muganga

When a button is pressed on the transmitter side, the encoder chip emits corresponding codes which is then modulated with the RF of the Tx. The receiver receives that signal, and decodes that particular code which is transmitted by the transmitter, and thus acticates the corresponsing relay. Address codes are too sent by the TX which are set by the address pins of the encoder chip which need to match with those set by the decoder chip.

 

[muganga]

when I power on decoder ht12d pin D8 has 3,68 Vdc and according manual should have low.

So my remote control is working reverse. When I press button at encoder ht12e led turn off instead of turn on.

could you give me a help.?

many thanks

muganga

 

[welove8051]

check this circuit


in tx diagram . the common point of switch is t be connected to ground

 

[pranam77]

when I power on decoder ht12d pin D8 has 3,68 Vdc and according manual should have low. So my remote control is working reverse. When I press button at encoder ht12e led turn off instead of turn on. could you give me a help.? many thanks muganga

Please note that when the Decoder chip verifies a signal and gives an oputput, (may be the D8 pin) the pin will be having a LOW logic, and this applies to all the output pins. Thus if you are checking the outputs with a LED, the posetive pin of the LED may be connected to 5Volts (Presummed that the Chip is supplied with 5 volts and the LED will have a series resistance of 330E) and the negetive pin to the output pin of the decoder. If a relay is connected the two transistor arrangement as shown above may be used.

 

[muganga]

pranam77

now the led is turning on when button is pressed at transmitter...only thing is missing is led keeps on "forever" until another button been pressed.
How can I do this. Outputs at decoders supose to have latch?

tks

muganga