RF module coonections- with MCU and PC

[niru005]

MCU: pic16f877a

problem:
a LCD display is connected with a MCU. i need to On and Off that using the ST-RX04-ASK module Tx and Rx from PERSONAL COMPUTER. - letter "N" for On, letter "K" for Off- has to be pressed from keyboard.

i think there are 2 kind of solution to connecting that RF module. i don't know the correct way.

1)transmitter pin of the RF module is connected 'straightly' with PC's serial pin's transmitter (Tx) pin.
for the recive signal,
Rx pin of the reciever, is strightly connect with Rx pin of MCU (like serial communication - uart).
PC --> Tx(RF module)
Rx(Rf module) --> Rx(MCU)
for this purpose do i need to use RS232 protocol?

2) using a encoder and decoder
PC --> MCU-1 --> HT12E --> Tx (RF module)
Rx(RF module) --> HT12D --> MCU2


CAN YOU PLEASE TELL ME WHICH IS CORRECT WAY?

Thank you..!!

 

[ctownsend]

2) using a encoder and decoder
PC --> MCU-1 --> HT12E --> Tx (RF module)
Rx(RF module) --> HT12D --> MCU2

since these encoder/decoders are 4 bit, you will probably want to send a 4 bit value (0x00 - 0x0F) rather than a letter.

 

[niru005]

the letter's ascii value can be checked in the MCU-1 and set 1 of the 4pins in MCU. then from the decoder we can check which pin is set, according to that we can on the LCD.