serial rf module interface with 8051

[gdinu0]

hi
I have a problem interfacing RF module(433Mhz ask) to 8051(atmel 89C51).
I am using two micro controllers

First: I have written a simple program to transmit 'A' serially if P1^0 is high in transmitter micro controller(uc1). and at receiver micro controller(uc2) to take serial data and put in on P1 of (uc2). Baud rate 4800
I have connected TX of transmitter to Rx of receiver micro controller(uc2) directly for testing.
I have used different power supplies for each microcontroller.

problem1:I am not receiving data on uc2

If I use a common ground then I am receiving the data i.e P1(0x41=='A'). how can i get the data without using common ground??

I have interfaced RF module with common ground

Problem2: I am not getting the output

I have checked the rf module with help of digital CRO.
Then I got to know that transmitter and receiver are working correctly and i am receiving 'A' at the receiver 01000001(0x41). But the problem is that as soon as I connect receiver output to Rx pin the receiver gets blank(I checked with CRO it reads no signal).this is my problem please help me this is a part of my final project if any one knows anything please reply me back.

 

[demetal]

Hi,

Try to decrease the baud-rate to least value or use Manchester coding.... check for some old threads here....

 

[IanP]

hi
I have a problem interfacing RF module(433Mhz ask) to 8051(atmel 89C51).
I am using two micro controllers

First: I have written a simple program to transmit 'A' serially if P1^0 is high in transmitter micro controller(uc1). and at receiver micro controller(uc2) to take serial data and put in on P1 of (uc2). Baud rate 4800
I have connected TX of transmitter to Rx of receiver micro controller(uc2) directly for testing.
I have used different power supplies for each microcontroller.

problem1:I am not receiving data on uc2

If I use a common ground then I am receiving the data i.e P1(0x41=='A'). how can i get the data without using common ground??

Common ground is a reference for both microcontorollers, without it it's like without a bridge ...

I have interfaced RF module with common ground

Problem2: I am not getting the output

I have checked the rf module with help of digital CRO.
Then I got to know that transmitter and receiver are working correctly and i am receiving 'A' at the receiver 01000001(0x41). But the problem is that as soon as I connect receiver output to Rx pin the receiver gets blank(I checked with CRO it reads no signal).this is my problem please help me this is a part of my final project if any one knows anything please reply me back.

Is the ground of the RF receiver connected to the ground of the receiving microcontroller (common ground)?
You should have 2-wire connection between them....

 

[gdinu0]

Common ground is a reference for both microcontorollers, without it it's like without a bridge ...

Is the ground of the RF receiver connected to the ground of the receiving microcontroller (common ground)?
You should have 2-wire connection between them....

yes RF receiver is connected to the ground of receiving microcontroller(common ground).

---------- Post added at 20:20 ---------- Previous post was at 20:15 ----------

even i decreased the baud rates but no use. should i use any kind of buffers etc can you people please suggest me if any.

will encoder/decoder can solve my problem??

 

[demetal]

Hi,

Check the type of data pin from RF module connected to the receiver microcontroller... Rf module receiver consist of two types of DATA pins... One for LINEAR OUTPUT and other one for DIGITAL OUTPUT.... Use the digital output pin to connect to receiver controller.... refer datasheet to get the pin number.....