help on serial data transmission

[srimannarayanakarthik]

hi
I am making a project in which i am transmitting the data from serial port and going to receive it at a distance of 5 meters.i need to use wireless communications.i am explaining what i did till now.correct me if i go wrong anywhere.
i almost completed the design of the receiver.only thing left out is depending on the transmitter setting up the frequency.my receiver circuit has a band pass filter and an amplifier. then i am using a fir filter in MATLAB to get a rectified output and then synthesing the data.all the above filters and amplifiers i used are digital receivers and i am using MATLAB and DSP builder to build them. if i had gone wrong in any of the above please do correct me.
my problem started with the transmitter.i wrote a "c program" to transmit the data.i just need to send a 4 bit data. taking the suggestions from this forum i made it a 8 bit data so that i can neglect the first fout bits which might be altered during the RF data transmission.
i need a simple RF transmitter that can sense the data coming out from serial port and transmit it.i am searching it on Google but didnt get anything releavent to serial RF data transmission.i dont want to buy any kit.i want to make the transmitter myself.also i am a beginner in microcontrollers.
please do correct me if i am conceptualiy wrong anywhere in any of these things above mentioned and do tell me the problems i might face in transmission so that i can rectify them before in hand.
also i would be happy if any one help me out with a schematic for RF serial port data transmission

 

[JimB]

I just need to send a 4 bit data. taking the suggestions from this forum i made it a 8 bit data so that i can neglect the first fout bits which might be altered during the RF data transmission.

If the first four bits get "altered", what is to stop the next four bits being "altered"??

i need a simple RF transmitter that can sense the data coming out from serial port and transmit it.

A bad idea.
You would do far better to
1 turn the transmiiter on
2 send the data
3 turn the transmitter off.

If your serial port is RS232, there are already signals there which will do this for you, RTS and CTS.
If you set up the port to use hardware handshaking, the signal RTS can be used to turn on the transmitter.
When your program sends data to the port:
The port will set RTS, the transmitter will turn on.
The transmitter then sets CTS and the serial port will send the data.
The serial port then clears RTS and the transmitter turns off.

i am searching it on Google but didnt get anything releavent to serial RF data transmission.

If you expect to find something which works the way you have just described, I am not surprised.

i dont want to buy any kit.i want to make the transmitter myself.also i am a beginner in microcontrollers.

What experience do you have of radio?
What frequency are you going to use?
How are you going to modulate the RF carrier?

Buying ready made modules is probably easier, cheaper and more likely to work in this case.

JimB

 

[philba]

look up ASK. Also look up Manchester encoding. think about redundancy and error management.

 

[srimannarayanakarthik]

i have found a link(https://www.serasidis.gr/circuits/TRW-24G_transceivers/TRW-24G_transceivers.htm) i guess that might serve my puropse. but the trw24g,s mentioned are not avaliable in our country. can i use the prodcuts mentioned in this link**broken link removed**)
will thet serve my purpose?? can u suggest any other transmitters in that range