Problem with wireless serial transmisson

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There is no problem if you can implement the code. RF modules need a bit balanced data signal to be fed to them, like Manchester Coding.
 
Use the encoder and decoder I suggested with your micrcontollers.
Or study Manchester Coding with RF modules.
Ok You mean If not want to use Manchester coding the use encoder/decoder......
and if not want to use encoder/decode then use Manchester coding.....
Right ???

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Regards
Gaurav Sharma
 
Ok You mean If not want to use Manchester coding the use encoder/decoder......
and if not want to use encoder/decode then use Manchester coding.....
Right ???

--------------
Regards
Gaurav Sharma

Yes, if they are suitable for your application as those chips handle the coding for you.
 
Tell me one thing is Encoder/decoder have inbuilt line coding like menchester as they don't need any kind of coding to be implemented externally???

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Regards
Gaurav Sharma
 
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Tell me one thing is Encoder/decoder have inbuilt line coding like menchester as they don't need any kind of coding to be implemented externally???

Yes, the encoder/decode includes Manchester, or something that does the same job. Ignore the Holtek chips, they aren't what you want - but the module manufacturers make specific encoder chips that allow you to feed your normal serial from the 8051. They even sell modules with the chips built-in.
 
Yea, I already bought the encoder/decoder chips available at
**broken link removed**

From this I also bought ask modules as I said earlier.

So now I have to interface it with micro controller and block diagram becms

transmitter (AT89C51) pin 11 i.e TXD --->> Encoder---->>434MHz ASK

Transmitter Module--->>wireless medium--->434MHz ASK Receiver

Module--->>Decoder ---->>Receiver(AT89C51) pin 10 i.e RXD--->> L293D

Driver--->> control motors

right na??


----------------
Regards
Gaurav Sharma
 
Yes, or just write software routines for your 8051's to do the encoding/decoding.

But as I've repeatedly said, if you fit simple inverters it may well work well enough for you anyway.
 
we have to do special programing for encoding/decoding in 8051 or it is a function of encoder/decoder chip itself to encode n decode data??

Abt data inverting I am reading your tutorial.....lets hope get somethng good

In your tutorial you are talking about PC RS232 port or micro controller serial pin ???

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Regards
Gaurav Sharma
 
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Why aren't they? You can send 4 bit data to the HT12E, which is 16 different commands. All he is doing is controlling a few motors.

They are simple remote control chips, not for sending data - presumably he wants to send more than they provide, or why bother using a microcontroller?.
 
But actually I want to control Two DC motors and also want to control the speed of DC motor that I think can be done with the help of micro controller only.


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Regards
Gaurav Sharma
 
They are simple remote control chips, not for sending data - presumably he wants to send more than they provide, or why bother using a microcontroller?.

They send 4-bit data. They aren't designed for high data rates sure. Using a microcontoller, two nibbles can be combined to send a byte very easily. Much easier than writing a Manchester decoding and encoding program.
 
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we have to do special programing for encoding/decoding in 8051 or it is a function of encoder/decoder chip itself to encode n decode data??


-----------------
Regards
Gaurav Sharma
 
To Nigel Goodwin,

In your tutorial you are talking about PC RS232 port or micro controller serial pin ???


--------------
Regards
Gaurav Sharma
 
To Nigel Goodwin,

In your tutorial you are talking about PC RS232 port or micro controller serial pin ???

In the wireless tutorial, it's referring to the micro-controller pin, and just a general I/O pin, a hardware UART is pretty useless for this application.
 
They send 4-bit data. They aren't designed for high data rates sure. Using a microcontoller, two nibbles can be combined to send a byte very easily. Much easier than writing a Manchester decoding and encoding program.

But you're adding extra hardware, slowing things down, and drastically reducing functionality. Manchester routines with a suitable packet size are so much more versatile, and require no extra hardware.
 
I have read your tutorial they are explaining Manchester code...

But now question arises how to implement that...??

Also please respond to post #35..........


--------------
Regards
Gaurav Sharma
 
we have to do special programing for encoding/decoding in 8051 or it is a function of encoder/decoder chip itself to encode n decode data??

I thought it was pretty obvious?, an encoder/decoder chip does the encoding/decoding - the clue is in the name.

Try this page for an example, and links to datasheets:
 
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