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Wireless Tx-Rx pair suitable for uC.

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mananshah93

New Member
Hi to all!
I am trying to make wireless communication betweem two microcontroller, I am looking for suitable tx-rx pair with appropriate encoder-decoder...
I have used 433MHz-Tx-Rx pair with HT12E and HT12D encoder-decoder, but I was able to send only 4 bits at a time...

RF Modules (Tx + Rx Pair) 433 Mhz ASK [RKI-1064] - $12.19 : Robokits World, Easy to Use, Versatile Robotics Kits...

Can anyone suggest me best Tx-Rx pair with suitable encoder-decoder that can be connected to microcontroller....

Thanks.
 

3v0

Coop Build Coordinator
Forum Supporter
You can use the radios you mentioned for communication between micro controllers without encoders if you use Manchester encoding. Nigel has a PIC ASM tutorial on how to implement it. There has also been a recent thread here on doing it in c.

You send a serial stream of bits and use the micro controller to do the encoding and decoding. You can in effect have as many channels as you want.

If you want to stick with the encoder/decoder chips
The same place you listed has
HT640 and HT648L 8 channel Encoder Decoder IC's for RF Modules

The way it works is that you set 18 bits on the encoder and the same 18 bits show up on the decoder. If the first 3 bits are uses to indicate channel you are left with 15 bits of data. If you can live with fewer data bits you can get more channels.

The problem is that this would tie up 18 micro controller pins on both micro controllers.

I hope that gives you same idea of what you are looking at.
 
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mananshah93

New Member
one more thing, if I have less devices then rest of address pins not needed to connect with uC, it can be left open...
for example if I use 2 address lines for 4 devices then rest of the address lines can be open...not needed to connect to uC..
But you are telling if I use 3 address lines then I can use 15 data lines...I don't understan how? In HT640 and HT648L pair maximum 8 data bits can be used irrespect to how many address lines you use..
If it is possible then please tell me how??
 

mananshah93

New Member
Using 640 and 648L encoder-decoder, i am able to send 8 bits at time, I want to transfer 10bits at a time...is there any encoder-decoder which can transfer 10 bits of data at time?
 

Nigel Goodwin

Super Moderator
Most Helpful Member
As with most systems, you simply send it as two (or more) 8 bit bytes - however 3v) seemed to think it was already 15 bits.

Manchester coding though is a packet system, so lends itself to multiple byte packets.

EDIT:

I've just checked the datasheet (the device is long discontinued anyway), and it's 8 databits only, so you'd have to send ten bits in multiple bytes.

The obvious solution is not to try and use ancient crude remote control IC's, but generate and decode Manchester coding in your existing processors. If you can't do that?, then use ready made chips for it - like these:

http://www.rfsolutions.co.uk/acatalog/Smart_Radio_Transceiver_Chip.html
 
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mananshah93

New Member
Thanks Sir Nigel,
I want to know which is easy and better among two method you mentioned, ready made chip or generating or decoding manchester coding???
I read the datasheet of rf600t, I want to transfer the data bits from transmitter-receiver to controller...it is written that total (161 + data) bits will be sent, if I want to transfer 10 bit data (e.g 1000), what should I have to control in that chip? This 161 bits will be generated by chip??? if yes what about address??

If you have used that , can you briefly guide me??
 

Nigel Goodwin

Super Moderator
Most Helpful Member
I've never used one, but the datasheet explains everything - basically you supply it serial data (RS232 type), and the decoder outputs the same serial data.

If you're using a PIC, my tutorials show how to do Manchester coding, for various packet sizes.
 

vinayn

New Member
hi frnds i am new to this, can anyone help me that i want to do my final year project on bluetooth..so plz giv ideas,links,reports regarding on how to use bluetooth in different applications......
 

mvs sarma

Well-Known Member
hi frnds i am new to this, can anyone help me that i want to do my final year project on bluetooth..so plz giv ideas,links,reports regarding on how to use bluetooth in different applications......
you may better start a new thread rahter than use some one elses-- amounts to hijacking, vinayn. perhaps many things can be found by googling for bluetooth based projects
 
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