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Author Topic: Wireless Not working..Please help  (Read 703 times)

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Offline RecklesSTopic starter

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Wireless Not working..Please help
« on: August 19, 2009, 11:00:10 PM »
I need help with my wireless module..
Im using a wirelsss 433MHz ASK module for transmitting data wirelessly..
Im packaging my data serially and sending it to the appropriate pin on the transmitter through the serial port of my computer.But i am not receiving any data on the receiver end..
I have checked all connections..When i send the data thru a wire,it works fine..my bot recieves the data perfectly and operates as directed...bt with wireless it just isnt working..

I want to know what could be the problem..Im using a hellically coiled breadboard wire(17cm long) as the antenna..
Do i need to use the Encoder and Decoder ICs???

Offline BEAMer

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Re: Wireless Not working..Please help
« Reply #1 on: August 20, 2009, 10:46:20 AM »
Hi,


 http://www.societyofrobots.com/robotforum/index.php?topic=7125.msg55355#msg55355

I have answered to the same question in this post. Check it out....

BEAMer

Offline RecklesSTopic starter

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Re: Wireless Not working..Please help
« Reply #2 on: August 21, 2009, 10:38:37 AM »
while reading on the net..i realized that we have to use Holtek ICs for encoding and decoding the signal while sending information through rf..
can u suggest a way to eliminate the ics..i.e. i could encode the information on my pc and then send it through usart and then through rf....???

basically i want this...

byte(information)   ->   encoding(manchester or something else)   ->  usart   ->   rf transmitter  ->  AIR  ->  rf receiver -> usart  ->  decoding   ->   atmega


Offline BEAMer

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Re: Wireless Not working..Please help
« Reply #3 on: August 23, 2009, 11:03:34 AM »
I have tried using the modules without the encoder and decoder pairs and they seem to pick lot of noise... They become so unreliable, that no application can be built on them. However you can eliminate the noise by sending the data multiple times on the Tx and on the reciever, you can see how many times you got the correct data and the wrong data and take a decision. you can very well do this by writing an app on the computer side and the reciever validation program on a microcontroller on the receiver end.

This same functionality has been implemented on the Holtek ICs, so i just used them and they are so reliable. They even have address bits so as to avoid interference...

BEAMer

Offline BEAMer

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Re: Wireless Not working..Please help
« Reply #4 on: August 23, 2009, 11:05:28 AM »
Try reading the algorithm implemented on the Holtek ics. That shd give you a very good idea. Its given in the datasheet.

BEAMer

 


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