Author Topic: cheap wireless tech  (Read 521 times)

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Offline vipulan12Topic starter

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cheap wireless tech
« on: April 11, 2013, 07:30:34 PM »
hey guys, there are these cheap transmitters and receivers at Sparkfun which i plan to use for my arduino but
i want to know if it's possible to send and receive data without another micro controller(since i don't have another one)

could i set it up so that when i hit a switch (on a controller) it will release an electrical signal to the transmitter to  transmit a signal to the receiver (which is hooked up to an arduino)
that way i wont have to buy any additional hardware


also there are two of these RF transmitter and recievers, one with  315Mhz and another with 434Mhz
which one is better and why
https://www.sparkfun.com/categories/79

thanks

Offline waltr

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Re: cheap wireless tech
« Reply #1 on: April 11, 2013, 08:47:42 PM »
There is not much performance difference between 315 and 434MHz. There can be legal differences depending on which Country you live in.

These are OOK (google it) transmitter/receives. The reliably send data you really need the encode the data, Manchester encoding (google the also) is most common and a preamble is sent first to set the receivers AGC cicruit. This means that a processor at the receiver is needed.

For code check out the VirtualWire:
http://www.airspayce.com/mikem/arduino/

« Last Edit: April 11, 2013, 08:50:42 PM by waltr »

Offline vipulan12Topic starter

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Re: cheap wireless tech
« Reply #2 on: April 12, 2013, 05:30:00 PM »
okay if thats the case can i use a ATiny85 for the transmitter
https://www.sparkfun.com/products/9378

Offline waltr

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Re: cheap wireless tech
« Reply #3 on: April 12, 2013, 06:10:50 PM »
That should work for the transmitter encoding and may even work for the receiver decoding.
It doesn't have a UART but 'bit-banging' serial out is pretty easy. The receiver would be harder so an arduino with its UART is easier to code.

Offline vipulan12Topic starter

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Re: cheap wireless tech
« Reply #4 on: April 13, 2013, 10:43:23 AM »
what do you mean by bit banging serial

Offline waltr

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Re: cheap wireless tech
« Reply #5 on: April 13, 2013, 05:52:54 PM »
what do you mean by bit banging serial
Software timing sets/clears an output pin to produce a serial data stream.
Google the term for more info

Offline waltr

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Re: cheap wireless tech
« Reply #6 on: April 14, 2013, 01:57:09 PM »
Here is a link to a SparkFun Forum topic that matches what you want to do.
https://forum.sparkfun.com/viewtopic.php?f=14&t=35193

 


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