need help with rf trans/receivers

Thread Starter

rob vickers

Joined Jun 26, 2008
4
im working on a project that seems like it would be incredibly simple, but having trouble figuring a few things out. have some knowledge in comp programming, but none in electronics.
i need to use multiple rf transmitters all sending the same receiver. was thinking of using the MC145028 (but im not sure if thats what im looking for). After the reciever "hears" a transmission from a certain transmitter, it makes a beep. i dont want the receiver to "beep" from hearing that transmitter again for a certain amount of time. any suggestions or insults, haha?
 

thingmaker3

Joined May 16, 2005
5,084
Golly, I've used up all my good insults already today. Guess you'll have to settle for a suggestion.:)

You might want to look into a micro processor for your project. If each transmitter can send a specific binary number, the micro processor in the receiver could handle the rest of your requirements.
 

John Luciani

Joined Apr 3, 2007
477
A very simple way would be to use a uC and prebuilt radio (it can get expensive).
Some of the prebuilt radios, like the MaxStream XBee ($23), integrate an A/D
and digital I/O. An XBee may be able to perform all of the functions that you
require without a uC.

I have developed some ATmega168 development tools that integrate an XBee.
The tools are compatible with the Arduino environment. See http://www.wiblocks.com.

(* jcl *)
 

Thread Starter

rob vickers

Joined Jun 26, 2008
4
thingmaker, if each of the transmitters sent a separate binary number, im guessing i would have to put the transmitters on timers so the reciever can actually hear which one is transmitting? that seems like that would work. as for the microprocessor, im guessing you just give those computer code and they tell the outputs what to do?
 

John Luciani

Joined Apr 3, 2007
477
john, ill look into the xbee thing, but this system CAN NOT be expensive at all.
I am not sure of your definition of expensive but the XBees are $19-$23 each.
You are paying for ease of integration, the RF design and the Zigbee networking
protocol.

You could also look at the RF systems on a chip from TI (8051 uC + Radio).

I forgot to mention the book "Making Things Talk" from O'Reilly. This book discusses a wide range of communications methods including wireless.

(* jcl *)
 

SgtWookie

Joined Jul 17, 2007
22,210
Well, you might take a look at rfPIC's from Microchip. Programmable uC's with the capability to transmit/receive. They're roughly $2.50 each. You could program them to transmit a unique code in very short bursts with different pulse repetition times, although it would be better to have the "master" interrogate the "slaves" for status reports.
 

Thread Starter

rob vickers

Joined Jun 26, 2008
4
yea, i read one of your other comments about the master/slave thing, where im guessing the receiver is the master and the transmitters are the slaves. i would prefer if all the transmitters did was send out a signal (this signal would be different for different transmitters) and once a receiver hears that signal, he reports it, but doesnt report hearing that same signal (even though he might)for a few minutes or so.
 
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