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Author Topic: Transmitter/Receiver Help  (Read 750 times)

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Offline arigidTopic starter

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Transmitter/Receiver Help
« on: December 11, 2012, 06:24:25 AM »
Hi, I have been working on a project, where a change in state of a limit switch is used, to send a signal from a transmitter to a receiver.
The receiver is to be used to just activate a buzzer.
Can this be done without using a micro!?
What kind of signal does the receiver give at the data pin.?
Thanks for any help in advance.

Offline billhowl

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Re: Transmitter/Receiver Help
« Reply #1 on: December 11, 2012, 09:49:22 AM »

Offline jwatte

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Re: Transmitter/Receiver Help
« Reply #2 on: December 11, 2012, 11:41:04 AM »
Hi, I have been working on a project, where a change in state of a limit switch is used, to send a signal from a transmitter to a receiver.
The receiver is to be used to just activate a buzzer.
Can this be done without using a micro!?

Yes! Just run a wire from a battery to a "normally open" limit switch, then from the limit switch to a buzzer, and then back to the battery.

If you need wireless, then some "remote relay" function like you suggest could be used.

Offline Soeren

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Re: Transmitter/Receiver Help
« Reply #3 on: December 11, 2012, 03:03:51 PM »
Hi,

I have been working on a project, where a change in state of a limit switch is used, to send a signal from a transmitter to a receiver.
The receiver is to be used to just activate a buzzer.
Get a cheap wireless doorbell and activate the button via a capacitor (of say 1..10µF) and you're done. You won't be able to make it any cheaper yourself.

Check the range of the doorbell (and subtract 20..30% to be sure).
If this is for something critical, you should get a proper system.
Regards,
Søren

A rather fast and fairly heavy robot with quite large wheels needs what? A lot of power?
Please remember...
Engineering is based on numbers - not adjectives

Offline arigidTopic starter

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Re: Transmitter/Receiver Help
« Reply #4 on: December 11, 2012, 04:15:54 PM »
Thank you for the reply guys,
@billhowl, that is actually pretty good, and i am definitely buying it.

It was actually a college project and obviously has to be more of something that you make from the parts available,
I bought the Sparkfun Transmitter/receiver pair(434MHz).
Could it be possible to hook up the transmitter, such that it takes in a digital input(limit switch), without using a micro.
And send a signal to the receiver which gives a digital output!?


Offline Soeren

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Re: Transmitter/Receiver Help
« Reply #5 on: December 11, 2012, 05:44:24 PM »
Hi,

I bought the Sparkfun Transmitter/receiver pair(434MHz).
Could it be possible to hook up the transmitter, such that it takes in a digital input(limit switch), without using a micro.
And send a signal to the receiver which gives a digital output!?
Yes, either use a monoflop to pulse the transmitter input high for a given time, or the same, but modulate the input with eg. 1..2kHz for that  period - A 4093 (and a few passives) is all it takes.
On the receiver side look for a signal that mimicks the transmitted signal.
If you need to discriminate in crowded air, a little more circuitry could be used to generate a more stable frequency of the modulation (x-tal or ceramic resonator) and a PLL tone decoder (like LM567) at the receiver end can be used to confirm the signal.

Want it fancier? Transmit one or a few DTMF tones instead, but that's more circuitry in both ends.
Regards,
Søren

A rather fast and fairly heavy robot with quite large wheels needs what? A lot of power?
Please remember...
Engineering is based on numbers - not adjectives

 


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