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Hey im trying to make a simple wireless on/off switch that can be powered by AA battery's and i would like to make it from scratch...
$9 transmitter and receiver setnever used it though. EDIT, eh, links backwards, but you get the idea.
it's a good kit but it's not a switch. but it needs a microcontroler on the other end.
What the transmitter 'sees' on its data pin is what the receiver outputs on its data pin
Quote from: blackbeard on July 29, 2010, 06:06:16 PMit's a good kit but it's not a switch. but it needs a microcontroler on the other end.No it doesn't. I'll play the part of Soeren here and inform that for such a trivial task as this, no micro controller is needed. For one thingQuoteWhat the transmitter 'sees' on its data pin is what the receiver outputs on its data pin So holding the data pin on transmitter high or low will keep the receiver high or low. The problem is they don't say what the receiver does if the transmitter is off. My guess is that it enters a high-impedance state, and floats the pin. But, that would be great, because then you could pull it down, and always have the transmitter transmit a 1 (tie TX to VCC) and whenever the transmitter turns on, the receiver would pull the data pin high. Vola, a wireless switch. But if not, there are some clever ways to get the message across using circuits. You could have a 555 rigged to generate two different frequencies at the push of a button, and have a filter at the receiver end to filter out the 'off' frequency, and pass the 'on' frequency to keep a cap charged holding the gate of a transistor in it's on region. That's just off the top of my head. Soeren will have better ideas i'm sure.
So you have those radios? So if the transmitter is completely unpowered, what is the receiver doing?
When it's 'going wonky' have you tried pulling it low with a resistor to see if it's just going into a high- Z state?
In that case, Google up how those little buttons on car keys can turn on/off a car alarm. I'm sure you can probably use the same design.
I kinda think IR would be the best, it costs like... 20 cents.
Generally you are looking at your computer while switching it on and off
Also kinda why TV remotes aren't RF, because there really is no need to
Some TV remotes are RF.