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#180354
I'm thinking of building an experience which allows a user to learn more about a physical object by pressing an adjacent button. Upon press, a TV will play a video describing the piece in more detail. Think of a large wall of posters (each with their own button) with a shared screen in the middle. These posters must be quickly interchangeable so a wireless solution is a must. Also, the transmitting device should run off a battery and be inexpensive.

I've used Bluetooth LE in the past and am confident I can easily use something like http://www.blueradios.com/hardware_sensors.htm or https://store.ti.com/cc2650stk.aspx to accomplish my task. But at ~ $30 a pop, that's getting to be an expensive project.

I think I'd like to try RF transmitters and receivers (https://www.sparkfun.com/products/10534, https://www.sparkfun.com/products/10532) but I'm not sure if they're the right fit for my project. In the given examples for each product, it looks like both the transmitter and receiver require a micro controller. Is it possible to use the transmitter without a controller and still produce a unique signal for a receiver?

Thoughts? Any other approaches?
#180366
joelongstreet wrote:Is it possible to use the transmitter without a controller and still produce a unique signal for a receiver?
I think you're on the cheapest cost RF approach, but no I don't see any good way to use these simple AM Tx/Rx pairs w/o some form of "controller". You may want to look at Adafruit's 4 "key" fob Tx/Rx set. IIRC there isn't a micro-controller in them but rather a encoder/decoder set (PT 2262/2272) that could do a lot more than just 4 unique IDs. But you'd have to hack their PCBs or come up with one of your own. I'm not sure that's any easier (though likely less $$s) than using something like a Trinket connected to the Tx end to send a unique message/ID. Something more robust would be connected to the Rx end to run your video on demand.
http://www.adafruit.com/products/1095
http://www.adafruit.com/products/1501

Then perhaps there's something in the acoustic/ultrasonic line that could work for less $$s. Perhaps a form of DTMF ?

But tell me why "quickly inter-changable" precludes some really simple wired idea ? How many panels are they to be ? Spaced over what range of distances from the main video display ? For instance, why not use RJ45 jacks and plugs and wiring ? Why not a wired connection that gets made via whatever physical connection there is ... the one that's holds the "poster" to it's wall ?
#180369
The RN42 is about $15 each and easy to use, but I don't know its power consumption.

You could use those transmit/receive modules with multiple transmitters, each being modulated at a different audio frequency, maybe with a 555 or something like that. The receiver would then only need to measure the pulse frequency to determine which transmitter was sending. That's a pretty cheap option as long as you don't care about problems if multiple buttons are pushed at once.