I'm looking for suggestions for a wireless transmitter & receiver combination. I'm basically just trying to bridge several buttons over a wireless signal(s) (i.e. send a 1 bit signal) in as small a package as possible:
- Very short range (needs to be 99% reliable at ~3 ft away, no line-of-sight).
- Low power, especially for the transmitter. I'd like to be able to send ~10,000 pulses off of a watch battery
- Very small transmitter (needs to fit inside something around 1 in^3, though I have a fair bit of flexibility on placement)
- Would like to prevent accidental cross-talk
Any ideas appreciated. If interested in the reasoning, I'm trying to build a wireless Di2 system (electronic bicycle shifting)
Best Answer
A 433MHz ASK transmitter/receiver pair should do very well at the ranges you are talking about. I have used them quite successfully in my Wicked Node and Wicked Receiver products, at hundreds of feet, so you should easily be able to use them to make it work over such a small distance. The transmitter can be quite low power because you can basically draws no current when not transmitting. The receiver on the other hand, needs to always be on and continuously outputs "data" that you have to sift through to extract actual transmissions from the noise. You could use the same exact product set to do what you want here but it will be a little bit longer than 1 inch, but you might be able to hack it into a 1 cubic inch with some creativity.