What's the cheapest way to link a few microcontrollers wirelessly at low speeds over short distances.
I'm looking to keep it ultra-cheap, use common discrete parts and keep it physically small. I don't care about bands and licensing so long as it works.
802.15.4/ZigBee, Bluetooth and WiFi all require an expensive coprocessor, so aren't an option.
Alternatively, are there very cheap radio modules available to hobbyists? The kind of things you find in car keyfobs and wireless thermometers, perhaps?
Would building a simple transceiver on a homebrew PCB even be practical, or will I be plagued by tuning, interference and weirdy analogue stuff?
Could something like this be driven from a microcontroller?
What about receive?
Best Answer
Infrared emitters and receivers can be used to transmit/receive data. However, interference with other devices like remote controls might be a problem. If the connection needs to be really reliable, this probably wouldn't be that great of an option. However, you might be able to find a really uncommon wavelength emitter and receiver to limit the amount of interference.
These are pretty common, and very cheap. Packs of 20 emitters for $1 and packs of 100 receivers for $13 can be found on eBay (not including shipping). Lots of electronics stores have them as well.