Simple RF remote / kill switch

idea: simple remote control for the robot using some cheap commercial RF transmitter (keychain size, like for cars). The receiving device will be some 3-4 pin module under an inch size. It may be used as a kill switch as well as to send 2-3 other simple commands. I wonder if this could be done under $20?

SparkFun carries something like what you’re talking about, the Nordic FOB. The transmitter alone will cost you $25, plus another $20 for a receiver.


I think it is manageable. Look at:

sold as a RC control unit plugin attachment (using a spare channel, etc).