I would like to have a small, lightweight chip (perhaps a ATMEGA328P-PU chip?) programmed to work with an attached altimeter and an electronic switch.
The concept is to have a drone carry it, and only when the "device" senses it is a certain distance from where it was "turned on", it then opens a switch that allows battery current to flow to a radio-receiver., turning that receiver "on" (the receiver is not part of the device to be built.
I would need a way to download it onto other chips if and when someone wants a few dozen of the devices.
I suppose it could be done differently, using an iPhone and a persistent bluetooth connection which keeps the electrical switch "open", which, when it the bluetooth connection is "broken" (for example, when the drone flies up 100 feet), it then closes a switch which allows battery current to flow to a radio-receiver, turning that receiver "on".
I'm not sure which will work the best.