In my eternal quest for tiny IOT sensor nodes that are ultra low power and use radios to get telemetry data back to a gateway, I have been hanging out over on MySensors.io forum.
These guys are manic about low power nodes based on Arduino pro mini.
I bring it up because those of you experts building your own hardware might enjoy the hardware forum over there.
Ian, maybe you could use this system for your chained sensor nodes you posted about yesterday.
MySensors is an open source hardware and software community focusing on do-it-yourself home automation and Internet of Things.
We’re here to help people who’d like to create original and affordable sensors and actuators based on components like, Arduino, ESP8266, Raspberry Pi, NRF24L01+ and RFM69. Does it sound complicated? Don’t worry, we’ll explain everything.
We provide easy to follow build instructions, ready to use code examples and adaptable open source hardware designs. All of this runs on the MySensors software library for secure communication that has been battle-tested with more than 20 of the leading home automation controllers on the market.
At that power level you don’t even need a battery. Just a 2x5 indoor solar cell. These guys make highly efficient solar cells for that exact purpose. The dev board is $49 and can be integrated with any MCU for testing. Been kicking around getting one but the power output is a little low for what I need.
Self recharging drones! Would love to build one that’d work like a cross country homing pigeon. Would be interesting to see if it could navigate the continental divide if nothing else. “Hey … crap, it last checked in somewhere west of Denver, landed somewhere about 11,000 ft… guess we wait until next May to see if it thaws out and takes off again.”