But as an added twist, the oscillator is keyed by an ATtiny13 hooked to an LM335 temperature sensor, sending out the Celsius and Fahrenheit temperature in Morse every 30 seconds or so.

Electrical engineers have developed a temperature sensor that runs on only 113 picowatts of power -- 628 times lower power than the state of the art and about 10 billion times smaller than a watt ...