MORE ABOUT IoT

How much power does my connected device use? Does its sleep mode conform to the manufacturer's documentation? How long will the CR2032 battery last? If you're asking yourself these sorts of questions, here is a regulated power supply, dubbed MicroSupply, in the form of an Arduino shield, which measures very small currents. Thanks to a link with a PC application, you can see and log the power consumption of your device.

Using the PiJuice from PiSupply you can use your Raspberry Pi without a mains power adapter. Or for a while anyway. It has been designed as a UPS (Uninterruptable Power Supply) and can ride through several hours. The PiJuice is configured as a HAT for the Raspberry Pi and plugs without any problems onto the 40-pin RPi header.

A switched off device does not reduce battery life, but is does not work either. Now, an energy-efficient system that is always on alert can turn on devices when needed. This saves energy for applications in IoT network. Researchers from the Arbabian lab at Stanford University have developed an alarm receiver that turns on a device via incoming ultrasonic signals. These work on a significantly smaller wavelength and switch from radio waves to ultrasound. This system detects a wake-up action of 1 nanowatt signal power.