Norwegian healthcare-focused Internet of Things (IoT) specialist ONiO has unveiled ONiO.zero, an ultra-low-power RISC-V-based microcontroller capable of operating wholly from harvested energy — without needing a battery, capacitor, or any other form of energy storage.

"ONiO.zero is an ultra-low-power wireless MCU that uses energy harvesting technology," the company writes of its creation. "This means that the ONiO.zero solely operate on energy from its surroundings. No coin cell, no supercap, no lithium, no battery at all — but still a ton of power.

"Battery based solutions come with the inevitable caveat of battery replacement, which translates to an incremental cost, throughout their ownership. ONiO.zero circumvents this pain point and slashes the cost of ownership. It can be used to power sensors and devices for years, without having to spare a thought about maintenance — deploy and forget. ONiO.zero is self-powered and supports a wide range of power sources from multi-frequency RF bands supporting GSM and ISM to optional external sources like solar, piezoelectric, thermal and voltaic cells."

The microcontroller itself is based on the free and open source RISC-V instruction set architecture — specifically, RV32EMC — running at up to 24MHz when fed 1.8V. The controller also operates at lower voltages, when required: 1V gets you 6MHz, 0.8V gets you 1MHz, and the chip will continue to run - albeit at ever-decreasing speeds - as low as 450mV, the company claims. There's 1kB of mask ROM and 2kB of RAM included, along with 8-32kB of ultra-low-power flash storage capable of 100,000 write cycles and readable down to 850mV.

The ONiO.zero also includes a crystal-free Bluetooth Low Energy (BLE) transmitter capable of operating at voltages as low as 850mV, an IEEE 802.15.4 ultra-wide-band (UWB) transmitter operating in the 3.5-10GHz band, and an optional 433MHz MICS radio transmitter for industrial, scientific, and medical (ISM) band use.

The compact chip can run at up to 24MHz, depending on available power. (📷: ONiO)

The chip's energy comes courtesy of an internal radio-frequency rectifier, harvesting power from the 800/900/1800 and 1900/2400MHz bands (ISM and GSM). For environments without enough radio-frequency energy to reliably power the chip, the "internal power factory" supports photovoltaic cells down to 400mV, piezoelectric, and thermal sources from 1.8V to 3.6V.

More information on ONiO.zero is available in the datasheet, released upon application on the official product page.