UPDATE(3/6/23): Nessie Circuits has opened its crowdfunding campaign for Riotee, a low-power family of devices targeting the battery-free Internet of Things (IoT) — with pricing starting at $55 plus shipping for a surface-mount Riotee Module offering battery-free Bluetooth Low Energy connectivity.
Those looking for an easier introduction into the Riotee range can opt for the Riotee Board, an all-in-one development board which pairs a Riotee Module with a Raspberry Pi RP2040 microcontroller, for $89; add-on shields for the Riotee Board are priced at $35 to add solar panels, additional capacitors, or sensors.
The campaign is now live on Crowd Supply, with a $19,000 goal.
Original article continues below.
German low-power electronics specialist Nessie Circuits is preparing to launch an open source development platform specifically targeting the battery-free Internet of Things (IoT): the Riotee Module with carrier board and accessory shields.
"Every year millions of new portable IoT devices are sold, and they are all powered by batteries. Regularly replacing millions of batteries is inconvenient, expensive, and bad for the environment," Nessie Circuits' Kai Geissdoerfer and Marco Zimmerling explain. "We believe it's time for a responsible Internet of Things that leaves batteries behind in favor of renewable energy and sustainable energy storage."
To actually approach that goal, though, the technology has to be made accessible — which is where Nessie Circuits is hoping to help with the Riotee platform, a collection of boards focused around the Riotee Module. "The Riotee Module is the heart of our product," the company explains. "It integrates energy harvesting, energy storage, power management, non-volatile memory, a powerful [Arm] Cortex-M4 processor, and a 2.4-GHz, BLE [Bluetooth Low Energy]-compatible radio into a tiny module with the footprint of a postage stamp. Solder it to a PCB full of sensors, peripherals, and whatever else you need for your application. Add a solar panel, and you have a fully functional, battery-free device!"
The module is based on a Nordic Semi nRF52833 system-on-chip, giving it a single 64MHz Arm Cortex-M4 CPU core, 128kB of RAM, 512kB of flash memory, and a 2.4GHz BLE-capable radio. Elsewhere on the module is 128kB of Texas Instruments non-volatile FRAM, the contents of which survives the loss of power, an ultra-low-power Ambiq real-time clock (RTC), a 44µF capacitor to store harvested energy, and a Maxim Integrated boost converter with software-defined maximum power-point tracking and energy measurement.
While the company will be making the module, which features castellated headers to three sides for surface-mount installation, available on its own, it will also be bundling it with a carrier dubbed the Riotee Board. Once installed in the breakout, the Riotee Module gains 2.54mm pin headers for 10 general-purpose input/output (GPIO) pins, a USB Type-C connector for programming and data, interestingly driven by a Raspberry Pi RP2040 microcontroller, and what at first glance looks like a connector for a battery — but which is, in fact, designed for use with a solar panel.
For those looking to solar harvesting as a power source, Nessie Circuits has also announced the Riotee Solar Shield which, as the name implies, is designed to sit atop the Riotee Board and provide power from four solar cells — any of which can be disabled to test projects' performance when less power is available. A Capacitor Shield, meanwhile, adds additional energy storage, and a Sensor Shield packs a Sensirion SHTC3 temperature and humidity sensor, a Bosch Sensortec BMA400 accelerometer, and a Vesper VM1010 analog microphone on board.
"Combine a Riotee Board with a Sensor Shield and a Solar Shield, and you’ve got yourself a weather station that can send environmental-sensor data to the cloud for decades without ever needing a battery replacement," the company claims. "Or, how about wedging our tiny Riotee Module into a battery-free fitness tracker that measures oxygen saturation and counts steps while drawing power from body heat or solar energy? Want to teach students the basics of sustainable electronics and renewable energy? Our Arduino-based software will help you do so using hands-on examples. And of course, if you’re a researcher working on advanced topics like machine learning, mesh networking, or intermittent computing, Riotee is the ideal platform to help you explore the latest scientific advancements in the field."
The company is planning to launch a crowdfunding campaign on Crowd Supply in the near future, and has promised that all software will be available under an open source license on its GitHub repository by the time the campaign goes live.
The company has already published hardware design files for the Riotee Board, the shields, and a module-programming Riotee Probe under the CERN Open Hardware License (OHL) Version 2 - Weakly Reciprocal license, but had not announced any plan to open the Riotee Module's design at the time of writing.