Proving the Business Case for the Internet of Things

Renesas kit aids development of energy-harvesting devices

Steve Rogerson
November 6, 2019

Japanese electronics company Renesas has introduced energy-harvesting embedded controllers and an evaluation kit that supports the development of battery maintenance-free IoT equipment.
The RE Family is based on Renesas’ proprietary silicon on thin buried oxide (SOTB) process technology, which reduces power consumption in both the active and standby states, eliminating the need for battery replacement or recharging.
The evaluation kit lets users working with the RE01 group of devices jump start system evaluations for energy-harvesting applications.
“Energy harvesting eliminates the labour and costs associated with battery maintenance and is a key contributor to environmental conservation,” said Hiroto Nitta, senior vice president at Renesas. “I am extremely pleased that Renesas’ technology innovation with SOTB has enabled these alternative energy solutions and, with the new RE01 evaluation kit, Renesas will be making it possible for engineers around the world to quickly start the evaluation. We hope this will accelerate the spread of IoT equipment powered by energy harvesting.”
The kit includes an evaluation board with an RE01 embedded controller, an interface for the energy-harvesting device and a rechargeable battery interface. There is also an Arduino-compatible interface for easy expansion and evaluation of sensor boards and a Pmod connector to expand and evaluate wireless functionality.
In addition, there is a low-power MIP LCD expansion board so users can evaluate display functions faster. The kit also contains sample code and application notes that serve as references for a power management design that eliminates the need for battery maintenance, and driver software that supports CMSIS, Arm’s Cortex microcontroller software interface standard.
Sample code for low-power analogue-to-digital converters, digital filter and FFT (fast Fourier transform) routines, 2D graphics MIP LCDs, and secure boot and secure firmware update functions for improved security are available. With these features, this kit makes it possible to adopt energy harvesting based on RE01 devices at the system level and should accelerate the development of equipment that does not require battery maintenance.
IAR Embedded Workbench for Arm, which can use the IAR C/C++ compiler, and E2 Studio, which can use the free GNU compiler, are available as the developmental environment.
The SOTB process technology lets users simultaneously achieve low active current, low standby current and high-speed operation at low voltage. The RE01’s 32bit CPU core helps users implement intelligent functions in equipment powered by low levels of harvested energy through ambient energy such as light, vibration or fluid flow.
The RE01 embedded controllers are based on the Arm Cortex-M0+ core, which can operate at clock frequencies up to 64MHz, and provide up to 1.5Mbyte of low-power flash memory and 256kbyte of SRAM. The RE01 can operate at voltages down to1.62V and the line includes three package versions – a 156-pin WLBGA package, a 144-pin LQFP package and a 100-pin LQFP package.
The RE01 also includes an energy harvesting control circuit, a low-power 14bit analogue-to-digital converter, and a low-power circuit that can rotate, enlarge or invert graphics data.
These embedded controllers make it possible for applications to perform accurate sensing and data judgement by excluding noise from signal data when they are used as biological monitors or in outdoor environmental sensing applications. By eliminating the need for battery maintenance in a wide range of applications, they can contribute to the increasingly widespread use of IoT equipment, such as wearables, without the inconvenience of recharging batteries, and sensing applications for homes, buildings, factories and farms, where manual changing or recharging of batteries is difficult.
Renesas says it will continue expanding the RE family beyond 2020 with more members including small memory sizes with up to 256kbyte of flash memory.