Based on Energy Micro's low cost starter development kit, the demonstration relies on Linear Technology's LTC3588 piezoelectric energy harvesting power supply and Energy Micro's ARM Cortex-M3 enabled EFM32 Gecko microcontroller to create a wireless sensor node acquiring data from a 3-axis accelerometer and transmitting it over a Zigbee RF transceiver.

The energy harvested from a piezoelectric transducer is stored on a capacitor bank for later consumption by the accelerometer and radio according to the MCU's optimized sequencing software.  The EFM32 Gecko spends the majority of its time in sleep mode until woken by the LTC3588's 'power good' signal.  The MCU monitors energy levels at all times to ensure total circuit consumption stays below harvested energy levels.


"Using sustainable kinetic, photovoltaic and thermal energy sources to power microcontrollers requires energy harvesting power supplies capable of both very high efficiency conversion and very low quiescent power loss, " said Don Paulus, Vice President & General Manager of Power Products at Linear Technology.  "At the same time, microcontrollers have to play their part, offering very low power operating modes and the application software flexibility to make the best use of the harvested energy - the EFM32 Gecko MCU provides such attributes."

Øyvind Janbu, CTO, Energy Micro said, "Linear Technology's ultralow power energy harvesting power supplies match perfectly well with the needs of the EFM32's energy modes.  This demonstration illustrates the tremendous opportunities open to designers of smarter energy harvesting products.  There is no penalty for using 32-bit microcontrollers in such applications, the component technology already exists and it's available off-the-shelf."

Further information on the energy harvesting solution from Linear Technology and Energy Micro can be found at www.energymicro.com/energyharvesting