Silicon Laboratories Inc. has introduced a wireless sensor node solution powered by a solar energy harvesting source. The new reference design is optimized to assist implementation of self-sustaining, ultra-low-power wireless sensor networks for home and building automation, security systems, industrial control applications, medical monitoring devices, asset tracking systems and infrastructure and agricultural monitoring systems.
Silicon Labs' wireless energy harvesting system is based on its Si10xx wireless microcontroller (MCU) family. It includes wireless network and USB software and a complete circuit design with RF layout, bill of materials (BOM), schematics and Gerber files. The design consists of three components:
- A solar-powered wireless sensor node that measures temperature, light level and charge level, using an Si10xx wireless MCU to control the sensor system and transmit data wirelessly and a thin-film battery to store harvested energy.
- A wireless USB adapter that connects the wireless sensor node to a PC for displaying sensor data; the adapter features Silicon Labs’ Si4431 EZRadioPRO® transceiver with an MCU running USB-HID class software and EZMac® wireless software stack.
- A wireless sensor network GUI that displays data from up to four sensor nodes.
The thin film battery used in the energy harvesting reference design has a capacity of 0.7 mAh. In direct sunlight, the battery can fully recharged in two hours. While in sleep mode, the wireless sensor node will retain a charge for 7,000 hours. If the wireless system is transmitting continuously, it will operate non-stop for about three hours, although it is designed to constantly recharge itself at an appropriate level to keep the thin-film battery from completely discharging.
Pricing and Availability
Silicon Labs energy harvesting reference design is available now and priced at $45 (USD).
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