Silicon Laboratories has a reference for a solar-powered wireless sensor.
The reference design consists of 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 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 displays data from up to four sensor nodes.
The thin film battery used in the energy harvesting reference design has a capacity of 0.7mAh.
In direct sunlight, the battery can be recharged fully in only 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.
Other harvested energy sources can be used and a bypass connector allows developers to bypass the solar cell and use other energy harvesting sources such as vibration (piezoelectric), thermal and RF.
Originally posted 2011-06-03 09:19:44.