A N 5 8 8
8
Rev. 0.2
8. Additional Information
If the power select switch is in the SOLAR position and the Energy Harvesting Node Board is exposed to at least
200 lx for several hours per day, the total charge in the system should never drop below 75%. If the system will be
stored in a dark environment for several days (e.g., when traveling, etc), then it is best to place the power select
switch in the OFF position. The system will hold its charge indefinitely in the OFF position. If the energy in the
system ever gets depleted, then it may be quickly charged (30 minutes) by plugging in a ToolStick Base Adapter
and setting the power source switch to USB. Figure 10 shows approximate charging times for a fully depleted
system under various charging conditions.
Figure 10. Charging Time For Various Charging Conditions
The energy harvesting Node board may be used for RF development with the Si1012. The ToolStick Base adapter,
which allows connection to the Silicon Laboratories IDE, is supplied in the kit. For firmware source code or
additional information, please visit the Energy Harvesting Page on the Silicon Laboratories website.
http://www.silabs.com/Energy-Harvesting
Electric
Light
200 Lux
Office
Window
1000 Lux
Direct
Sunlight
100K Lux
USB
Charging
30 minutes
2 hours
6 hours
24 hours
