Time aware solar light

This application detects the absence/presence of daylight and uses this to estimate the time of day. The time of day is used to start (and stop) an energy saving mode. During the energy saving mode the light is turned off to prevent exhausting the battery. The battery is charged during daylight. The battery is used to turn on the light during darkness. Without the energy saving mode, the battery is exhausted to soon (before the next day). Implementing an energy saving mode is the answer to this problem.


The main scheme consists of four subschemes. Day light recognition, presets, charger as inputs for the Lightcontrol.

Day light reconition

This subscheme detects the absence and presence of daylight and uses it to estimate the time of day.


The user sets the energy saving time. The energy saving period starts a few hours before the set time. The energy saving period ends a few hours after the set time.


First charge the battery fast with high current, at the end charge the battery slow with low current.


Turn the light on and off, depending on the energy saving mode, the detected light and the status of the battery.



Prepared for device: ST72251G2 other devices possible by reconnecting I/O pins.