How much current will your LED draw from a 2 volt battery when it has to go through a 2k Ohm resistor?Paul
The blue green component is an inductor, not a resistor. The circuit is actually a step up voltage converter, as described here, with an IC under a black blob.More about that chip here.
Hi AntroxEv,Yes you can totally use the YX8018 to control when the light turns on. If the solar cell is providing no charge it is possible to detect this situation and turn on the LED. Here is a site that explains it fairly clearly.https://ez.analog.com/adieducation/university-program/b/blogs/posts/hacking-an-led-solar-garden-light
1) as interrupt (falling mode) to wake up arduino when the solar cell is on/off