Switch S1 is an ordinary power on/off switch. Finally, resistor R4 determines the operating current of the white LED (LED 1 – LED 20) assembly. No-load voltage of the solar panel is near 7.2Volt. When ...

As explained by Arduino to Go, each color band on the resistor corresponds to a number but this can differ depending on the band's placement. It's not complicated, but the sheer number of colors ...