> For the complete documentation index, see [llms.txt](https://learn.arduinosa.co.za/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://learn.arduinosa.co.za/sensor-kits/37-in-1-sensor-kit/light-cup.md).

# Light Cup

![](/files/-MS2OVC_Zaa_ESpNQfxT)

This module incorporates a mercury tilt switch and clear red LED. ‘G’ is the common connection to the LED cathode and one terminal of the switch. ‘S’ is the other switch contact and ‘L’ connects to the LED anode (a series resister is required for the LED, 220 ohms for example). The ‘+’ pin connects to a 10 K ohm pullup resistor connected to ‘S’ of the switch.