Now to the complete schematic of the Grove-mini PIR motion ... Moreover, the S16-L221D sensor lets you add a light dependent resistor (LDR). It is not very practical in this Grove-mini PIR motion ...

and when attached to a glove it provides a finger sensor without the fuss. The amount of light reaching the LDR from the LED decreases as the pipe is bent, and with a simple divider circuit a ...