Problem with photo interrupter

Can’t get this grove component to work:

seeedstudio.com/wiki/Grove_- … _Interrupt

When connected to the stem shield, the red LED comes on, but no adjustment of the potentiometer will cause it to turn off again.
Am I correct in assuming it should be used with a digital input?

Am I missing something?

Thanks
Duncan

Hey , you need adjust the potentiometer with a crosshead screwdriver when you first use it.

And this one use the digital 6 pin.