Today I’ve installed a second version of shofanduino, one with a digital sensor. The old (analog) sensor is replaced with the digital one and this is what the analog sensor looks like after a couple of months:

It was cleaned a couple of months ago when I noticed it was giving more noisy readings. The noisy readings didn’t stop after cleaning and you can see why in the image: lots of dirt on the sensor itself (the one with the protective blue casing) and white stuff on the contacts. That can’t be good!

Below you can see the difference in sensor readings (both taken at the same time). You can see that the second one is much smoother.