This sensor utilizes light emitter and reflection to detect dust concertration, which features high accuracy, good consistency and stability. It can detect concertration of PM2.5, cigarette smoke, ...

Of all the ways to open up a lock, there are some tried and true methods. Keys, combinations, RFIDs, picks, and explosives have all had their time and place, but now someone else wants to try somet… ...

If you have an Arduino that can act as a keyboard for a PC, the code almost writes itself. [Rootsaid] uses a specific library for the PAJ7620 and another — Nicohood — for sending media keys.