Sensor walkabout
On a normal day, I walk about 2 blocks from the subway to my apartment. These are sensors that I see every day.
This sensor reads how many rides you have left on your metrocard. Magnetic strip reader.
Feed the machine bills and it knows which one you put in. Scans the magnetic ink and looks for patterns.
I looked up how bills are scanned and read by machines like this, and found this interesting website about counterfeiting, the most relevant quote re-posted here: “U.S. paper money is printed with magnetic ink, but that’s also used for many fraudulent bills. But on real bills, the ink is distributed in a consistent pattern whose magnetic resonance can be mapped.”
Touch the screen in designated spots to navigate. Spots change.
The glass touch screens work a little differently than LCD touch technology. Read more here. The glass screen is a touch sensor that is placed over the LCD.
Senses whether or not a product has been purchased.
This is an RFID (Radio Frequency Identificaion) Asset Management System. A small sticker or strip is embedded with a passive tag; the reader is is installed at the exit. Once you’ve paid, the tag ID on the product is deactivated from the system database, and the reader will not recognize the tag. More uses here.
Magnetic strip on your credit card is read.
Micro-camera that senses light and converts it to an image
This micro-camera probably only uses one CCD (Charge Coupled Device) or CMOS (active pixel sensor) to sense light and convert it into an image. Used here for security purposes. Someone buzzes an apartment, and the resident can see who it is. I’ve worked with similar micro-cameras in live video for performance. There is also a microphone behind the panel. It senses sound!
This sprinkler is embedded in the ceiling.
I cannot tell how this sprinkler senses the world, but old-fashioned sprinklers are triggered when mercury in a small glass vial expands to the point that it breaks the vial, causing the sprinkler head to fall, which opens the valve to the water system. This might have some high-tech chip in it that detects heat– but knowing the building manager, probably not.