Now, the venerable ultrasonic sensor joins the gallery of classics given a size change treatment, like the 555 timer we’ve seen two different takes on, or perhaps that one Arduino Uno.

[Jordan’s] sensor includes just a single pixel. The sensor is really just an infrared photodiode inside of a tube. The diode is connected to an analog input pin on an Arduino.

Arduino enthusiasts may be interested in a new single pixel scanning camera which is powered by an Arduino Uno combined with a TCS34725 sensor available from online stores such as Adafruit.