Oscilloscopes are excellent tools to have when working with electronics, and while there are miniature versions available, most are meant for benchtop use. This one, however, is actually made in the form of a pen, with a probe built into the tip of the unit, and a clip that attaches to the other lead.
While a pen-type oscillate isn’t an entirely new concept, the system here is self-contained. A tiny OLED screen on the side displays signal readings, and +/- buttons modify vertical sensitivity, sweep speed, and trigger slope. It can take internal readings of its 2 AAA batteries — which give it a 12 hour run time — and also features a voltmeter mode. The device is controlled by an ATmega328P microcontroller, and was programmed in the Arduino IDE.
Perhaps the coolest feature of this build, though, is the enclosure made from a modified chopsticks and spoon case originally emblazoned with, “Today Is Nice Day” on it. While the clear covering was painted black with the exception of an area for the OLED to shine through, maybe having a portable oscilloscope around will indeed make today nicer than the last for the device’s creator. An overview of the build is seen in the video, and more details can be found in this write-up [translated].