The voltages and signal timings described below are dependent on the battery voltage and are probably also impacted by temperature. While the calculator runs on a 9 V battery, internally the logic ...

A keyboard matrix circuit is a design used in most electronic musical keyboards and computer keyboards in which the key switches are connected by a grid of wires, similar to a diode matrix. This kind ...

Here’s something fun from [Chad Kapper] over on HackMakeMod: Escape Room Lockbox with the Cheap Yellow Display. You may have heard of the “cheap yellow display” (CYD), so-called due to the board’s ...

Keypad phones, believe it or not, are still in use, and there is a surprising amount of variety to choose from. Some of the phones include 4G connectivity, cameras, and are built to last. If you're ...