In most keypads, pressing a key closes a contact that bridges two lines in an xy matrix. If you use a microcontroller to detect a key closure, checking the states of (x+y) lines requires an equal ...

[R-B] designed a 555 timer circuit to scan a keypad. Keypads are common interfaces for small projects and require row and column scanning by a microcontroller. [R-B’s] setup allows you to reduce the ...

Traditionally, interfacing a microcontroller with an n-by-m keypad required n + m of the microcontroller's I/O pins for keypad scanning. Keypad designs that conserve microcontroller pins have been ...

If you enjoy building electronic circuits, projects and devices, you might be interested in a new component launched by Adafruit this week in the form of the new Adafruit 4×4 elastomer keypad. The ...

This circuit uses Microchip’s PIC16C71, an 8-bit microcontroller, to create a digital voltmeter with an LED display and a keypad. To view the application note, click on the URL below. Circuit selected ...

Many laptops eschew the numeric keypad to free up space, and some desktop keyboards have taken on the trend, too. If you want a specialised numeric entry device and have absolutely no interest in ...

If you would like to build your very own Macropad shortcut keypad you may be interested in a new project published to the Hackster.io website by member Naveen. The builder is classed as an ...