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 ...

16-button keypads have a clever method of encoding their data into 8 pins. Pins are mapped to four rows and four columns on the keypad. A user reads the keypad by bringing each row up to logic: HIGH, ...

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 ...

What can you do with ten buttons and ten lights? A lot. [Andrew] and [Nathan] found a collection of Hale Research keypads being thrown out, and decided to host the Keypad Contest. The goal of 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 ...

A version of thie article appeared in the February 2012 issue of Test & Measurement World. See the PDF. Many industrial systems use the 4–20-mA loop to transmit measurements from sensors to displays, ...

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 ...