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 ...

A PIC16877 microcontroller is used to connect in particular to a 4X5 keypad which can also be connected with logic and analogue circuits. A PIC16877 microcontroller is used to connect in particular to ...

[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 ...

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 ...