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7 of 7 articles

Interfacing Keypad

Matrix keypad scanning.

Mohith N
Updated: 19 March 2026
12 min read
#Embedded Systems

Keypad Interfacing Quiz

Test your understanding of matrix keypad scanning techniques.

Question 1 of 3

Q1.A 4x4 matrix keypad has 16 keys but requires only 8 GPIO lines. During column scanning, if column 2 is driven LOW and the microcontroller reads row 3 as LOW, which key is pressed (assuming rows and columns are 0-indexed)?

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