Sunday, February 20, 2011

555 timer could reduce number of pins in keypad interfacing

A 4x3 matrix keypad requires 7 I/O pins of microcontroller for interfacing. But you could reduce the required number of connections to two by using a 555 timer IC. If you want to know how, visit Embedded Lab's new post "2-Wire Keypad Interfacing using 555 Timer".


1 comment:

  1. WOW, Nice One. Reducing pins by spending 10 rs is worth.

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Microcontroller-based Embedded Systems Design