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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".


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  1. FaizMay 21, 2012 at 9:57 AM

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

    ReplyDelete

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