[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 ...

Join Hackaday Editor-in-Chief Elliot Williams and Managing Editor Tom Nardi as they bring you up to speed on the best stories and projects from the week. There’s some pretty unfortunate news for the ...

Whenever I use the 555 timer, it seems that the output polarity is invariably incorrect, and the way the 555 functions, it normally cannot generate a duty cycle of less than 50% — 90% yes, 10% NO!

Applications of commercially available integrated timers, including the NE/SE555, are fairly limited when used in their monostable mode. This is due to their inability to function with all types of ...