Maker Pro
Maker Pro

keypad

garlitos

Jun 7, 2013
3
Joined
Jun 7, 2013
Messages
3
i have this keypad design and it works fine. i need to know why there is the 1K resistors. any help?
 

Attachments

  • Keypad.JPG
    Keypad.JPG
    33.6 KB · Views: 143

davenn

Moderator
Sep 5, 2009
14,254
Joined
Sep 5, 2009
Messages
14,254
they are either pull up or pull down resistors ( depending on if they are going to the +V rail or the 0V rail)
The chip that scans the keyboard keys will see wither +V or 0V till the key is press when the opposite polarity is read

Dave
 
Top