4x4 Keypad Reader DEMO

Warning message

The Propeller Object Exchange system is decommissioned and replaced with a GitHub repository to house the same existing and future Propeller objects. As of 12/5/2019, this site is read-only. You can continue to browse and download objects from here for a limited time; however, please begin using the Parallax Propeller repository for future reference.
  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0
Request group membership
By: created: 2015-01-22 | updated: 2015-01-22

DEMO displays on a VGA monitor.

Uses a capacitive pin approach to read a 4x4 keypad.

  • PRO's - No resistors, capacitors, or external IC's required.
  • CON's - requires 8 I/O's

The keypad decoding routine only requires two subroutines and returns the entire 4x4 keypad matrix into a single WORD variable indicating which buttons are pressed. Multiple button presses are allowed with the understanding that “BOX” entries can be confused. An example of a BOX entry... 1,2,4,5 or 1,4,3,6 or 4,6,*,# etc. where any 3 of the 4 buttons pressed will evaluate the non pressed button as being pressed, even when they are not. There is no danger of any physical or electrical damage, that's just the way this sensing method happens to work.

Original File Upload
AttachmentSize
Package icon 4x4_keypad_Reader_DEMO.zip18.88 KB