1 / 10

Hexadecimal Keypad

Hexadecimal Keypad. Doug Butterworth Email: epor@psu.edu AIM: Epor55 Phone: 814.217.2466. Hardware Description Internal Organization The Circuit in Action Signal Bouncing. Hardware Description:. 16-Button Numeric Keypad Rugged black plastic

lala
Download Presentation

Hexadecimal Keypad

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Hexadecimal Keypad Doug Butterworth Email: epor@psu.edu AIM: Epor55 Phone: 814.217.2466 • Hardware Description • Internal Organization • The Circuit in Action • Signal Bouncing

  2. Hardware Description: 16-Button Numeric Keypad • Rugged black plastic • 4 x 4 Matrix Type • 8-position solder pad • Contact rating: 24VDC @ 20mA • Contact resistance: 200 Ohms max. • Life test: 1,000,000 life cycles per key • Size: 3.0"L x 2.8"W x 0.6"H • $7.95 from Links: Product Page Technical Documentation(pretty under whelming)

  3. Internal Organization Output organization Output pin #Symbol Pin 1 Row 2 Pin 2 Row 3 Pin 3 Col 1 Pin 4 Row 4 Pin 5 Col 2 Pin 6 Col 3 Pin 7 Col 4 Pin 8 Row 1 When a button is pushed, the associated row and column pin for that button are connected together.

  4. Circuit Diagram Row 1 1 2 3 A

  5. Hex Keypad: The Movie!

  6. Uses • Wired into a keypad encoder. (presentation 19 with Anthony Dotterer) • Xilinx • Use your imagination…

  7. Signal Bouncing Background Theory: • Nearly all mechanical switches generate some bounce. • After switched, they actually open and close several times before settling down to their new position. • Can Last as little as a fraction of a millisecond to as long as 50 ms. • Only very high quality switches generate little or no bounce.

  8. Signal Bouncing (Simulated by touching a wire to a alligator clip)

  9. Signal Bouncing On the Keypad (Wow!)

  10. How to prevent: • Use an RC network to slow either the rising or falling edge of the event. • Buy a really good switch!

More Related