Owner's manual

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Revision: October 6, 2011
Note: This document applies to REV B of the board.
1300 NE Henley Court, Suite 3
Pullman, WA 99163
[phone] Voice | [phone] Fax
Doc: 502-195 page 1 of 1
Copyright Digilent, Inc. All rights reserved. Other product and company names mentioned may be trademarks of their respective owners.
Overview
The PmodKYPD is an array of buttons used for
input.
Features include:
• 16 labelled keys (0-F)
• 12-pin header
Functional Description
The PmodKYPD uses a standard 12-pin Pmod
header that indicates which row and which
column has been pressed in the array of
buttons.
Connector J1
–
Column/Row Indicators
Pin
Signal
Description
1 COL4 Column 4
2 COL3 Column 3
3 COL2 Column 2
4 COL1 Column 1
5 GND Power Supply Ground
6 VCC Power Supply (3.3V)
7 ROW4 Row 4
8 ROW3 Row 3
9 ROW2 Row 2
10 ROW1 Row 1
11 GND Power Supply Ground
12 VCC Power Supply (3.3V)
Device Usage
The PmodKYPD is set up as a matrix in which
each row of buttons from left to right are tied to
a row pin, and each column from top to bottom
is tied to a column pin. This gives the user four
row pins and four column pins to address the
button push.
To read a button’s state, the column pin in
which the button resides must be pulled low.
This enables all of the buttons in that column.
When a button in that column is pushed, the
corresponding row pin will read logic low.
All of the buttons can be read by walking a
logic 0 through each column pin (keeping the
other pins at logic high) and reading the row
pins. This will read the state of each button.