410-195

1300 Henley Court Pullman, WA 99163 509.334.6306 www.digilentinc.com PmodKYPD™ Reference Manual Revised April 8, 2016 This manual applies to the PmodKYPD rev. B Overview The Digilent PmodKYPD is a 16 button keypad, providing users with immense configurability. Features include:        16 momentary push-buttons Can detect simultaneous button presses Isolated rows and columns Small PCB size for flexible designs 3.4“ × 2.7” (8.6 cm × 6.9 cm) 12-pin Pmod port with GPIO interface Follows Digilent Pmod Interface Specification Type 1 Library and example code available in resource center The PmodKYPD. 1 Functional Description The PmodKYPD utilizes 4 rows and columns to create an array of 16 momentary pushbuttons. By driving the column lines to a logic level low voltage one at a time, users may read the corresponding logic level voltage on each of the rows to determine which button, if any, is currently being pressed. Simultaneous button presses can also be recorded, although it is still required to step through each row and column separately in order to ensure that the pressed buttons do not interfere with each measurement. 2 Interfacing with the Pmod The PmodKYPD communicates with the host board via the GPIO protocol. Each button is placed within a simple voltage divider circuit. When a button is not pressed, a large pull-up resistor maintains a logic level high voltage on each of the row pins. When a column pin is driven to a logic level low voltage and a corresponding DOC#: 502-195 Copyright Digilent, Inc. All rights reserved. Other product and company names mentioned may be trademarks of their respective owners. Page 1 of 2 PmodKYPD™ Reference Manual button is pressed, completing the voltage divider circuit, the row pin will then read a logic level low voltage instead. Pin 1 2 3 4 5 6 Signal COL4 COL3 COL2 COL1 GND VCC Header J1 Description Pin Column 4 7 Column 3 8 Column 2 9 Column 1 10 Power Supply Ground 11 Power Supply (3.3V/5V) 12 Signal ROW4 ROW3 ROW2 ROW1 GND VCC Description Row 4 Row 3 Row 2 Row 1 Power Supply Ground Power Supply (3.3V/5V) Table 1. Pinout description table. Any external power applied to the PmodKYPD must be within a voltage that your system board can handle; It is recommended that Pmod is operated at 3.3V. 3 Physical Dimensions The pins on the pin header are spaced 100 mil apart. The PCB is 3.4 inches long on the sides parallel to the pins on the pin header and 2.7 inches long on the sides perpendicular to the pin header. Copyright Digilent, Inc. All rights reserved. Other product and company names mentioned may be trademarks of their respective owners. Page 2 of 2