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1300 Henley Court Pullman, WA 99163 509.334.6306 www.digilentinc.com PmodSSD™ Reference Manual Revised May 24, 2016 This manual applies to the PmodSSD rev. A Overview The PmodSSD is a two-digit seven-segment display. Users can toggle through GPIO signals which digit is currently on at a rate of 50Hz or greater to achieve persistence-of-vision to give the effect of both digits being lit up simultaneously. Features include:       Two-digit high brightness seven-segment display Easily view a counter or timer Common Cathode configuration Small PCB size for flexible designs 1.0“ × 1.7” (2.5 cm × 4.3 cm) Two 6-pin Pmod connectors with GPIO interfaces Follows Digilent Pmod Interface Specification Type 1 The PmodSSD. 1 Functional Description The PmodSSD utilizes a common cathode configuration to display a variety of LED segment combinations. The ten segment combinations corresponding to digits 0 - 9 are generally the most useful, although other custom combinations can also be created. 2 Interfacing with the Pmod The PmodSSD communicates with the host board via the GPIO protocol. A logic level high signal on a particular anode will light up that respective segment on whichever digit is currently enabled. Users are able to select a particular digit by driving the Digit Selection pin (C) to a logic high or low voltage. DOC#: 502-126 Copyright Digilent, Inc. All rights reserved. Other product and company names mentioned may be trademarks of their respective owners. Page 1 of 2 PmodSSD™ Reference Manual Because only one digit can be lit at a particular time, users that want to use both digits to display a particular value will need to alternately light up the two digits at least every 20 milliseconds (50 Hz). This will correlate to each digit being lit up for 10 milliseconds each before the other segment needs to be “turned on”. Higher refresh rates can be achieved by alternating which digit is currently powered at shorter time intervals. Pin 1 2 3 4 5 6 Signal AA AB AC AD GND VCC Header J1 Description Segment A Segment B Segment C Segment D Power Supply Ground Positive Power Supply Pin 1 2 3 4 5 6 Signal AE AF AG C GND VCC Header J2 Description Segment E Segment F Segment G Digit Selection pin Power Supply Ground Positive Power Supply Table 1. Pinout description table. J1 Connector 560 P1 AA P2 AB P3 AC P4 AD GND J2 Connector Vcc P1 AE P2 AF P3 AG AA1 AB1 AC1 AD1 AE1 AF1 AG1 C1 AA2 AB2 AC2 AD2 AE2 AF2 AG2 C2 P4 C GND GND Vcc Vcc Figure 1. Seven-segment display connection diagram. Any external power applied to the PmodSSD must be within 2.7V and 5.25V; however, 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 1 inch long on the sides parallel to the pins on the pin header and 1.7 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