Pmod 8LD Reference Manual

The Digilent Pmod 8LD (Revision B) has eight high-brightness LEDs that are driven by logic-level transistors so that each LED can be individually illuminated from a logic high signal.

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  • Eight high brightness green LEDs
  • Uses BJTs for low power logic level control
  • 2×6-pin Pmod port with GPIO interface

Functional Description

The Pmod 8LD utilizes individual transistors so that each LED can be turned on or off independently. In order to activate an LED, the associated pin on the pin header must receive about 1mA of current.

Interfacing with the Pmod

The Pmod 8LD communicates with the host board via GPIO pins. Correspondingly, to turn a particular LED on, the pin must be driven to a logic high state and driven to a logic low state to turn a LED off. With the parallel arrangement of these LEDs it is possible to turn on (or off) multiple LEDs simultaneously.

A pin description and diagram are provided below.

Pinout Description Table

Header J1
Pin Signal Description
1 LD0 LED 0
2 LD1 LED 1
3 LD2 LED 2
4 LD3 LED 3
5 GND Power Supply Ground
6 VCC Power Supply (3.3V)
7 LD4 LED 4
8 LD5 LED 5
9 LD6 LED 6
10 LD7 LED 7
11 GND Power Supply Ground
12 VCC Power Supply (3.3V)

Physical Dimensions

The pins on the pin header are spaced 100 mil apart. The PCB is 1.1 inches long on the sides parallel to the pins on the pin header and 0.8 inches long on the sides perpendicular to the pin header.

Additional Information

The schematics of the Pmod 8LD are available here.

Example code demonstrating how to get information from the Pmod 8LD can be found here.

If you have any questions or comments about the Pmod 8LD, feel free to post them under the appropriate section (“Add-on Boards”) of the Digilent Forum.