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PmodLS1™ Reference Manual
Revised May 26, 2016
This manual applies to the PmodLS1 rev. B
Copyright Digilent, Inc. All rights reserved.
Other product and company names mentioned may be trademarks of their respective owners.
Overview
The Digilent PmodLS1 allows users to receive signals from multiple optical sensors, such as the popular
combination of an IR LED with an IR sensor used in line-following robots.
1 Functional Description
The PmodLS1 is designed to be used with up to four sensors containing an infrared LED and an infrared-sensitive
photo-transistor, such as the IR Proximity Sensor available from Digilent. When using Digilent's sensors, refer to
the print on the board indicating the wire color for the correct orientation of the wire. If third-party sensors are
used, refer to the board schematic available at www.digilentinc.com for the proper connection of the LED and
photo-transistor.
The module uses analog comparators to determine when the infrared detectors have sensed more infrared light
than the threshold limit. The sensitivity of the sensors can be adjusted by adjusting the onboard potentiometer.
2 Interfacing with the Pmod
The PmodLS1 communicates with the host board via the GPIO protocol. By the Pmod design, each of the outputs
will only send a logic 1 value when its sensor is picking up more optical light than the threshold limit. When the
Infrared light detector with on-board
sensitivity adjustment
Interface with up to four reflective or
transmissive photo detectors
Works with Digilent IR Proximity Sensor
Small PCB size for flexible designs 1.4“ ×
0.8” (3.6 cm × 2.0 cm)
6-pin Pmod connector with GPIO interface
Follows Digilent Pmod Interface
Specification Type 1
