Pololu Digital Distance Sensor with Side-Entry Connector – 25cm

This small lidar-based distance sensor from Pololu detects the presence of objects within 25 cm (10). It has a single digital output that drives low when an object is being detected; otherwise, it is high. It works over an input voltage range of 3.0V to 5.5V and features a side-entry 3-pin JST SH-style connector that is compatible with our 3-pin JST SH-style cables.

As long as the sensor is enabled, it takes continuous distance measurements and uses a single digital output to indicate if it detects an object within its detection range. The output is driven low when the sensor detects an object; otherwise, the output is high.

Please note that this sensor will only tell you if there is an object within the detection range along its line of sight, not how far away it is. As shown in the diagram below, there is hysteresis at the maximum range threshold to help ensure a clean transition as objects cross the threshold. The sensor can detect objects to within about 1 mm of the sensor face.

Unlike simpler optical sensors that use the intensity of reflected light to detect objects, this sensor uses a short-range lidar module to precisely measure how long it takes for emitted pulses of infrared, eye-safe laser light to reach the nearest object and be reflected back. This allows the sensor performance to be largely independent of object reflectivity and ambient lighting conditions (though the range can be reduced for extremely low-reflectance objects).

Some example applications include:

• Break-beam sensor or photogate alternative
• Non-contact bumper or obstacle detector for a robot
• Non-contact interface element for activating a device or process
• A counter or timer of objects as they pass by

Using the sensor

Important note: This product might ship with a protective liner covering the sensor IC. The liner must be removed for proper sensing performance:

Three connections are necessary to use this module: VIN, GND, and OUT. These pins are accessible through the boards 3-pin male JST SH-style connector, which is compatible with our 3-pin JST SH-style cables. When used with our cables, the black wire connects to GND (pin 1), the red wire connects to VIN (pin 2), and the white wire connects to OUT (pin 3).

The VIN pin should be connected to a 3 V to 5.5 V source, and GND should be connected to 0 volts. The OUT pin drives low (0 V) when an object is being detected and it drives high (to the VIN level) when an object is not being detected. It is weakly pulled high when the sensor is disabled or waiting for its first reading to complete after power-up. A red LED on the back side of the board also lights whenever an object is detected.

The board has an optional ENABLE pin that can be driven low to put it into a low-power state that consumes approximately 0.4 mA. This pin can be accessed through a via or its neighbouring surface-mount pad on the back side labelled EN on the silkscreen. The ENABLE pin is pulled up to VIN, enabling the sensor by default.

The board has one mounting hole intended for use with #2 or M2 screws.

Jumper settings for long-range versions

This board features four surface-mount configuration jumpers that determine its operation mode. Different versions of the Pololu Digital Distance Sensors ship with the appropriate jumpers pre-populated with 0 resistors. These resistors can be desoldered from the populated spots, or solder bridges can be added across the unpopulated spots to convert one sensor version into another.

This sensor can be converted into any other long-range version, as listed in the following table:

Note 1: Effective range depends on object reflectivity and ambient lighting conditions.

Specifications

1. Minimum.
2. Typical average current draw when enabled; disabling via the EN pin reduces it to around 0.4 mA.
3. Low when detecting an object, high otherwise.

Resources

• Dimensions
• 3D Model (STEP)
• Drill Guide

Package Contents

• 1x Pololu Digital Distance Sensor with Side-Entry Connector – 25cm