Pololu Digital Distance Sensor v2, 5cm

This small lidar-based distance sensor detects the presence of objects within 5 cm (2″). 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 3.0 V to 5.5 V, and the 0.1″ pin spacing makes it easy to use with standard solderless breadboards and 0.1″ perfboards.

Overview

Pololu Digital Distance Sensor v2, 5cm.

This compact sensor provides a simple way to detect the presence of objects up to 5 cm (2″) away. 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.

A camera with no IR filter shows the infrared light emitted by a Pololu Digital Distance Sensor (this light is eye-safe and not visible to the naked eye).

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 above, 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 less than 1 mm of the sensor face.

This sensor has 0.1″-pitch through holes that are compatible with 0.1″ headers. A functionally identical version is also available with a side-entry connector that works with our 3-pin JST SH-style cables.

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

Specifications

• Operating voltage: 3.0 V to 5.5 V
• Current consumption: 30 mA (typical) when enabled, 0.4 mA when disabled
• Maximum range: 5 cm (2″)
• Minimum range: < 1 mm
• Minimum update rate: 142 Hz (7 ms period)
• Field of view (FOV): 10° typical; can vary with object reflectance and ambient conditions
• Emitter: eye-safe, 940 nm invisible Class 1 VCSEL (vertical cavity surface-emitting laser)
• Output type: digital signal (low when detecting an object, high otherwise)
• Dimensions: 0.85″ × 0.35″ × 0.122″ (21.6 × 8.9 × 3.1 mm); see the dimension diagram (277k pdf) for more information
• Weight: 0.015 oz (0.4 g)

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 a row of 0.1″-pitch through holes, which work with standard 0.1″ (2.54 mm) male headers and 0.1″ female headers (available separately). 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 neighboring surface-mount pad on the back side labeled “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 v2 short-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 Ω 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 v2 short-range version as listed in the following table. (For more information about how the different output types work, see the product pages for representative versions.)