Pololu Digital Distance Sensor, 5cm

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Pololu item #: 4050
Brand: Pololu
Status: Active 
RoHS 3 compliant


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.

Note: A newer version of this sensor is now available.

Alternatives available with variations in these parameter(s): maximum range connector Select variant…

Pictures

Pololu Digital Distance Sensor, 5cm.

Pololu Digital Distance Sensor, 5cm.

Pololu Digital Distance Sensor (irs16a), back view.

Pololu Digital Distance Sensor (irs16a), back view.

Pololu Digital Distance Sensor (irs16a), back view with dimensions.

Original (irs16a) version of the Pololu Digital Distance Sensor, top view with labeled pinout.

Output signal behavior of the Pololu Digital Distance Sensor, 5cm (irs16a).

Original (irs16a) short-range Pololu Digital Distance Sensors.

Comparison of the different Pololu Digital Distance Sensor versions.

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).

Standard packaging for the Pololu Digital Distance Sensor, 5cm.

Comparison of a Pololu Carrier with Sharp GP2Y0D8x Digital Distance Sensor and a Pololu Digital Distance Sensor.

Comparison of a Pololu Carrier with Sharp GP2Y0D8x Digital Distance Sensor and a Pololu Digital Distance Sensor.

Comparison of a Pololu Carrier with Sharp GP2Y0D8x Digital Distance Sensor and a Pololu Digital Distance Sensor.




Overview

Pololu Digital Distance Sensor, 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 about 5 mm of the sensor face.

This sensor has 0.1″-pitch through holes that are compatible with 0.1″ headers. A similar alternative is 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:

Specifications

Using the sensor

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.

Pololu Digital Distance Sensor, 5cm.

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 original (irs16a) 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 original (irs16a) 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.)

Original (irs16a) short-range version jumper settings
Item # Description Maximum
range(1)
Hysteresis Resolution Minimum
update
rate
Jumper
settings
(4321)
#4050 Digital output, 5cm 5 cm 16 mm - 145 Hz 0000
Digital output, 5cm (high sensitivity) 5 cm 16 mm - 65 Hz 0001
#4052 Digital output, 10cm 10 cm 20 mm - 115 Hz 0010
Digital output, 10cm (high sensitivity) 10 cm 20 mm - 30 Hz 0011
#4054 Digital output, 15cm 15 cm 24 mm - 95 Hz 0100
Digital output, 15cm (high sensitivity) 15 cm 24 mm - 15 Hz 0101
Digital output, 20cm 20 cm 28 mm - 70 Hz 0110
Digital output, 20cm (high sensitivity) 20 cm 28 mm - 15 Hz 0111
Digital output, 30cm 30 cm 36 mm - 37 Hz 1000
Digital output, 30cm (high sensitivity) 30 cm 36 mm - 15 Hz 1001
Digital output, any detect ~50 cm - - 50 Hz 1010
Digital output, any detect ~100 cm - - 15 Hz 1011
Pulse width output, 15cm max ~15 cm - 1 mm
(= 4 µs)
145 Hz
(190 Hz max)
1100
Pulse width output, 35cm max ~35 cm - 2 mm
(= 4 µs)
95 Hz
(165 Hz max)
1101
#4064 Pulse width output, 50cm max ~50 cm - 3 mm
(= 4 µs)
50 Hz
(110 Hz max)
1110
Note 1: Effective range depends on object reflectivity and ambient lighting conditions.

Item numbers in this table indicate versions that we offer for sale as standard products, but we can manufacture the other versions on demand (or even make sensors with custom firmware for you). If you are interested in customization, please contact us.

The Pololu Digital Distance Sensor family

We have several versions of Pololu Digital Distance Sensors with different ranges, operating modes, and connector options:

High/low digital output
(indicates detection within specified range; does not provide distance measurement)
Sensor
type
Item # Maximum
range(1)
Minimum
range
Hysteresis Minimum
update
rate
Price
no
connector
side-entry
connector
original
short‑range
(irs16a)
#4050 5 cm < 5 mm 16 mm 145 Hz $19.95
#4052 10 cm 20 mm 115 Hz
#4054 15 cm 24 mm 95 Hz
v2
short-range
#5550 #5460 5 cm < 1 mm 35 mm 142 Hz $19.95
#5552 #5462 10 cm
#5554 #5464 15 cm
long-range #4066 #5480 25 cm < 1 mm 50 mm 100 Hz $24.95
#4067 #5481 50 cm 100 Hz
#4069 #5483 100 cm 100 Hz
#4077 #5491 200 cm 30 Hz
Pulse width output
(provides distance measurement encoded as the width of a digital pulse)
Sensor
type
Item # Maximum
range(1)
Minimum
range(2)
Resolution Minimum
update
rate
Price
no
connector
side-entry
connector
original
short-range
#4064 ~50 cm 1 cm 3 mm
(= 4 µs)
50 Hz $19.95
v2
short-range
#5562 #5472 ~50 cm < 0.1 cm 1 mm
(= 1.33 µs)
142 Hz $19.95
long-range #4071 #5485 ~130 cm 4 cm 1 mm
(= 0.5 µs)
100 Hz $24.95
#4079 #5493 ~300 cm 4 cm 2 mm
(= 0.5 µs)
30 Hz
Note 1: Effective range depends on object reflectivity and ambient lighting conditions.
Note 2: Objects closer than the minimum distance can still be detected, but the measured distance might be inaccurate. The minimum detection distance is < 5 mm for the original (irs16a) short-range sensors and < 1 mm for everything else.

The Pololu Digital Distance Sensor family includes several different sensor types. The jumper options are different for the different sensor types, so it is important to be able to identify which type you have if you want to change the jumper settings. The following diagram shows some key visual differences among the different sensor types:

Comparison of the different Pololu Digital Distance Sensor versions.

Within each sensor type, there are digital output versions that just report if an object is within their detection range and pulse width output versions that report the measured distance by encoding it as the width of a repeating digital pulse, similar to hobby servo control signals. The graphs below show some examples of the different possible output signals from the different Pololu Digital Distance Sensor versions.

Comparison to Sharp/Socle Digital Distance Sensors

These Pololu Digital Distance Sensors have the same general form factor and pinout as our carrier boards for the Sharp/Socle GP2Y0D8x digital distance sensors (the versions with through-holes have the same length and width while the versions with JST SH-style connectors are 0.05″ longer). They are available in the same 5 cm, 10 cm, and 15 cm ranges as the Sharp/Socle sensors, in addition to longer ranges of up to several meters. This means they can be used as replacements for these older modules, which are based on sensors that are no longer in production, and the longer-range versions can serve as upgrades that provide enhanced detection and measurement capabilities. The sensors on these newer units are much thinner than the Sharp modules, so the zero-range point is approximately 7 mm closer to the PCB, and the beam angle of the newer units is wider. The pictures below show side-by-side comparisons of the two:

Firmware version history

The Pololu Digital Distance Sensors use a small integrated microcontroller to operate the distance sensor, drive the OUT pin, and control the on-board LED. The different sensor types have different firmware versions:

If you have an affected irs16a unit with firmware version 2 and you would like a replacement, please contact us.

Determining the firmware version

When you apply power to the board or make it reset by any other means, the microcontroller transmits a signal with the firmware version on the via marked in the picture below.

The via that outputs firmware version information at startup on a Pololu Digital Distance Sensor.

To see the signal, you can probe the via with an oscilloscope. Configure it to trigger on a rising edge with a threshold around 1 V to 2 V and to capture data for at least 1 ms after the trigger. Then apply power to the distance sensor.

Each bit in the signal is transmitted as a high pulse. A 1 µs pulse indicates a 0, while a 3 µs pulse indicates a 1. The first two bits are 1 and 0, and they are followed by an 8-bit firmware version number, most significant bit first. The signal from a board running firmware version 4 looks like this:

Version signal from a Pololu Digital Distance Sensor running firmware version 4 (100 in binary).

Dimensions

Size: 0.85″ × 0.35″ × 0.122″
Weight: 0.4 g

General specifications

Maximum range: 5 cm
Update rate: 145 Hz1
Minimum operating voltage: 3.0 V
Maximum operating voltage: 5.5 V
Connector: none (0.1″-pitch through-holes)
Supply current: 30 mA2
Output type: digital3

Identifying markings

PCB dev codes: irs16a
Other PCB markings: 0J13085

Notes:

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.

File downloads

Frequently-asked questions

No FAQs available.

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