# Pololu Digital Distance Sensor 15cm

**Type:** Product page · **SKU:** POLOLU-4054 · **Brand:** [Pololu](https://core-electronics.com.au/brands/pololu-australia)
**Page:** https://core-electronics.com.au/pololu-digital-distance-sensor-15cm.html ([markdown](https://core-electronics.com.au/pololu-digital-distance-sensor-15cm.html.md))

This small lidar-based distance sensor detects the presence objects within 15 cm (6"). It has a single digital output that drives low when an object is ...

## Pricing

- **Price:** $30.10 (inc GST) — $27.36 AUD, exc GST
- **Quantity discounts:** 10+ $26.27 (exc GST) · 25+ $25.45 (exc GST)

## Availability & dispatch

- Available with a lead time — expect dispatch between Aug 31 and Sep 02.

## Description

This compact sensor is a great way to quickly detect the presence of nearby objects. 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.

| [![](https://core-electronics.com.au/attachments/localcontent/0J11153_195728136ed.jpg)](https://core-electronics.com.au/attachments/localcontent/0J11153_165206afe34.png) |
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| [![](https://core-electronics.com.au/attachments/localcontent/0J11161_1848055f629.jpg)](https://core-electronics.com.au/attachments/localcontent/0J11161_37599f1ec4d.jpg) |
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| [**\#4050: Digital output, 5cm**](https://core-electronics.com.au/pololu-digital-distance-sensor-5cm.html) | 5 cm | < 5 mm | 145 Hz | 0000 | irs16a |
| [**\#4052: Digital output, 10cm**](https://core-electronics.com.au/pololu-digital-distance-sensor-10cm.html) | 10 cm | < 5 mm | 115 Hz | 0010 |
| [**\#4054: Digital output, 15cm**](https://core-electronics.com.au/pololu-digital-distance-sensor-15cm.html) | 15 cm | < 5 mm | 95 Hz | 0100 |
| [**\#4066: Digital output, 25cm**](https://core-electronics.com.au/pololu-digital-distance-sensor-25cm.html) | 25 cm | < 1 mm | 100 Hz | 0000 | irs17a |
| [**\#4067: Digital output, 50cm**](https://core-electronics.com.au/pololu-digital-distance-sensor-50cm.html) | 50 cm | < 1 mm | 100 Hz | 0001 |
| [**\#4069: Digital output, 100cm**](https://core-electronics.com.au/pololu-digital-distance-sensor-100cm.html) | 100 cm | < 1 mm | 100 Hz | 0011 |
| [**\#4077: Digital output, 200cm**](https://core-electronics.com.au/pololu-digital-distance-sensor-200cm.html) | 200 cm | < 1 mm | 30 Hz | 1011 |

| **Pulse width output** (provides distance measurement) |
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| [**\#4064: Pulse width output, 50cm max**](https://core-electronics.com.au/pololu-distance-sensor-with-pulse-width-output-50cm-max.html) | ~50 cm | 1 cm | 3 mm | 50 Hz | 1110 | irs16a |
| [**\#4071: Pulse width output, 130cm max**](https://core-electronics.com.au/pololu-distance-sensor-with-pulse-width-output-130cm-max.html) | ~130 cm | 4 cm | 1 mm | 100 Hz | 0101 | irs17a |
| [**\#4079: Pulse width output, 300cm max**](https://core-electronics.com.au/pololu-distance-sensor-with-pulse-width-output-300cm-max.html) | ~300 cm | 4 cm | 2 mm | 30 Hz | 1101 |

**1** Effective range depends on object reflectivity and ambient lighting conditions.
**2** Objects closer than the minimum distance can still be detected, but the measured distance might be inaccurate. The minimum detection range is < 5 mm for irs16a boards and < 1 mm for irs17a boards.

These are the output graphs for the digital output versions that just report if an object is in their detection range:

| \| [![](https://core-electronics.com.au/attachments/localcontent/0J11151_14459e94304.jpg)](https://core-electronics.com.au/attachments/localcontent/0J11151_161893d4a2f.png) \| \|---\| | \| [![](https://core-electronics.com.au/attachments/localcontent/0J11152_1492650dce1.jpg)](https://core-electronics.com.au/attachments/localcontent/0J11152_161712441a0.png) \| \|---\|---\| | \| [![](https://core-electronics.com.au/attachments/localcontent/0J11153_15147671872.jpg)](https://core-electronics.com.au/attachments/localcontent/0J11153_165206afe34.png) \| \|---\|---\| |
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| \| [![](https://core-electronics.com.au/attachments/localcontent/0J11270_15345089aa6.jpg)](https://core-electronics.com.au/attachments/localcontent/0J11270_1733253634e.png) \| | \| [![](https://core-electronics.com.au/attachments/localcontent/0J11271_154837e1216.jpg)](https://core-electronics.com.au/attachments/localcontent/0J11271_1670865d2ba.png) \| \|---\|---\| | \| [![](https://core-electronics.com.au/attachments/localcontent/0J11272_15637700695.jpg)](https://core-electronics.com.au/attachments/localcontent/0J11272_16713404988.png) \| \|---\|---\| |
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|  | \| [![](https://core-electronics.com.au/attachments/localcontent/0J11273_162551934d5.jpg)](https://core-electronics.com.au/attachments/localcontent/0J11273_1707036dc59.png) \| |  |
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The output graph is a bit different for the versions that use a pulse width to encode the measured distance. The output for these versions is similar to hobby servo control signals and is shown below as a function of time:

| [![](https://core-electronics.com.au/attachments/localcontent/0J11154_155369da88d.jpg)](https://core-electronics.com.au/attachments/localcontent/0J11154_1138444602d.png) |
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**Comparison to Sharp Digital Distance Sensors**

These Pololu Digital Distance Sensors have the same form factor and pinout as Pololu's [carrier boards](https://core-electronics.com.au/pololu-carrier-with-sharp-gp2y0d805z0f-digital-distance-sensor-5cm.html) for the Sharp/Socle [GP2Y0D8x](https://core-electronics.com.au/sharp-gp2y0d805z0f-digital-distance-sensor-5cm.html) digital distance sensors. They are available in the same 5 cm, 10 cm, and 15 cm ranges, 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 from Sharp/Socle 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:

| \| [![](https://core-electronics.com.au/attachments/localcontent/0J11148_20138131664.jpg)](https://core-electronics.com.au/attachments/localcontent/0J11148_26559a01264.jpg) \| \|---\| | \| [![](https://core-electronics.com.au/attachments/localcontent/0J11149_18610c7ab52.jpg)](https://core-electronics.com.au/attachments/localcontent/0J11149_7696343d025.jpg) \| \|---\|---\| | \| [![](https://core-electronics.com.au/attachments/localcontent/0J11150_8100c926fc.jpg)](https://core-electronics.com.au/attachments/localcontent/0J11150_4387980789c.jpg) \| \|---\|---\| |
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**Firmware version history**

The Pololu Digital Distance Sensors (irs16a and irs17a) use a small integrated microcontroller to operate the distance sensor, drive the OUT pin, and control the on-board LED. There have been several different versions of the firmware for this microcontroller:

- **Version 2:** This is the initial-release version of the irs16a firmware.
- **Version 3:** This is the initial-release version of the irs17a firmware; it is not used on the irs16a boards.
- **Version 4:** This update for the irs16a boards fixes a bug in the version 2 firmware that could cause some units to erroneously have a 25 cm offset in their readings (i.e. to incorrectly measure distances as approximately 25 cm farther than reality). Only a small percentage of boards with version 2 firmware were susceptible, and the problem only occurred when those susceptible units were operating in modes with a maximum sensing range of 20 cm or more. **All irs16a units shipped from Pololu on or after January 30th, 2024 have firmware version 4.** This firmware is not used on the irs17a boards.

If you have an affected irs16a unit with firmware version 2 and you would like a replacement, please [contact us](https://core-electronics.com.au/contact).

**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.

| [![](https://core-electronics.com.au/attachments/localcontent/0J12376_269296683d1.jpg)](https://core-electronics.com.au/attachments/localcontent/0J12376_12313f9d0de.jpg) |
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| 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:

| [![](https://core-electronics.com.au/attachments/localcontent/0J12375_52151534686.jpg)](https://core-electronics.com.au/attachments/localcontent/0J12375_182957de159.jpg) |
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| Version signal from a Pololu Digital Distance Sensor running firmware version 4 (100 in binary). |

**People often buy this product together with:**

| [![Pololu Digital Distance Sensor 5cm](https://core-electronics.com.au/attachments/localcontent/0J11132_3690d3292e.jpg)](https://core-electronics.com.au/pololu-digital-distance-sensor-5cm.html) | [Pololu Digital Distance Sensor 5cm](https://core-electronics.com.au/pololu-digital-distance-sensor-5cm.html) |
|---|---|

| [![Pololu Digital Distance Sensor 10cm](https://core-electronics.com.au/attachments/localcontent/0J11133_3711e1d048.jpg)](https://core-electronics.com.au/pololu-digital-distance-sensor-10cm.html) | [Pololu Digital Distance Sensor 10cm](https://core-electronics.com.au/pololu-digital-distance-sensor-10cm.html) |
|---|---|

| [![Pololu Distance Sensor with Pulse Width Output, 50cm Max](https://core-electronics.com.au/attachments/localcontent/0J11135_3779d30377.jpg)](https://core-electronics.com.au/pololu-distance-sensor-with-pulse-width-output-50cm-max.html) | [Pololu Distance Sensor with Pulse Width Output, 50cm Max](https://core-electronics.com.au/pololu-distance-sensor-with-pulse-width-output-50cm-max.html) |
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**Dimensions**

 | Size: | 0.85" × 0.35" × 0.122" |
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| Weight: | 0.4 g |

**General specifications**

 | Maximum range: | 15 cm |
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| Sampling rate: | 95 Hz[1](https://core-electronics.com.au/#note1) |
| Minimum operating voltage: | 3.0 V |
| Maximum operating voltage: | 5.5 V |
| Supply current: | 30 mA[2](https://core-electronics.com.au/#note2) |
| Output type: | digital[3](https://core-electronics.com.au/#note3) |

**Identifying markings**

 | PCB dev codes: | irs16a |
|---|---|
| Other PCB markings: | 0J13085 |

**Notes:**

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

- **[Dimension diagram of the Pololu Digital Distance Sensors (irs16a)](https://core-electronics.com.au/attachments/localcontent/pololu-digital-distance-sensor-dimensions-irs16a_19080c3b378.pdf) (191k pdf)**
- **3D model of the Pololu Digital Distance Sensors (irs16a) (4MB step)**
- **Drill guide for the Pololu Digital Distance Sensors (irs16a) (22k dxf)**
    
    This DXF drawing shows the locations of all of the board’s holes.

## Images

- [Product image 1](https://core-electronics.com.au/media/catalog/product/i/m/image_88.jpg)