Single-Channel QTR Reflectance Sensors

These reflectance sensors feature IR emitter/phototransistor modules that are well suited for applications that require detection of changes in reflectivity. This change in reflectivity can be due to a color change at a fixed distance, such as when sensing a black line on a white background, as well as due to a change in the distance to or presence of an object in front of the sensor. All of the products in this category are single-channel sensors that can be arranged in whatever spacing or configuration is needed; we also have arrays with different sensor counts and densities available.

Single-channel QTR sensors with dimmable emitters
2.9 V to 5.5 V; 30 mA max LED current(1)
Sensor
type
Max board
current(2)
Optimal
range
Max
range
Board size Connector Output
type
Name 1-piece
price
QTR 32 mA 5 mm 30 mm 5.0 × 20.0 × 2.5 mm analog QTR-HD-01A $3.25
RC (digital) QTR-HD-01RC $3.25
7.5 × 20.0 × 2.5 mm analog QTR-MD-01A $2.75
RC (digital) QTR-MD-01RC $2.75
8.1 × 15.2 × 5.5 mm side-entry
JST SH-type
analog QTR-MD-01A-S $3.95
RC (digital) QTR-MD-01RC-S $3.95
QTRX 5 mA 10 mm 30 mm 5.0 × 20.0 × 3.0 mm analog QTRX-HD-01A $3.75
RC (digital) QTRX-HD-01RC $3.75
7.5 × 20.0 × 3.0 mm analog QTRX-MD-01A $3.25
RC (digital) QTRX-MD-01RC $3.25
8.1 × 15.2 × 6.0 mm side-entry
JST SH-type
analog QTRX-MD-01A-S $4.29
RC (digital) QTRX-MD-01RC-S $4.29
QTRXL 32 mA 20 mm 80 mm 5.0 × 20.0 × 3.0 mm analog QTRXL-HD-01A $3.75
RC (digital) QTRXL-HD-01RC $3.75
7.5 × 20.0 × 3.0 mm analog QTRXL-MD-01A $3.37
RC (digital) QTRXL-MD-01RC $3.37
8.1 × 15.2 × 6.0 mm side-entry
JST SH-type
analog QTRXL-MD-01A-S $4.29
RC (digital) QTRXL-MD-01RC-S $4.29
1 Can be dynamically reduced to any of 32 available dimming levels.
2 With all LEDs on at max brightness setting.

Note: All of the boards with black PCBs are versions introduced in 2018 with integrated LED drivers that offer dimmable brightness control independent of the 2.9 V to 5.5 V supply voltage. The boards with red and green PCBs are our original QTR sensors without LED drivers, so the emitter brightness is a function of the supply voltage.

Products in category “Single-Channel QTR Reflectance Sensors”

Pololu item #: 4101
Brand: Pololu supply outlook
Status: Active and Preferred 
RoHS 3 compliant
Out of stock.
Quantity:
sensors size
(mm)
output max current optimal
range
LED board
1 5.0 × 20.0 RC (digital) 30 mA 32 mA 5 mm

This IR LED/phototransistor pair is great for precisely identifying changes in reflectance (like line detection). It operates from 2.9 V to 5.5 V and offers dimmable brightness control independent of the supply voltage. In general, the closer the object, the higher the contrast between light and dark readings, but high-reflectance objects are generally detectable out to around 30 mm. This version features a traditional-style QTR sensor without lenses.

Pololu item #: 4141
Brand: Pololu supply outlook
Status: Active and Preferred 
RoHS 3 compliant
Out of stock.
Quantity:
sensors size
(mm)
output max current optimal
range
LED board
1 7.5 × 20.0 RC (digital) 30 mA 32 mA 5 mm

This IR LED/phototransistor pair is great for precisely identifying changes in reflectance (like line detection). It operates from 2.9 V to 5.5 V and offers dimmable brightness control independent of the supply voltage. In general, the closer the object, the higher the contrast between light and dark readings, but high-reflectance objects are generally detectable out to around 30 mm. This version features a traditional-style QTR sensor without lenses.

Pololu item #: 4140
Brand: Pololu supply outlook
Status: Active and Preferred 
RoHS 3 compliant
Out of stock.
Quantity:
sensors size
(mm)
output max current optimal
range
connec­tor
LED board
1 8.1 × 15.2 RC (digital) 30 mA 32 mA 5 mm side-entry

This sensor uses an IR LED and a phototransistor to measure the light reflected from nearby surfaces. It operates from 2.9–5.5 V, with dimmable brightness control independent of the supply voltage. The optimal range is <5 mm, but it can detect high-reflectance objects out to around 30 mm. This version features a traditional-style QTR sensor without lenses and a connector that works with our 4-pin JST SH-style cables (compatible with SparkFun’s Qwiic and Adafruit’s STEMMA QT cables, but the interface is not I²C).

Pololu item #: 4201
Brand: Pololu supply outlook
Status: Active and Preferred 
RoHS 3 compliant
Out of stock.
Quantity:
sensors size
(mm)
output max current optimal
range
LED board
1 5.0 × 20.0 analog 30 mA 32 mA 5 mm

This IR LED/phototransistor pair is great for precisely identifying changes in reflectance (like line detection). It operates from 2.9 V to 5.5 V and offers dimmable brightness control independent of the supply voltage. In general, the closer the object, the higher the contrast between light and dark readings, but high-reflectance objects are generally detectable out to around 30 mm. This version features a traditional-style QTR sensor without lenses.

Pololu item #: 4241
Brand: Pololu supply outlook
Status: Active and Preferred 
RoHS 3 compliant
Out of stock.
Quantity:
sensors size
(mm)
output max current optimal
range
LED board
1 7.5 × 20.0 analog 30 mA 32 mA 5 mm

This IR LED/phototransistor pair is great for precisely identifying changes in reflectance (like line detection). It operates from 2.9 V to 5.5 V and offers dimmable brightness control independent of the supply voltage. In general, the closer the object, the higher the contrast between light and dark readings, but high-reflectance objects are generally detectable out to around 30 mm. This version features a traditional-style QTR sensor without lenses.

Pololu item #: 4240
Brand: Pololu supply outlook
Status: Active and Preferred 
RoHS 3 compliant
Out of stock.
Quantity:
sensors size
(mm)
output max current optimal
range
connec­tor
LED board
1 8.1 × 15.2 analog 30 mA 32 mA 5 mm side-entry

This sensor uses an IR LED and a phototransistor to measure the light reflected from nearby surfaces. It operates from 2.9–5.5 V, with dimmable brightness control independent of the supply voltage. The optimal range is <5 mm, but it can detect high-reflectance objects out to around 30 mm. This version features a traditional-style QTR sensor without lenses and a connector that works with our 4-pin JST SH-style cables (compatible with SparkFun’s Qwiic and Adafruit’s STEMMA QT cables, but the interface is not I²C).

Pololu item #: 4301
Brand: Pololu supply outlook
Status: Active and Preferred 
RoHS 3 compliant
Out of stock.
Quantity:
sensors size
(mm)
output max current optimal
range
LED board
1 5.0 × 20.0 RC (digital) 3.5 mA 5 mA 10 mm

This IR LED/phototransistor pair is great for precisely identifying changes in reflectance (like line detection). It operates from 2.9 V to 5.5 V and offers dimmable brightness control independent of the supply voltage. In general, the closer the object, the higher the contrast between light and dark readings, but high-reflectance objects are generally detectable out to around 30 mm. This version features a high-performance, low-current QTRX sensor with lenses.

Pololu item #: 4341
Brand: Pololu supply outlook
Status: Active and Preferred 
RoHS 3 compliant
Out of stock.
Quantity:
sensors size
(mm)
output max current optimal
range
LED board
1 7.5 × 20.0 RC (digital) 3.5 mA 5 mA 10 mm

This IR LED/phototransistor pair is great for precisely identifying changes in reflectance (like line detection). It operates from 2.9 V to 5.5 V and offers dimmable brightness control independent of the supply voltage. In general, the closer the object, the higher the contrast between light and dark readings, but high-reflectance objects are generally detectable out to around 30 mm. This version features a high-performance, low-current QTRX sensor with lenses.

Pololu item #: 4340
Brand: Pololu supply outlook
Status: Active and Preferred 
RoHS 3 compliant
Out of stock.
Quantity:
sensors size
(mm)
output max current optimal
range
connec­tor
LED board
1 8.1 × 15.2 RC (digital) 3.5 mA 5 mA 10 mm side-entry

This sensor uses an IR LED and a phototransistor to measure the light reflected from nearby surfaces. It operates from 2.9–5.5 V, with dimmable brightness control independent of the supply voltage. The optimal range is <5 mm, but it can detect high-reflectance objects out to around 30 mm. This version features a high-performance, low-current QTRX sensor with lenses and a connector that works with our 4-pin JST SH-style cables (compatible with SparkFun’s Qwiic and Adafruit’s STEMMA QT cables, but the interface is not I²C).

Pololu item #: 4401
Brand: Pololu supply outlook
Status: Active and Preferred 
RoHS 3 compliant
Out of stock.
Quantity:
sensors size
(mm)
output max current optimal
range
LED board
1 5.0 × 20.0 analog 3.5 mA 5 mA 10 mm

This IR LED/phototransistor pair is great for precisely identifying changes in reflectance (like line detection). It operates from 2.9 V to 5.5 V and offers dimmable brightness control independent of the supply voltage. In general, the closer the object, the higher the contrast between light and dark readings, but high-reflectance objects are generally detectable out to around 30 mm. This version features a high-performance, low-current QTRX sensor with lenses.

Pololu item #: 4441
Brand: Pololu supply outlook
Status: Active and Preferred 
RoHS 3 compliant
Out of stock.
Quantity:
sensors size
(mm)
output max current optimal
range
LED board
1 7.5 × 20.0 analog 3.5 mA 5 mA 10 mm

This IR LED/phototransistor pair is great for precisely identifying changes in reflectance (like line detection). It operates from 2.9 V to 5.5 V and offers dimmable brightness control independent of the supply voltage. In general, the closer the object, the higher the contrast between light and dark readings, but high-reflectance objects are generally detectable out to around 30 mm. This version features a high-performance, low-current QTRX sensor with lenses.

Pololu item #: 4440
Brand: Pololu supply outlook
Status: Active and Preferred 
RoHS 3 compliant
Out of stock.
Quantity:
sensors size
(mm)
output max current optimal
range
connec­tor
LED board
1 8.1 × 15.2 analog 3.5 mA 5 mA 10 mm side-entry

This sensor uses an IR LED and a phototransistor to measure the light reflected from nearby surfaces. It operates from 2.9–5.5 V, with dimmable brightness control independent of the supply voltage. The optimal range is <5 mm, but it can detect high-reflectance objects out to around 30 mm. This version features a high-performance, low-current QTRX sensor with lenses and a connector that works with our 4-pin JST SH-style cables (compatible with SparkFun’s Qwiic and Adafruit’s STEMMA QT cables, but the interface is not I²C).

Pololu item #: 4501
Brand: Pololu supply outlook
Status: Active and Preferred 
RoHS 3 compliant
Out of stock.
Quantity:
sensors size
(mm)
output max current optimal
range
LED board
1 5.0 × 20.0 RC (digital) 30 mA 32 mA 20 mm

This IR LED/phototransistor pair is great for precisely identifying changes in reflectance (like line detection). It operates from 2.9 V to 5.5 V and offers dimmable brightness control independent of the supply voltage. In general, the closer the object, the higher the contrast between light and dark readings, but high-reflectance objects are generally detectable out to around 80 mm. This version features a high-performance QTRXL sensor with lenses and a high-brightness emitter for extra-long range.

Pololu item #: 4541
Brand: Pololu supply outlook
Status: Active and Preferred 
RoHS 3 compliant
Out of stock.
Quantity:
sensors size
(mm)
output max current optimal
range
LED board
1 7.5 × 20.0 RC (digital) 30 mA 32 mA 20 mm

This IR LED/phototransistor pair is great for precisely identifying changes in reflectance (like line detection). It operates from 2.9 V to 5.5 V and offers dimmable brightness control independent of the supply voltage. In general, the closer the object, the higher the contrast between light and dark readings, but high-reflectance objects are generally detectable out to around 80 mm. This version features a high-performance QTRXL sensor with lenses and a high-brightness emitter for extra-long range.

Pololu item #: 4540
Brand: Pololu supply outlook
Status: Active and Preferred 
RoHS 3 compliant
Out of stock.
Quantity:
sensors size
(mm)
output max current optimal
range
connec­tor
LED board
1 8.1 × 15.2 RC (digital) 30 mA 32 mA 20 mm side-entry

This sensor uses an IR LED and a phototransistor to measure the light reflected from nearby surfaces. It operates from 2.9–5.5 V, with dimmable brightness control independent of the supply voltage. The optimal range is <5 mm, but it can detect high-reflectance objects out to around 80 mm. This version features a high-performance QTRXL sensor, with lenses and a high-brightness emitter for extra-long range, and a connector that works with our 4-pin JST SH-style cables (compatible with SparkFun’s Qwiic and Adafruit’s STEMMA QT cables, but the interface is not I²C).

Pololu item #: 4601
Brand: Pololu supply outlook
Status: Active and Preferred 
RoHS 3 compliant
Out of stock.
Quantity:
sensors size
(mm)
output max current optimal
range
LED board
1 5.0 × 20.0 analog 30 mA 32 mA 20 mm

This IR LED/phototransistor pair is great for precisely identifying changes in reflectance (like line detection). It operates from 2.9 V to 5.5 V and offers dimmable brightness control independent of the supply voltage. In general, the closer the object, the higher the contrast between light and dark readings, but high-reflectance objects are generally detectable out to around 80 mm. This version features a high-performance QTRXL sensor with lenses and a high-brightness emitter for extra-long range.

Pololu item #: 4641
Brand: Pololu supply outlook
Status: Active and Preferred 
RoHS 3 compliant
Out of stock.
Quantity:
sensors size
(mm)
output max current optimal
range
LED board
1 7.5 × 20.0 analog 30 mA 32 mA 20 mm

This IR LED/phototransistor pair is great for precisely identifying changes in reflectance (like line detection). It operates from 2.9 V to 5.5 V and offers dimmable brightness control independent of the supply voltage. In general, the closer the object, the higher the contrast between light and dark readings, but high-reflectance objects are generally detectable out to around 80 mm. This version features a high-performance QTRXL sensor with lenses and a high-brightness emitter for extra-long range.

Pololu item #: 4640
Brand: Pololu supply outlook
Status: Active and Preferred 
RoHS 3 compliant
Out of stock.
Quantity:
sensors size
(mm)
output max current optimal
range
connec­tor
LED board
1 8.1 × 15.2 analog 30 mA 32 mA 20 mm side-entry

This sensor uses an IR LED and a phototransistor to measure the light reflected from nearby surfaces. It operates from 2.9–5.5 V, with dimmable brightness control independent of the supply voltage. The optimal range is <5 mm, but it can detect high-reflectance objects out to around 80 mm. This version features a high-performance QTRXL sensor, with lenses and a high-brightness emitter for extra-long range, and a connector that works with our 4-pin JST SH-style cables (compatible with SparkFun’s Qwiic and Adafruit’s STEMMA QT cables, but the interface is not I²C).

Pololu item #: 2458
Brand: Pololu
Status: Active and Preferred 
RoHS 3 compliant
Out of stock.
Quantity:

The QTR-1A reflectance sensor carries a single infrared LED and phototransistor pair in an inexpensive, tiny 0.5" x 0.3" module that can be mounted almost anywhere and is great for edge detection and line following. The reflectance measurement is output as an analog voltage. This sensor is sold in packs of two units.

Pololu item #: 2459
Brand: Pololu
Status: Active and Preferred 
RoHS 3 compliant
Out of stock.
Quantity:

The QTR-1RC reflectance sensor carries a single infrared LED and phototransistor pair in an inexpensive, tiny 0.5" x 0.3" module that can be mounted almost anywhere and is great for edge detection and line following. The output is designed to be measured by a digital I/O line. This sensor is sold in packs of two units.

Pololu item #: 2454
Brand: Pololu
Status: Active and Preferred 
RoHS 3 compliant
Out of stock.
Quantity:

The QTR-L-1A reflectance sensor incorporates a right-angle infrared LED and a right-angle phototransistor in an inexpensive, tiny 0.35″ × 0.3″ module that can be mounted almost anywhere and is great for edge detection and line following. The reflectance measurement is output as an analog voltage. This sensor is sold in packs of two units.

Pololu item #: 2455
Brand: Pololu
Status: Active and Preferred 
RoHS 3 compliant
Out of stock.
Quantity:

The QTR-L-1RC reflectance sensor incorporates a right-angle infrared LED and a right-angle phototransistor in an inexpensive, tiny 0.35″ × 0.3″ module that can be mounted almost anywhere and is great for edge detection and line following. The output is designed to be measured by a digital I/O line. This sensor is sold in packs of two units.

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Pololu QTR Reflectance Sensors
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