There are many types of sensors used in automation and robotics. Gas sensors, light sensors, touch and motion sensors – these are just some of the types, probably the most popular ones. However, one of the most interesting modules extending a given project with a number of new functions are reflection sensors.
Sensors odbiciowe
Photocell for gates - sensors IR
The kit includes: the transmitter and receiver of infrared radiation. Together they create an invisible barrier, which when crossed by a person, an animal or a vehicle, will...Distance sensor, reflective 3,3V/5V - 30mm - Waveshare 9523
The reflective module with IR sensor equipped with digital and analog output. It works with a voltage from 3 V to 5.3 V. It enbales the detection of obstacles in the range from...TCST1103 photoelectric sensor - optocoupler
Slit width: 3 mm. Maximum voltage - 70 Volts .Optical sensor with LM393 comparator - 10mm
Digital module with optical sensor, with a slit of 10 mm. The module has a built-in LM393 comparator because the output is a digital signal. The supply voltage is 5 V. Along...Cytron Maker Reflect - Analog IR reflectance sensor
Maker Reflect is a small reflective sensor equipped with an IR diode that sends out an infrared light beam, which returns to the sensor after reflection from the surface and...QTR-8RC reflectance sensor array - digital - Pololu 961
Strap with eight reflective sensors with digital output. It is powered with the voltage of 5 V or 3.3 V.Photo Interrupter Sensor, Speed Measuring - Waveshare 12225
Digital module with optical sensor, with a gap of 6 mm. The module has a built-in comparator, because of this, the output is a digital signal. Supply voltage is from 3.3 V to 5...QTR-8A reflectance sensor array- analog - Pololu 960
Strap of the eight reflecting sensors with analog outputs. It is powered with the voltage of 5 V or 3.3 V.Reflectance sensor KTIR0711S - with connectors
Module with reflective sensor KTIR0711S powered with the voltage of up to 5 V. It is characterized by small dimensions: 9 x 14 mm. It has soldered goldpin connectors.CNY70 reflective optocoupler sensor
Reflective optocoupler used, for example, to distinguish the edges or for line detection. Case dimensions - 7 x 7 x 6 mm,through hole installation.Gravity - infrared light photo interrupter module 5mm - ITR9608 - 940nm - DFR1129
The Gravity module with the ITR9608 sensor is a precise solution for object detection, based on interrupting the infrared light beam with a wavelength of 940 nm ....- New
Photocell - IR beam interruption sensors
The kit includes: the transmitter and receiver of infrared radiation. Together they create an invisible barrier, which when crossed by a person, an animal or a vehicle, will...Distance sensor, reflective 3,3V/5V - Iduino ST1140
The module is equipped with IR reflective sensor equipped with digital output. It works with a supply voltage from 3.3 V to 5 V. It is applied in the robots tracking the line.Proximity sensor HSDL-9100-021 60mm
Miniature proximity sensor from Avago Technologies to detect objects at a distance from 0 to 60 mm.QTR-1A reflectance sensor - 2pcs. - Pololu 2458
Two modules with QTR reflective sensors. They have an analog output. The supply voltage is 5 V.Cytron LSA08 - strip with reflection sensors and display
Compact strap with eight reflective sensors. It has the function of automatic calibration, LCD display of 2x8, digital and analog outputs, UART, powered with a voltage of 12 V.- Reduced price
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VCNL4040 - Proximity Sensor Breakout - 20cm (Qwiic) - SparkFun SEN-15177
A digital sensor that combines the ability to measure proximity IR and measure the intensity of ambient light. The module allows to detect obstacles in the range of 0 to 20 cm....KTIR0711S reflective optocoupler sensor - 5pcs
Reflective optocoupler used, for example, to distinguish the edges. The system is closed in a small, surface soldered case with dimensions: 2.7 x 3.4 mm. Items are sold in...Photoelectric sensor SPDT E3JK-R4M1 12V IP65 - 4m
Photoelectric transmitting sensor. It detects the objects by the method of reflection. Detection range is up to 4 meters. It has Light-ON operation mode. It is powered with...Grove - RPR-220 reflectance sensor v1.2
Module from the Grove series is based on a reflective sensor RPR-220. It consists of LED emitting the infrared light and phototransistor of high sensitivity. It is supplied...Grove - RS-06WD reflectance sensor v1.1
Module from the Grove is equipped with the reflective sensor RS-06WD. It consists of LED emitting the infrared light and phototransistor of high sensitivity. It is supplied...Cytron Maker Line -Trim with reflective sensors
The Cytron module equipped with 5 reflective sensors (pair : IR diode and phototransistor) is able to track 13 to 30 mm wide lines in white and black. The sensor has 2...See also
- Inductive sensors
- Hall effect sensors
- Led motion detectors
- Optical sensors
- Twilight sensors
- Resistance sensors
- Door sensors
- Piezoelectric sensors
- RPM sensors
- Oxygen sensors
- Tilt sensors
- Accelerometers
- Alarm sensors
- 9DoF IMU sensors
- Pressure sensors
- Air quality sensors
- Sound sensors
- Gesture sensors
- Gas sensors
- Limit switches
- Sensors of light and color
- Magnetic sensors
- Medical sensors
- Pressure sensors
- Distance sensors
- Inductive contactless sensors
- Weather sensors
- Liquid level sensors
- Current sensors
- Flow sensors
- Motion sensors
- Temperature sensors
- PT100 temperature probes
- Humidity sensors
- Fingerprint readers
- Encoders
- Photoresistors
- Phototransistors
- IR receivers
- Magnetometers
- Gyros
- Sensor sets
- Grove modules
- Gravity modules
Principle of operation and connection of reflective sensors
One of the simplest implementations of an optical sensor is an infrared LED paired with a phototransistor. The phototransistor is connected to the supply voltage source through a resistor that forms a voltage divider. At the output of this divider, a voltage ranging from 0V to typically 5V is obtained as a representation of the infrared reflection, with a smaller value representing a stronger infrared reflection. The analog output of the sensor, providing the received voltage, can be connected for further reading in various ways. The easiest way to do this is to connect the sensor output to the analog input of the ADC converter in the microcontroller or to the binary input using a software comparator. There is also a solution of connecting the sensor to a hardware comparator with an adjustable threshold for changing the logical state (e.g. LM393 integrated circuit). The state at the comparator output is then read at the microcontroller's binary input. Due to the small size of the sensors, they can be easily connected in parallel in the form of a strip, which allows for easy detection of edges, walls and other obstacles, including the ability to measure the distance from them.
Measurement accuracy of reflective sensors
Solutions such as a laser sensor or an optoelectronic sensor have sufficiently good measurement accuracy and work well in many hobby projects. However, to obtain the best possible accuracy of the sensor in the application in which it will be used, it must be calibrated. Calibration of a proximity sensor is an important process because there are no perfect measurement sensors and, despite the repeatable production technology, two identical sensors may output different voltage values, even if they work in the same environmental conditions. The materials from which sensors are made also go through natural aging processes, which requires their periodic recalibration. It is best to perform calibration in software, e.g. in the Arduino program code working with the sensor. The ideal calibration of the sensor is when the measured distance value corresponds to the voltage at the sensor output approximately in direct proportion.
Reflective sensors - FAQ
Reflective sensors are used in industrial automation. A special application of reflective sensors are linefollower robots that follow a line painted on a given surface (e.g. the floor). The operation of reflective sensors is based on the phenomenon of interrupting the light flux that is sent from the sensor and then reflected by the reflector. Depending on the specific type of reflectance sensor, these electronic components use light that is invisible to the human eye (e.g. ultraviolet or infrared rays) or visible light. A common feature of reflective sensors is the transmitter and receiver enclosed in one housing. The state in which the light stream is interrupted changes the signal output from the sensor.
Reflective sensors are used, among others, in industrial automation. They are installed in linefollower robots, whose main task is to follow a painted line (e.g. on a warehouse floor). The principle of operation of reflectivity sensors is to emit light and reflect it using a reflector. When the light stream is interrupted, the signal changes.