TCRT5000 IR Sensor : Pin Configuration & Its Applications

The reflective IR sensors like TCRT5000L and TCRT5000 comprise an IR transmitter (photodiode) and IR receiver (photo-transistor) within a leaded package. These kinds of IR sensors look like visible light. Here, the package of the TCRT5000 IR sensor includes two mounting clips where the TCRT5000L IR sensor is the long lead version. These types of sensors are mainly used in different Arduino modules for detecting or avoiding obstacles and are also used in line following robots.

In this IR sensor package, the photodiode is available in blue color whereas the phototransistor is black color. The transmitter’s IR range is 950nm whereas the receiver includes a filter for daylight blocking to reduce interference from detectable light. This article discusses an overview of a TCRT5000 IR sensor and its working with applications.

What is TCRT5000 IR Sensor?

The TCRT5000 Infrared sensor mainly includes an IR Tx (transmitter) & and IR Rx (receiver). Here transmitter and receivers are Photodiode & a Phototransistor. Once the voltage supply is provided to the IR Tx unit then it immediately transmits & emits IR signals. Once these signals crash through an object, then the IR receiver gets the signals. Here the transmitter functions similar to a transistor, apart from the base terminal are excited through light.

The TCRT5000 IR sensor unit includes a coupled Photodiode & a Phototransistor in a single package. The photodiode (Tx) in this sensor includes two pins namely anode & cathode which are mainly used for generating infrared signals In the same way, the Phototransistor in this sensor includes two pins like emitter & collector. These two pins play a key role to read the infrared signal that is reproduced back.

This type of infrared sensor is mainly used to sense the existence of an object by using some specific programming; it can also measure the object distance ahead of it. However, the distance can be measured simply for a small range of objects due to environmental annoyance. So this sensor is useful if you want to measure the object’s distance ahead of it.

This sensor is either used as an analog/digital sensor. If we simply want to sense the existence of a target or object, then this sensor can be used as a digital sensor. If we want to measure the distance of the target then it is used as an analog sensor.


Pin Configuration

The pin configuration of the TCRT5000 IR sensor includes the following. This sensor includes an IR transmitter and IR receiver which include four pins totally which are discussed below.

TCRT5000 IR Sensor PIn Configuration
TCRT5000 IR Sensor PIn Configuration
  • Anode: This is a positive pin of the infrared transmitter IR transmitter (Photo Diode)
  • Cathode: This is a negative pin of the infrared transmitter IR transmitter (Photo Diode)
  • Collector: This is the collector terminal of the IR receiver (Photo Transistor)
  • Emitter: This is the emitter terminal of the IR receiver (Photo Transistor)

TCRT5000 IR Reflective Sensor Module

The IR reflective sensor module uses a TCRT5000 IR sensor to sense distance & color. This kind of module includes an IR transmitter and receiver. Here, IR Tx generates an infrared signal continuously then reflects through an obstacle and is detected through the IR receiver.

TCRT5000 IR Sensor Module
TCRT5000 IR Sensor Module

The TCRT5000 IR sensor module mainly includes different parts like TCRT5000 IR sensor, power LED, reflective sensor, adjustment of sensitivity, and output LED. This sensor module is frequently used in different robots like object sorting and line following because this module detects the surface whether that is black or white. The range of measuring distance ranges from 1mm – 8mm & the middle point is approximately 2.5mm.

In this module, the potentiometer is available to regulate the sensitivity. Once this module is activated through power, then the IR diode will emit the IR signal frequently. Once the emitted IR light has not been reflected then the receiver diode will be in the off condition & the output pin will be on the module like i.e. DO will be LOW.

This module has some features like a strong drive capability, clear signal & good waveform. So this module simply provides maximum performance for different applications which includes paper shredders, fax machines, paper testing, obstacle detection, white and black detection, etc.

Features & Specifications

The features and specifications of the TCRT5000 IR Sensor include the following.

  • It is available in a leaded package
  • The type of detector used is photo-transistor
  • The Peak operating distance is 2.5 mm.
  • Collector current ranges from 0.2 mm – 15 mm
  • The typical o/p current blow test (IC) is 1 mA.
  • Blocking filter for daylight
  • The wavelength of the emitter is 950 nm
  • Infrared sensor including the o/p of transistor
  • The operating voltage is 5V
  • The forward current of the diode is 60mA
  • Output data is analog/digital
  • The Collector current of the transistor is 100mA
  • Operating temperature ranges from -25°C to +85°C

The equivalent TCRT5000 IR sensor is RPR220 and other infrared sensors are IR LED, IR Photodiode, qtr-1rC, GP2Y0A21, TSOP, etc.

How to use/Circuit Diagram

Measuring the distance using an infrared sensor is possible. An IR beam can be transmitted toward the object & the reflected ray is captured through the photodiode. Here, the photodiode is used to measure the light intensity. The infrared diode does not determine the IR light intensity however it is also very responsive to noticeable light. The IR light’s intensity can be recorded with the help of a photodiode that signifies the distance between the object & sensor.

This technique is not very correct & its output is also non-linear. As discusses earlier, this technique suffers from ambient sound, thus users need to adjust it every time to change the ambient condition.

The TCRT500 IR sensor circuit is shown below. In this circuit, the IR sensor includes a photodiode & a phototransistor where these two components work like a transmitter and a receiver.

TCRT5000 IR Sensor Circuit
TCRT5000 IR Sensor Circuit

Here, the photodiode can be activated through a 220R resistor whereas the phototransistor is connected to GND with 10K of a resistor. The transistor in the circuit does not contain a base pin as the transistor biasing is mainly controlled through the received IR light. As a result, the infrared light from the photodiode strikes a target & gets back toward the phototransistor for biasing it.

This IR sensor can be used as either analog or digital sensor based on application. The main disadvantages of this sensor are, they simply get affected by the conditions of the environment.

Similar to the phototransistor, it will not simply respond to the infrared light using the photodiode however it can also respond to the infrared light from different light sources which are available commonly.

This problem is normally stopped by executing noise cancelation within the program. So photodiode controlling itself throughout an MCU or MPU’s GPIO pin, we can deactivate the diode & need to verify how much noise the transistor in the sensor is reading so that we can activate the photodiode to calculate the change within the values through invalidating the noise present while the photodiode was deactivated.

Where to use TCRT5000 IR Sensor/Applications

The applications of the TCRT5000 IR sensor include the following.

  • TCRT5000 IR sensor is used in IR sensor modules
  • It is used in the applications of proximity detection
  • Used in maze solver robots/ Line follower
  • Used in Obstacle avoidance/detection
  • This TCRT5000 IR sensor is used to verify the existence of a physical object like noticing a coil within a coin sorting machine.
  • Used to detect the color on a white or black scale and this principle is used in line following robot project. The dissimilar shades will modify the reflected IR light level.
  • The TCRT5000 IR sensor is normally used to calculate the distance of the object or target.

Thus, this is all about an overview of a TCRT5000 IR sensor datasheet which includes its pin configuration, features, specifications, circuit working with applications. Here is a question for you, what are the drawbacks of a TCRT5000 IR sensor?