// The second parameter, of type bool, can indicate that the data from the receiver is inverted.

• Function begin();
• Purpose: initialization of work with the IR receiver
• Syntax: begin();
• Options: None.
• Return values: None.
• Note: Called once in setup code.

IR.begin(); // Initiate work with the IR receiver

• Function check();
• Purpose: Checking the availability of data received from the remote control.
• Syntax: check([ HOLD ]);
  • HOLD - an optional parameter, type bool - indicating that it is necessary to respond to holding the remote control buttons.
• Return values: bool - whether the data from the remote control was accepted or not.
• Note: If the function is called without a parameter, or it is false, then the function will only respond to signals from the remote control when its buttons are pressed, and if you specify true, the function will respond to both pressing and holding the remote control buttons.
• Note: Called once in setup code.

Function protocol();

• Purpose: Receiving, setting or resetting the data transfer protocol.
• Syntax: protocol([ PARAMETER ]);
• Getting the protocol: If the function is called without a parameter, it will return a string of 25 characters + the end of line character. The bits of this line carry information about the type of data transfer protocol of the remote control whose data was last received. This line can be used to set the protocol for the IR transmitter or IR receiver (see below).
• Setting the protocol: If the function is called with a parameter in the form of a string of 25 protocol characters + the end of line character, then after this, the chek() function will respond only to remote controls that comply with the specified data transfer protocol.
• Protocol reset: If the function is called with the IR_CLEAN parameter, then the chek() function will again respond to signals from any remote control.
• Receiving protocol parameters: If the function is called with an int parameter, from 0 to 17, then it will return not a protocol string, but an int value with one of the parameters of the data transfer protocol of the console whose data was last received:
  • 0 - encoding type:
    • IR_UNDEFINED - encoding type is undefined;
    • IR_PAUSE_LENGTH - long pause coding;
    • IR_PULSE_LENGTH - encoding by long (width) pulse (PWM);
    • IR_BIPHASIC - biphasic coding;
    • IR_BIPHASIC_INV - biphasic encoding with inverted bits;
    • IR_NRC - repeat packets are identical, but the first and last packets are special;
    • IR_RS5 - PHILIPS encoding with toggle bit;
    • IR_RS5X - PHILIPS encoding with toggle bit;
    • IR_RS6 - PHILIPS encoding with toggle bit.
  • 1 - carrier frequency of data transmission (in kHz);
  • 2 - declared number of information bits in 1 packet;
  • 3 - declared number of information bits in the repeat packet;
  • 4 - pause duration between packets (in ms);
  • 5 - pulse duration in the start bit (in μs);
  • 6 - pause duration in the start bit (in μs);
  • 7 - pulse duration in stop bit (in μs);
  • 8 - pause duration in the stop bit (in μs);
  • 9 - pulse duration in the restart or toggle bit (in μs);
  • 10 - pause duration in the restart or toggle bit (in μs);
  • 11 - position of the restart or toggle bit in the packet (bit no.);
  • 12 - maximum pulse duration in information bits (in μs);
  • 13 - minimum pulse duration in information bits (in μs);
  • 14 - maximum pause duration in information bits (in μs);
  • 15 - minimum pause duration in information bits (in μs);
  • 16 - start bit presence flag (true/false);
  • 17 - stop bit presence flag (true/false);
  • 18 - flag for the presence of the restart or toggle bit (true/false);
  • 19 - repeat packet type (0-none, 1-with inverted bits, 2-identical to informational, 3-unique);
• Return values: Depends on the presence and type of the parameter.
• Note: If a protocol was previously set, then attempting to retrieve the protocol, or protocol parameters, will return the values ​​of the previously set protocol, and not the data transfer protocol of the console whose data was last received.
• Note: Called once in setup code.

IR.protocol(IR_CLEAN); // Reset the previously installed protocol. Now the receiver will again respond to any remote control. if(IR.check())( Serial.println(IR.protocol()); ) // Get the protocol. As soon as the receiver receives the data, a string of 25 protocol characters will be displayed on the monitor. if(IR.check())( Serial.println(IR.protokol(12)); ) // Get one of the protocol parameters. As soon as the receiver receives the data, the monitor will display the maximum pulse duration of the information bit in microseconds.

• Data variable
• Value: Returns the button code received from the remote control;

if(IR.check())( Serial.println(IR.data); ) // Print the code of the pressed button, if accepted

• length variable
• Value: Returns the size of the button code, in bits;

if(IR.check())( Serial.println(IR.length); ) // Print the size of the pressed button code, if accepted

• key_press variable
• Value: Returns a flag indicating that the remote control button is being pressed rather than held;

if(IR.check(true))( if(IR.key_press)(Serial.println("PRESS");) // The text will be printed 1 time when the button is pressed else (Serial.println("HOLD ");) // The text will be displayed continuously while the button is held down)

• control of robots, moving, flying and floating models, household and specialized equipment.
• turning on/off lighting, heating, ventilation, watering, etc.
• opening/closing doors, blinds, roof windows, vents, etc.

The IR receiver is a standard device that connects to the COM (RS-232) port and serves to remotely control the robot.

One of possible schemes IR receiver. Any 5-volt infrared receiver used in household equipment (TVs) will be suitable for the IR receiver. For example: TSOP1836, IS1U60L, GP1U52X, SFH506-36 or our domestic TK1833. The KREN5A voltage stabilizer is necessary to power the IR receiver with 5 V voltage, because 12 volts are supplied from the 7th pin of the COM port. The resistor can be selected from the range of 3-5 kOhm, capacitor 4.7-10 μF. Any low-power diode.

In the above circuit, the output signal is supplied to 1 contact COM port(DCD). This contact is not used by a standard mouse for a COM port, so if you do not have enough free COM port, this circuit can be used in parallel with a mouse (but not with a modem)! The output signal can be sent not only to the DCD, but also to other pins, such as CTS or DSR. All these parameters can be set in a program that works in the IR receiver. There are several program options, the most common is WinLIRC. I can also recommend using the Girder program.

Pinout and appearance of the main elements of the circuit

From left to right - two types of 5-volt IR receivers, and a KREN5A voltage stabilizer chip.

COM port pinout

Pinout and description of COM port contacts (25 pin).

The IR receiver plays an important role in our everyday life. With the help of this microcircuit, we have the opportunity to control modern household appliances, a TV, a stereo system, a car radio, and an air conditioner. This allows us to do this, the remote control (RC), let's take a closer look at its operation, circuit, purpose and testing. In the article, how to check the IR receiver yourself.

What is an IR receiver and how does it work?

This is an integrated circuit, its direct and main task is to receive and process the infrared signal, which is what the remote control emits. This signal is used to control the equipment.

This microcircuit is based on a pin photodiode, a special element, with a p-n junction and an i region between them, an analogue of the base of a transistor, as in a sandwich, so here is the abbreviation pin, a unique element in its own way.

It is turned on in reverse and does not pass electricity. The IR signal enters the i region, and it conducts current, converting it into voltage.

The next stages are an integrating filter, an amplitude detector, and at the finish line, output transistors await them.

As a rule, there is no particular point in buying a new IR receiver in a store, since it can be easily unsoldered from various electronic boards. If you are assembling a device for checking the remote control from scrap materials, without knowing the exact marking of the device, then you can determine the pinout yourself.

We will need a multimeter, a power supply or several batteries, connecting wires, installation can be done hanging.

It has three outputs, one is GND, plus 5 volts is supplied to the second, and the out signal comes out from the third. We connect the power to the first and second legs, respectively, and remove the voltage from the third.

It is in a state of waiting for a signal from the remote control, and on the multimeter we see five volts. We begin to switch channels or press other buttons by pointing the remote control at him.

If it is working, then the voltage will drop by about 0.5-1 volt. If everything happens as written here, the device is working, otherwise the element is faulty.

How to determine the pinout of an infrared receiver

For example, I took a microcircuit completely unknown to me, which was lying in a box with elements, the “minus” was determined by the point that is on the back of the element, the “plus” was experimentally determined through a resistor. I didn’t risk anything, since he was initially a worker, there was no hope.

To determine the pinout of the IR receiver, if it is soldered into the board, look at it, there may be pin markings. If nothing is written there, inspect the element itself, look for its name, and then look on the Internet for characteristics and data, this is a very competent way of doing things. Following the instructions, how to check the IR receiver yourself.

diagram from the magazine "Young Technician".

An interesting direction in radio electronics, which has supplemented this electronics with new advantages of “invisible” light (infrared light). So I propose a circuit of a simple (for example) receiver and transmitter based on infrared rays. Basis: operational amplifier k140ud7 (I have ud708 here), emitting and receiving IR photodiodes, ULF (k548un1a (b,c - indices) - for two channels) (although where to “turn on” the second channel of the amplifier is up to you to decide - the transmitter circuit is designed for one channel, i.e. mono). Power supply for the device: I generally recommend it with decent current stabilization (otherwise the “dandy” adapter irritates the background of the “network”). Method: the amplitude-modulated signal of the transmitter is amplified by the receiver 1000 times.

How the device works. I suggest you watch a short video testing the IR remote control “by ear”. You can quickly check the functionality and signal strength by sound.

IR receiver and IR transmitter circuit

When assembling, capacitors C1 and C2 should be as close to the amplifier as possible! You can connect high-impedance headphones to the output (low-impedance ones require a separate ULF). Photodiode FD7 (I have FD5.. some kind of “tablet” with a focusing lens - I don’t remember the exact name); 0.125W resistors: R1 and R4 set the signal amplification factor by 1000 times. The receiver is set up simply: the photodiode is directed to a source of IR radiation, for example, a 220V-50Hz lamp: the filament will be fonit with a frequency of 50Hz or the remote control from the TV (video, etc.). The sensitivity of the receiver is high: it normally receives signals reflected from the walls .

The transmitter has AL107a IR LEDs: any will do. R2 2 kOhm, C1 1000μFx25V, C2 200μFx25V, any transformer too. Although it is quite possible to do without a transformer - supply an amplified audio signal to capacitor C2.

Device diagram

Recently, out of necessity, I assembled an IR receiver for testing IR remote controls (TVs and DVDs). After finalizing the circuit, I installed a mono ULF TDA7056. This amplifier has good gain characteristics of about 42 dB; operates in a voltage range from 3V to 18V, which allowed the IR receiver to operate even at a voltage of 3V; TDA gain range from 20 Hz to 20 kHz (UD708 passes up to 800 kHz) is quite enough to use the receiver as audio accompaniment; has short circuit protection on all “legs”; protection against "overheating"; weak self-interference coefficient. Overall, I liked this compact and reliable ULF (our price is 90 rubles).
There is to him with. Figure 1 shows an example of using an amplifier.

Photo TDA7056

Fig.1. Amplifier circuit with TDA7056

The result is an IR receiver, Fig. 2, which operates in the voltage range from 3V to 12V. I recommend using batteries or rechargeable batteries to power the receiver. When using a power supply, a stabilized source is required, otherwise the background of the 50Hz network will be heard, which amplifies the UD708. If the device is located near a source of mains voltage or radio emissions, interference may occur. To reduce interference, it is necessary to include capacitor C5 in the circuit. The TDA7056 is designed for a 16 Ohm output speaker, unfortunately I don’t have one. I had to use a 4 ohm 3 watt speaker, which was connected through a one watt 50 ohm resistor. Too low speaker coil resistance causes excess power and overheats the amplifier. In general, due to the additional resistor, the ULF does not heat up, but provides quite acceptable amplification.

Fig.2. IR receiver circuit with ULF

Photo of IR receiver

In this lesson we will look at connecting an IR receiver to Arduino. We will tell you which library should be used for an IR receiver, demonstrate a sketch for testing the operation of an infrared receiver from a remote control, and analyze commands in C++ to receive a control signal.

IR receiver device. Principle of operation

Infrared radiation receivers received wide application in electronic technology, due to its affordable price, simplicity and ease of use. These devices allow you to control devices using a remote control and can be found in almost any type of equipment.

The operating principle of an IR receiver. Processing the signal from the remote control

The IR receiver on Arduino is capable of receiving and processing an infrared signal in the form of pulses of a given duration and frequency. Typically, an IR receiver has three legs and consists of the following elements: a PIN photodiode, an amplifier, a bandpass filter, an amplitude detector, an integrating filter, and an output transistor.

Under the influence of infrared radiation in a photodiode, which has between p And n regions created an additional region of semiconductor ( i-region), current begins to flow. The signal goes to an amplifier and then to a bandpass filter, which protects the receiver from interference. Interference can be caused by any household appliance.

The bandpass filter is set to a fixed frequency: 30; 33; 36; 38; 40 and 56 kilohertz. In order for the signal from the remote control to be received by the Arduino IR receiver, the remote control must be at the same frequency as the filter in the IR receiver is set to. After the filter, the signal goes to an amplitude detector that integrates the filter and the output transistor.

How to connect an IR receiver to Arduino

The housings of infrared receivers contain an optical filter to protect the device from external electromagnetic fields; they are made of a special shape to focus the received radiation on a photodiode. To connect the IR receiver to Arduino UNO They use three legs that connect to the ports - GND, 5V and A0.

For this lesson we will need the following details:

• Arduino Uno board;
• Bread board;
• USB cable;
• IR receiver;
• Remote control;
• 1 LED;
• 1 resistor 220 Ohm;
• Wires “folder-folder” and “folder-female”.

Connection diagram of the IR receiver to the Arduino analog port

Connect the IR receiver according to the diagram and the LEDs to pins 12 and 13 and upload the sketch.

#include // connect the library for the IR receiver IRrecv irrecv(A0); // indicate the pin to which the IR receiver is connected decode_results results; void setup () // procedure setup ( irrecv.enableIRIn (); // start receiving an infrared signal pinMode(13, OUTPUT); // pin 13 will be the output pinMode(12, OUTPUT); // pin 12 will be the output pinMode(A0,INPUT); // pin A0 will be the input (eng. “intput”) Serial.begin(9600); // connect the port monitor) void loop () // procedure loop ( if (irrecv.decode (&results)) // if the data has arrived, execute the commands( Serial . println ( results . value ); // send the received data to the port // turn on and off the LEDs, depending on the received signal if (results.value == 16754775) ( digitalWrite (13, HIGH); ) if (results.value == 16769055) ( digitalWrite (13, LOW); ) if (results.value == 16718055) ( digitalWrite (12, HIGH); ) if (results.value == 16724175) ( digitalWrite (12, LOW); ) irrecv.resume (); // receive the next signal on the IR receiver } }

Explanations for the code:

1. The IRremote.h library contains a set of commands and allows you to simplify the sketch;
2. The decode_results statement assigns the variable name results to the received signals from the remote control.

What to pay attention to:

1. To be able to control the inclusion of the LED, you need to turn on the port monitor and find out what signal is sent by this or that button on the remote control;
2. The obtained data should be entered into the sketch. Change the eight-digit code in the sketch after the double equal sign if (results.value == 16769055) to your own.

IR receiver device, operation and testing

IR receivers of infrared radiation have become widespread in television, household, medical equipment and other equipment. They can be seen in almost any type of electronic equipment; they are controlled using a remote control.

Typically, an IR receiver microassembly has three or more pins. One is common and is connected to the power supply minus GND, the other to the plus V s, and the third is the output of the received signal Out.

Unlike a standard IR photodiode, an IR receiver is capable of not only receiving, but also processing an infrared signal in the form of pulses of a fixed frequency and a given duration. This protects the device from false positives, from background radiation and interference from other household appliances emitting in the IR range. Fluorescent energy-saving lamps with an electronic ballast circuit can create quite strong interference for the receiver.

The microassembly of a typical IR radiation receiver includes: PIN photodiode, variable amplifier, bandpass filter, amplitude detector, integrating filter, threshold device, output transistor

A PIN photodiode is from the family of photodiodes, in which another region of its own semiconductor (i-region) is created between the n and p regions - this is essentially a layer of pure semiconductor without impurities. It is this that gives the PIN diode its special properties. In the normal state, no current flows through the PIN photodiode, since it is connected to the circuit in the opposite direction. When electron-hole pairs are generated in the i-region under the influence of external IR radiation, current begins to flow through the diode. Which then goes to a variable amplifier.

Then the signal from the amplifier goes to a bandpass filter that protects against interference in the IR range. The bandpass filter is set to a strictly fixed frequency. Typically, filters are used that are set to a frequency of 30; 33; 36; 36.7; 38; 40; 56 and 455 kilohertz. In order for the signal emitted by the remote control to be received by the IR receiver, it must be modulated with the same frequency to which the filter is configured.

After the filter, the signal goes to an amplitude detector and an integrating filter. The latter is necessary to block short single signal bursts that may appear from interference. Next, the signal goes to the threshold device and the output transistor. For stable operation, the amplifier's gain is adjusted by an automatic gain control (AGC) system.

The housings of IR modules are made of a special shape that facilitates focusing of the received radiation onto the sensitive surface of the photocell. The housing material transmits radiation with a strictly defined wavelength from 830 to 1100 nm. Thus, the device uses an optical filter. To protect internal elements from external influences. fields an electrostatic screen is used.

Since the IR signal receiver is a specialized microassembly, in order to ensure its operation it is necessary to apply a supply voltage to the microcircuit, usually 5 volts. The current consumption will be about 0.4 - 1.5 mA.

If the receiver does not receive a signal, then in the pauses between bursts of pulses the voltage at its output practically corresponds to the supply voltage. It's between GND and the signal output pin can be measured using any digital multimeter. It is also recommended to measure the current consumed by the microcircuit. If it exceeds the standard one (see the reference book), then most likely the microcircuit is defective.

So, before starting the module test, be sure to determine the pinout of its outputs. Usually this information is easy to find in our mega-directory of electronics datasheets. You can download it by clicking on the picture on the right.

Let's check it on the TSOP31236 chip; its pinout corresponds to the figure above. We connect the positive terminal from the homemade power supply to the positive terminal of the IR module (Vs), and the negative terminal to the GND terminal. And we connect the third OUT pin to the positive probe of the multimeter. We connect the negative probe to the common GND wire. Switch the multimeter to DC voltage mode at 20 V.

As soon as packets of infrared pulses begin to arrive at the photodiode of the IR microassembly, the voltage at its output will drop by several hundred millivolts. In this case, it will be clearly visible how the value on the multimeter screen decreases from 5.03 volts to 4.57. If we release the remote control button, the screen will again display 5 volts.

As you can see, the IR radiation receiver responds correctly to the signal from the remote control. This means the module is OK. In a similar way, you can check any modules in an integrated design.

The infrared remote control is one of the most simple ways interaction with electronic devices. So, almost every home has several such devices: a TV, a stereo system, a video player, an air conditioner. But the most interesting use of an infrared remote control is remote control of a robot. Actually, in this lesson we will try to implement this control method using the popular Arduino Uno controller.

1. IR remote control

2. IR sensor

• carrier frequency: 38 kHz;
• supply voltage: 2.7 - 5.5 V;
• current consumption: 50 µA.

3. Connection

• then on the left there will be an output to the controller,
• in the center - negative power contact (ground),
• and on the right - the positive power contact (2.7 - 5.5V).

4. Program

Then, we restart the Arduino IDE and try to load the program onto the controller again.

• Now that we know which codes correspond to the remote control buttons, we try to program the controller to turn on and turn off the LED when the volume buttons are pressed. To do this we need codes (may vary depending on the remote control):
• FFA857 - increase volume;