10 min

Experience the future of IR data exchange with TFDU4101, MCP2120 and ATmega328

Send and receive Infrared (IR) serial data

IrDA2 Click with Arduino UNO Rev3

Published Feb 14, 2024

Click board™

IrDA2 Click

Dev Board

Arduino UNO Rev3


NECTO Studio



Achieve fast and stable infrared data communication, covering a more than 1m range and speeds up to 115.2 kbit/s



Hardware Overview

How does it work?

IrDA 2 Click is based on the MCP2120, a high-performance fully-static infrared encoder/decoder from Microchip for sending and receiving IR serial data from the infrared transceiver module, the TFDU4101 from Vishay semiconductor. This way, the MCP2120 adds IR capability to any embedded application with serial data. The data from a standard UART is encoded (modulated) and output as electrical pulses to the IR Transceiver. Besides, the IR Transceiver also receives and outputs electrical pulses, which the MCP2120 decodes (demodulates) and transmits by the UART interface. The latest IrDAR physical layer standard performs this modulation and demodulation method for fast infrared data communication, supporting IrDA speeds up to 115.2kbit/s. Integrated within the TFDU4101 transceiver module is a photo pin diode, an infrared emitter (IRED), and a low-power control

IC to provide a total front-end solution in a single package. This Click board™ covers the full IrDA range of more than 1m and can be turned on or off through the EN pin routed to the CS pin of the mikroBUS™ socket; hence, offering a switch operation to turn ON/OFF power delivery to the MCP2120. The MCP2120 will encode and decode serial data at the selected data or baud rate. The selection can be made by positioning SMD jumpers labeled as BR SEL in an appropriate position marked as 1 or 0. Also, the software baud rate selection is selected if all these jumpers are in a high (1) position. For any other inputs, the hardware select mode is active. This setting is latched when the MCP2120 is reset from the RST pin of the mikroBUS™ socket. After an MCP2120 reset, changing the value of the baud pins does not affect the device’s baud rate. Software baud data

rate is intended for use with systems where switching data rates must be performed frequently between the MCP2120 and the embedded host. In software baud mode, the MCP2120 differentiates between data and commands. This feature is controlled via the MOD pin routed to the AN pin of the mikroBUS™ socket. The MOD pin is used to switch between command and data modes, and when the MOD pin is in a low state, the MCP2120 is in command mode; otherwise, the MCP2120 is in data mode. This Click board™ can operate with either 3.3V or 5V logic voltage levels selected via the PWR SEL jumper. This way, both 3.3V and 5V capable MCUs can use the communication lines properly. Also, this Click board™ comes equipped with a library containing easy-to-use functions and an example code that can be used as a reference for further development.

IrDA2 Click hardware overview image

Features overview

Development board

Arduino UNO is a versatile microcontroller board built around the ATmega328P chip. It offers extensive connectivity options for various projects, featuring 14 digital input/output pins, six of which are PWM-capable, along with six analog inputs. Its core components include a 16MHz ceramic resonator, a USB connection, a power jack, an

ICSP header, and a reset button, providing everything necessary to power and program the board. The Uno is ready to go, whether connected to a computer via USB or powered by an AC-to-DC adapter or battery. As the first USB Arduino board, it serves as the benchmark for the Arduino platform, with "Uno" symbolizing its status as the

first in a series. This name choice, meaning "one" in Italian, commemorates the launch of Arduino Software (IDE) 1.0. Initially introduced alongside version 1.0 of the Arduino Software (IDE), the Uno has since become the foundational model for subsequent Arduino releases, embodying the platform's evolution.

Arduino UNO Rev3 double side image

Microcontroller Overview

MCU Card / MCU




MCU Memory (KB)


Silicon Vendor


Pin count


RAM (Bytes)


You complete me!


Click Shield for Arduino UNO has two proprietary mikroBUS™ sockets, allowing all the Click board™ devices to be interfaced with the Arduino UNO board without effort. The Arduino Uno, a microcontroller board based on the ATmega328P, provides an affordable and flexible way for users to try out new concepts and build prototypes with the ATmega328P microcontroller from various combinations of performance, power consumption, and features. The Arduino Uno has 14 digital input/output pins (of which six can be used as PWM outputs), six analog inputs, a 16 MHz ceramic resonator (CSTCE16M0V53-R0), a USB connection, a power jack, an ICSP header, and reset button. Most of the ATmega328P microcontroller pins are brought to the IO pins on the left and right edge of the board, which are then connected to two existing mikroBUS™ sockets. This Click Shield also has several switches that perform functions such as selecting the logic levels of analog signals on mikroBUS™ sockets and selecting logic voltage levels of the mikroBUS™ sockets themselves. Besides, the user is offered the possibility of using any Click board™ with the help of existing bidirectional level-shifting voltage translators, regardless of whether the Click board™ operates at a 3.3V or 5V logic voltage level. Once you connect the Arduino UNO board with our Click Shield for Arduino UNO, you can access hundreds of Click boards™, working with 3.3V or 5V logic voltage levels.

Click Shield for Arduino UNO accessories 1 image

Used MCU Pins

mikroBUS™ mapper

Mode Selection
Power Supply
Power Supply

Take a closer look


IrDA2 Click Schematic schematic

Step by step

Project assembly

Click Shield for Arduino UNO front image hardware assembly

Start by selecting your development board and Click board™. Begin with the Arduino UNO Rev3 as your development board.

Click Shield for Arduino UNO front image hardware assembly
Arduino UNO Rev3 front image hardware assembly
Barometer 13 Click front image hardware assembly
Prog-cut hardware assembly
Arduino UNO Rev3 MB 1 - upright/background hardware assembly
Necto image step 2 hardware assembly
Necto image step 3 hardware assembly
Necto image step 4 hardware assembly
Necto image step 5 hardware assembly
Necto image step 6 hardware assembly
Arduino UNO MCU Step hardware assembly
Necto No Display image step 8 hardware assembly
Necto image step 9 hardware assembly
Necto image step 10 hardware assembly
Debug Image Necto Step hardware assembly

Track your results in real time

Application Output

After loading the code example, pressing the "DEBUG" button builds and programs it on the selected setup.

Application Output Step 1

After programming is completed, a header with buttons for various actions available in the IDE appears. By clicking the green "PLAY "button, we start reading the results achieved with Click board™.

Application Output Step 3

Upon completion of programming, the Application Output tab is automatically opened, where the achieved result can be read. In case of an inability to perform the Debug function, check if a proper connection between the MCU used by the setup and the CODEGRIP programmer has been established. A detailed explanation of the CODEGRIP-board connection can be found in the CODEGRIP User Manual. Please find it in the RESOURCES section.

Application Output Step 4

Software Support

Library Description

This library contains API for IrDA 2 Click driver.

Key functions:

  • irda2_generic_write - This function writes a desired number of data bytes by using UART serial interface

  • irda2_generic_read - This function reads a desired number of data bytes by using UART serial interface

  • irda2_reset - This function executes a device reset operation

Open Source

Code example

This example can be found in NECTO Studio. Feel free to download the code, or you can copy the code below.

 * @file main.c
 * @brief IrDA 2 Click Example.
 * # Description
 * This example demonstrates the use of an IrDA 2 click board by showing
 * the communication between the two click boards.
 * The demo application is composed of two sections :
 * ## Application Init 
 * Initalizes device and makes an initial log.
 * ## Application Task
 * Depending on the selected application mode, it reads all the received data or 
 * sends the desired text message once per second.
 * @author MikroE Team
#include "board.h"
#include "log.h"
#include "irda2.h"

// Comment out the line below in order to switch the application mode to receiver

// Text message to send in the transmitter application mode
#define DEMO_TEXT_MESSAGE           "MIKROE - IrDA 2 click board\r\n\0"

static irda2_t irda2;
static log_t logger;

void application_init ( void ) 
    irda2_cfg_t irda2_cfg;
    log_cfg_t logger_cfg;

     * Logger initialization.
     * Default baud rate: 115200
     * Default log level: LOG_LEVEL_DEBUG
     * @note If USB_UART_RX and USB_UART_TX 
     * are defined as HAL_PIN_NC, you will 
     * need to define them manually for log to work. 
     * See @b LOG_MAP_USB_UART macro definition for detailed explanation.
    LOG_MAP_USB_UART( logger_cfg );
    log_init( &logger, &logger_cfg );
    log_info( &logger, " Application Init " );
    //  Click initialization.
    irda2_cfg_setup( &irda2_cfg );
    IRDA2_MAP_MIKROBUS( irda2_cfg, MIKROBUS_1 );
    if ( UART_ERROR == irda2_init( &irda2, &irda2_cfg ) ) 
        log_error( &logger, " Communication init." );
        for ( ; ; );
    irda2_default_cfg( &irda2 );
    irda2_reset( &irda2 );

    log_printf( &logger, " Application Mode: Transmitter\r\n" );
    log_printf( &logger, " Application Mode: Receiver\r\n" );
    log_info( &logger, " Application Task " );

void application_task ( void ) 
    irda2_generic_write( &irda2, DEMO_TEXT_MESSAGE, strlen( DEMO_TEXT_MESSAGE ) );
    log_printf( &logger, "%s", ( char * ) DEMO_TEXT_MESSAGE );
    Delay_ms( 1000 ); 
    uint8_t rx_byte = 0;
    if ( 1 == irda2_generic_read( &irda2, &rx_byte, 1 ) )
       log_printf( &logger, "%c", rx_byte );

int main ( void ) 
    application_init( );
    for ( ; ; ) 
        application_task( );

    return 0;

// ------------------------------------------------------------------------ END

Additional Support