IR Click

How does it work?

IR Click is based the TSOP38238, a miniaturized sensor for receiving the modulated signal of QEE113 IR emitting diode from Vishay Semiconductors. All Vishay IR receivers have the same circuit architecture consisting of a photodetector, pre-amplifier, and automatic gain control (ACG) to surpass ambient noise with transmitted signals. Tuned to a carrier frequency of 38kHz with a transmission distance of 45m and beam and viewing angle of 45 degrees, this Click board™ represents a compact and easy solution allowing you to control A/V equipment with IR remote controller.

The infrared signal generates an equivalent photocurrent in the integrated photo PIN diode. The DC part of the signal is blocked in the bias circuit, while the AC part is passed to a trans-impedance amplifier, followed by an automatic gain-control amplifier and an integrated bandpass filter. A comparator, an integrator, and a Schmitt Trigger stage perform the final signal conditioning. The blocks “Automatic Gain Control” and “Automatic Threshold Control” dynamically control the operating points and the threshold levels required to suppress noise from disturbance sources. The digital output signal has an active-low polarity and consists of an incoming optical burst envelope signal without the carrier frequency.

IR Click communicates with the target MCU via selectable GPIO lines. The selection can be made by positioning SMD jumpers to an appropriate position marked as GPIO or UART. The default configuration of this Click board™ allows transmission via the PWM pin of the mikroBUS™ socket and reception via the AN pin, while the other configuration allows communication using TX and RX pins.

This Click board™ can operate with both 3.3V and 5V logic voltage levels selected via the PWR SEL jumper. This way, it is allowed for both 3.3V and 5V capable MCUs to use the communication lines properly. However, the 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.

Specifications

Pinout diagram

This table shows how the pinout on IR Click corresponds to the pinout on the mikroBUS™ socket (the latter shown in the two middle columns).

Notes	Pin					Pin	Notes
Receive Signal	OUT	1	AN	PWM	16	IN	Transmit Signal
	NC	2	RST	INT	15	NC
	NC	3	CS	RX	14	TX	Transmit Signal
	NC	4	SCK	TX	13	RX	Receive Signal
	NC	5	MISO	SCL	12	NC
	NC	6	MOSI	SDA	11	NC
Power Supply	3.3V	7	3.3V	5V	10	5V	Power Supply
Ground	GND	8	GND	GND	9	GND	Ground

Onboard settings and indicators

IR Click electrical specifications

Software Support

We provide a library for the IR Click as well as a demo application (example), developed using MikroElektronika compilers. The demo can run on all the main MikroElektronika development boards.

Package can be downloaded/installed directly from NECTO Studio Package Manager(recommended way), downloaded from our LibStock™ or found on Mikroe github account.

Library Description

This library contains API for IR Click driver.

Key functions

• ir_get_an_state IR get AN pin state function.

• ir_nec_send_command IR NEC send data function.

• ir_nec_read_command IR NEC data reading function.

Example Description

This is an example that demonstrates the use of the IR Click board.

 void application_task ( void )  
 { 
     #ifdef IR_TRANSMITTER_MODE 
         log_printf( &logger, " Sending message." ); 

         for ( uint8_t cnt = 0; cnt < 8; cnt++ ) 
         { 
             ir_nec_send_command( &ir, 0x00, tx_data[ cnt ] ); 
             log_printf( &logger, "." ); 
             Delay_ms( 50 ); 
         } 

         log_printf( &logger, "rn Message sent! rn" ); 
         log_printf( &logger, "- - - - - - - - - - - - rn" ); 
         Delay_ms( 500 ); 
     #else 
         uint8_t arr; 
         char rx_data; 

         err_t err_flag = ir_nec_read_command ( &ir, &arr, &rx_data ); 

         if ( IR_OK == err_flag ) 
         { 
             log_printf( &logger, "%c", rx_data ); 
         } 
         else 
         { 
             log_printf( &logger, "Read ERROR! rn" ); 
         } 
         Delay_ms( 50 ); 
     #endif 
 }

The full application code, and ready to use projects can be installed directly from NECTO Studio Package Manager(recommended way), downloaded from our LibStock™ or found on Mikroe github account.

Other Mikroe Libraries used in the example:

• MikroSDK.Board
• MikroSDK.Log
• Click.IR

Additional notes and informations

Depending on the development board you are using, you may need USB UART click, USB UART 2 Click or RS232 Click to connect to your PC, for development systems with no UART to USB interface available on the board. UART terminal is available in all MikroElektronika compilers.

mikroSDK

This Click board™ is supported with mikroSDK - MikroElektronika Software Development Kit. To ensure proper operation of mikroSDK compliant Click board™ demo applications, mikroSDK should be downloaded from the LibStock and installed for the compiler you are using.

For more information about mikroSDK, visit the official page.