Line Follower Click

How does it work?

Line Follower Click is based on the QRE1113, a miniature reflective object sensor from ON Semiconductor. The array of the QRE1113 sensors is close to each other and points in the same direction, thus covering the more expansive space completely. The QRE1113 sensor is a no-surface contact sensing device and uses a phototransistor for output. By default, the sensor outputs a high logic level until they encounter a white surface which changes the output signal to a low logic state. Since there are five adjacent sensors, you can deduce the position or thickness of the white line from the combination of their outputs. The best results this Click board™ achieves are at a few millimeters from the surface to the sensors.

The Line Follower Click communicates with the host MCU by sending logical states to the corresponding pins of the mikroBUS™ socket. Each QRE1113 sensor has its own digital output; each routed through a single mikroBUS™ pin: U1, U2, U3, U4, and U5 (in place of default mikroBUS™ pins RST, AN, PWM, RX, and TX, respectively).

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. 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 Line Follower Click corresponds to the pinout on the mikroBUS™ socket (the latter shown in the two middle columns).

Notes	Pin					Pin	Notes
Output 2	U2	1	AN	PWM	16	U5	Output 5
Output 1	U1	2	RST	INT	15	NC
	NC	3	CS	RX	14	U4	Output4
	NC	4	SCK	TX	13	U3	Output 3
	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

Line Follower Click electrical specifications

Software Support

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

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

Library Description

This library contains API for Line Follower Click driver.

Key functions

• Get status of all pin function

Example Description

Line Follower click carries an array of five QRE1113 miniature reflective object sensors, reading staus of AN, RST, PWM, TX and RX pins and reading tracking data.

 void application_task ( void ) 
 { 
     linefollower_direction_t data_track; 

     linefollower_data_track ( &linefollower, &data_track ); 

     log_printf( &logger, " %ut%ut%ut%ut%urn",  
                 (uint16_t) data_track.u1,  
                 (uint16_t) data_track.u2,  
                 (uint16_t) data_track.u3,  
                 (uint16_t) data_track.u4,  
                 (uint16_t) data_track.u5); 

     Delay_ms ( 100 ); 
 }

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

Other Mikroe Libraries used in the example:

• MikroSDK.Board
• MikroSDK.Log
• Click.LineFollower

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 Mikroe compilers.

mikroSDK

This Click board™ is supported with mikroSDK – Mikroe 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.