Matrix R Click

How does it work?

Matrix R Click is based on two MAX7219, serially interfaced, 8-digit LED display drivers from Analog Devices. The MAX7219 over 10MHz serial interface is capable of addressing each LED of the two onboard red 5×7 matrices individually or all at the same time. It has digital and analog brightness control, blanked display on Power-Up sequence, low-power shutdown with data retained, and more features. It also includes a BCD code-B decoder, multiplex scan circuitry, segment and digit drivers, and an 8×8 static RAM that stores each data. Users can get four-character displays if they double up on a board with two adjacent mikroBUS™ sockets, such as Fusion, Clicker 2, or Flip&Click.

The Matrix R Click uses an SPI serial interface to communicate to the host microcontroller, with speeds of up to 10MHz. Each MAX7219’s chip select pin is connected to the appropriate pin on the mikroBUS™ socket. The MAX7219 that controls the left display is connected to the pin labeled CSL, while the right is connected to the pin labeled CSR. Serial data is loaded into the shift register while the corresponding chip select pin is in a low logic state. The peak segment current is set to around 40mA with an external resistor. The display’s brightness can be controlled by the internal PWM by the software.

This Click board™ can be operated only with a 5V logic voltage level. The board must perform appropriate logic voltage level conversion before using MCUs with different logic levels. However, the Click board™ comes equipped with a library containing 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 Matrix R Click corresponds to the pinout on the mikroBUS™ socket (the latter shown in the two middle columns).

Notes	Pin					Pin	Notes
Right Display SPI Chip Select	CSR	1	AN	PWM	16	NC
	NC	2	RST	INT	15	NC
Left Display SPI Chip Select	CSL	3	CS	RX	14	NC
SPI Clock	SCK	4	SCK	TX	13	NC
SPI Data OUT	SDO	5	MISO	SCL	12	NC
SPI Data IN	SDI	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

Matrix R Click electrical specifications

Software Support

We provide a library for the Matrix R 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 Matrix R Click driver.

Key functions

• matrixr_display_characters This function displays the specified characters on the L/R segments of the click.

• matrixr_set_csn_high This function sets the CSN pin output to high.

• matrixr_set_csn_low This function sets the CSN pin output to low.

Example Description

This example showcases how to prepare the logger and click modules for use and how to display ASCII characters on both of the LED segments of the click.

 void application_task ( ) { 

     matrixr_display_characters( &matrixr, ' ', 'M' ); 
     Delay_ms( 1000 ); 
     matrixr_display_characters( &matrixr, 'M', 'i' ); 
     Delay_ms( 1000 ); 
     matrixr_display_characters( &matrixr, 'i', 'k' ); 
     Delay_ms( 1000 ); 
     matrixr_display_characters( &matrixr, 'k', 'r' ); 
     Delay_ms( 1000); 
     matrixr_display_characters( &matrixr, 'r', 'o' ); 
     Delay_ms( 1000 ); 
     matrixr_display_characters( &matrixr, 'o', 'E' ); 
     Delay_ms( 1000 ); 
     matrixr_display_characters( &matrixr, 'E', 'l' ); 
     Delay_ms( 1000 ); 
     matrixr_display_characters( &matrixr, 'l', 'e' ); 
     Delay_ms( 1000 ); 
     matrixr_display_characters( &matrixr, 'e', 'k' ); 
     Delay_ms( 1000 ); 
     matrixr_display_characters( &matrixr, 'k', 't' ); 
     Delay_ms( 1000 ); 
     matrixr_display_characters( &matrixr, 't', 'r' ); 
     Delay_ms( 1000 ); 
     matrixr_display_characters( &matrixr, 'r', 'o' ); 
     Delay_ms( 1000 ); 
     matrixr_display_characters( &matrixr, 'o', 'n' ); 
     Delay_ms( 1000 ); 
     matrixr_display_characters( &matrixr, 'n', 'i' ); 
     Delay_ms( 1000 ); 
     matrixr_display_characters( &matrixr, 'i', 'k' ); 
     Delay_ms( 1000 ); 
     matrixr_display_characters( &matrixr, 'k', 'a' ); 
     Delay_ms( 100 ); 
     matrixr_display_characters( &matrixr, 'a', ' ' ); 
     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.MatrixR

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.