Achieve pixel perfection with SZ420757N and ATmega1284

Visualize, customize, amaze: 7x10 red dot magic!

Published Jul 09, 2024

Click board™

7x10 R Click

Dev. board

EasyAVR v8

Compiler

NECTO Studio

MCU

ATmega1284

Our 7x10 red LED dot matrix display solution offers a versatile canvas for visual creativity, making it perfect for applications ranging from scrolling messages to pixel art and real-time data visualization

Hardware Overview

How does it work?

7x10 R Click is based on two SZ420757N, red LED dot matrix modules from Wuxi Ark. A single LED matrix module is composed of 35 LED elements grouped in rows and columns. The LED elements in one row have their cathodes connected and routed to a single-row pin. The LED elements in one column have their anodes connected and routed to a single-column pin. Multiplexed like this, modules have a fairly low number of pins (12 per module), making them suitable to be driven by shift registers and a decade of counter ICs. The driver circuit consists of two 74HC595 - 8bit, serial input - parallel output shift registers, one CD4017 - a Jonson topology decade counter with ten outputs, and one ULN2003A - an IC with seven integrated Darlington transistor pairs, all

chips produced by Texas Instruments. The shift registers are used to polarize the anodes on the columns of the LED displays. To complete the LED's current path, their cathodes must be connected to the ground. This is where the CD4017 and ULN2003 ICs are used. The ULN2003 IC drives rows of the dot matrix displays by sinking the current on the active row. To activate one of the seven input channels of the ULN2003 IC, the CD4017 decade counter IC is used. The design of the decade counter allows only one row to be active at a time. So, to see the complete picture on an LED matrix, the row scanning has to be fast enough so that the effect called persistent vision takes place. It produces an illusion of a complete image, even if only one row is seen at a time -

because the human eye cannot detect very fast changes in light. 7x10 R Click uses a 4-Wire SPI serial interface of the 74HC595 shift registers to communicate with the host MCU. The shift registers are chained together and can be reset over the RST pin. The clock and the reset inputs of the CD4017 are controlled by the RC and RR pins. 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.

Features overview

Development board

EasyAVR v8 is a development board designed to rapidly develop embedded applications based on 8-bit AVR microcontrollers (MCUs). Redesigned from the ground up, EasyAVR v8 offers a familiar set of standard features, as well as some new and unique features standard for the 8th generation of development boards: programming and debugging over the WiFi network, connectivity provided by USB-C connectors, support for a wide range of different MCUs, and more. The development board is designed so that the developer has everything that might be needed for the application development, following the Swiss Army knife concept: a highly advanced programmer/debugger module, a reliable power supply module, and a USB-UART connectivity option. EasyAVR v8 board offers several different DIP sockets, covering a wide range of 8-bit AVR MCUs, from the smallest

AVR MCU devices with only eight pins, all the way up to 40-pin "giants". The development board supports the well-established mikroBUS™ connectivity standard, offering five mikroBUS™ sockets, allowing access to a huge base of Click boards™. EasyAVR v8 offers two display options, allowing even the basic 8-bit AVR MCU devices to utilize them and display graphical or textual content. One of them is the 1x20 graphical display connector, compatible with the familiar Graphical Liquid Crystal Display (GLCD) based on the KS108 (or compatible) display driver, and EasyTFT board that contains TFT Color Display MI0283QT-9A, which is driven by ILI9341 display controller, capable of showing advanced graphical content. The other option is the 2x16 character LCD module, a four-bit display module with an embedded character-based display controller. It

requires minimal processing power from the host MCU for its operation. There is a wide range of useful interactive options at the disposal: high-quality buttons with selectable press levels, LEDs, pull-up/pulldown DIP switches, and more. All these features are packed on a single development board, which uses innovative manufacturing technologies, delivering a fluid and immersive working experience. The EasyAVR v8 development board is also integral to the MIKROE rapid development ecosystem. Natively supported by the MIKROE Software toolchain, backed up by hundreds of different Click board™ designs with their number growing daily, it covers many different prototyping and development aspects, thus saving precious development time.

Microcontroller Overview

MCU Card / MCU

Architecture

AVR

MCU Memory (KB)

128

Silicon Vendor

Microchip

Pin count

RAM (Bytes)

16384

Used MCU Pins

mikroBUS™ mapper

CD4017 Clock

PA7

74HC595 Reset

PA4

RST

74HC595 Latch

PB4

SPI Clock

PB7

SCK

SPI Data OUT

PB6

MISO

SPI Data IN

PB5

MOSI

Power Supply

3.3V

Ground

GND

CD4017 Reset

PD4

PWM

INT

SCL

SDA

Power Supply

Ground

GND

Take a closer look

Click board™ Schematic

Step by step

Project assembly

EasyAVR v8 front image hardware assembly

Start by selecting your development board and Click board™. Begin with the EasyAVR v8 as your development board.

NECTO Output Selection Step Image hardware assembly

In the advanced settings, pay special attention to the Redirect standard output field. By default, it is set to Application output as the method of displaying final results. To show results via a UART terminal, select the “UART” option in that field and click the “SAVE” button. You will be returned to the Compiler field, and now you can move on to the next step by pressing the “NEXT” button.

Stepper 24 Click front image hardware assembly

Stepper 24 Click complete accessories setup image hardware assembly

EasyAVR v8 Access DIP MB 1 - upright/background hardware assembly

NECTO Compiler Selection Step Image hardware assembly

Necto DIP image step 7 hardware assembly

EasyPIC PRO v7a Display Selection Necto Step hardware assembly

Track your results in real time

Application Output

1. Application Output - In Debug mode, the 'Application Output' window enables real-time data monitoring, offering direct insight into execution results. Ensure proper data display by configuring the environment correctly using the provided tutorial.

2. UART Terminal - Use the UART Terminal to monitor data transmission via a USB to UART converter, allowing direct communication between the Click board™ and your development system. Configure the baud rate and other serial settings according to your project's requirements to ensure proper functionality. For step-by-step setup instructions, refer to the provided tutorial.

3. Plot Output - The Plot feature offers a powerful way to visualize real-time sensor data, enabling trend analysis, debugging, and comparison of multiple data points. To set it up correctly, follow the provided tutorial, which includes a step-by-step example of using the Plot feature to display Click board™ readings. To use the Plot feature in your code, use the function: plot(*insert_graph_name*, variable_name);. This is a general format, and it is up to the user to replace 'insert_graph_name' with the actual graph name and 'variable_name' with the parameter to be displayed.

Software Support

Library Description

This library contains API for 7x10 R Click driver.

Key functions:

c7x10r_draw_pixel - Drawing the pixel on the display
c7x10r_draw_char - Drawing the character on the display
c7x10r_draw_number - Drawing the number on the display

Open Source

Code example

The complete application code and a ready-to-use project are available through the NECTO Studio Package Manager for direct installation in the NECTO Studio. The application code can also be found on the MIKROE GitHub account.

/*!
 * @file main.c
 * @brief c7x10R Click example
 *
 * # Description
 * This demo example shows a drawing of pixels, characters and a number on the screen.
 *
 * The demo application is composed of two sections :
 *
 * ## Application Init
 * Configuring the Click board.
 *
 * ## Application Task
 * Draws characters, numbers, and pixels to the display.
 *
 * @author Jelena Milosavljevic
 *
 */

#include "board.h"
#include "c7x10r.h"

// ------------------------------------------------------------------ VARIABLES

static c7x10r_t c7x10r;

// ------------------------------------------------------ APPLICATION FUNCTIONS

void application_init ( void ) {
    
    c7x10r_cfg_t c7x10r_cfg;  /**< Click config object. */

    //  Click initialization.
    
    c7x10r_cfg_setup( &c7x10r_cfg );
    C7X10R_MAP_MIKROBUS( c7x10r_cfg, MIKROBUS_1 );
    c7x10r_init( &c7x10r, &c7x10r_cfg );
}

void application_task ( void ) {
    
    c7x10r_pixel_t pixel;
    uint8_t cnt;
    uint8_t cnt_x;
    uint8_t cnt_y;
    
    // CHAR PROCEDURE
    
    for ( cnt = 'A'; cnt < 'Z'; cnt+=2 ) {
        
        c7x10r_draw_char( &c7x10r, cnt, C7X10R_DISPLAY_LEFT, C7X10R_DISPLAY_DELAY_50MS );
        c7x10r_draw_char( &c7x10r, cnt + 1, C7X10R_DISPLAY_RIGHT | C7X10R_DISPLAY_REFRESH, C7X10R_DISPLAY_DELAY_50MS );
       
        Delay_ms ( 1000 );
    }

    // COUNTER PROCEDURE
    
    for ( cnt = 0; cnt < 15; cnt++ ) {
        
        c7x10r_draw_number( &c7x10r, cnt, C7X10R_DISPLAY_DELAY_50MS );
        
        Delay_ms ( 500 );
    }
    
    // PIXELS PROCEDURE
    
    for ( cnt_x = 0; cnt_x <= 7; cnt_x++ ) {
        
        for ( cnt_y = 0; cnt_y <= 10; cnt_y++ ) {
            
            pixel.cord_x = cnt_x;
            pixel.cord_y = cnt_y;
            c7x10r_draw_pixel( &c7x10r, &pixel, C7X10R_DISPLAY_PIXEL_STORAGE, C7X10R_DISPLAY_DELAY_20MS );

            pixel.cord_x = cnt_x;
            pixel.cord_y = cnt_y + 1;
            c7x10r_draw_pixel( &c7x10r, &pixel, C7X10R_DISPLAY_PIXEL_REFRESH, C7X10R_DISPLAY_DELAY_20MS );
        }
    }
}

int main ( void ) 
{
    /* Do not remove this line or clock might not be set correctly. */
    #ifdef PREINIT_SUPPORTED
    preinit();
    #endif
    
    application_init( );
    
    for ( ; ; ) 
    {
        application_task( );
    }

    return 0;
}

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