Beginner
10 min

Streamline the operation of complex systems with MC74HC165A and PIC32MZ1024EFH064

Streamline your control: 16 buttons, 1 masterpiece

4x4 Key Click with PIC32MZ clicker

Published Oct 17, 2023

Click board™

4x4 Key Click

Dev Board

PIC32MZ clicker

Compiler

NECTO Studio

MCU

PIC32MZ1024EFH064

Maximize space and functionality by choosing our 16-in-1 button integration solution for your control needs

A

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Hardware Overview

How does it work?

4x4 Key Click is based on 16 buttons with debounce circuits and two MC74HC165A, 8-bit parallel-in/serial-out shift registers from ON Semiconductor. The rightmost column of the keyboard is marked with letters from A to D, while the other 12 buttons are marked like a telephone keypad, so it is easy to implement this 4x4 Click board to any design. The 16-button output lines go straight to the parallel data inputs of the two shift registers connected in a serial (daisy) chain, thus

occupying fewer pins on the host MCU. The shift registers allow you to press all 16 buttons simultaneously, and each will be registered. The 4X4 Click board uses an SPI serial interface to communicate with the host MCU over the mikroBUS™ socket. In this case, the SPI interface saves as many IO pins of the MCU as possible from 16 buttons using shift registers. The Clock Enable pins of the shift registers are not user-configurable and are tied LOW; thus, shift registers are always

enabled. 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.

4x4 Key Click hardware overview image

Features overview

Development board

PIC32MZ Clicker is a compact starter development board that brings the flexibility of add-on Click boards™ to your favorite microcontroller, making it a perfect starter kit for implementing your ideas. It comes with an onboard 32-bit PIC32MZ microcontroller with FPU from Microchip, a USB connector, LED indicators, buttons, a mikroProg connector, and a header for interfacing with external electronics. Thanks to its compact design with clear and easy-recognizable silkscreen markings, it provides a fluid and immersive working experience, allowing access anywhere and under

any circumstances. Each part of the PIC32MZ Clicker development kit contains the components necessary for the most efficient operation of the same board. In addition to the possibility of choosing the PIC32MZ Clicker programming method, using USB HID mikroBootloader, or through an external mikroProg connector for PIC, dsPIC, or PIC32 programmer, the Clicker board also includes a clean and regulated power supply module for the development kit. The USB Micro-B connection can provide up to 500mA of current, which is more than enough to operate all onboard

and additional modules. All communication methods that mikroBUS™ itself supports are on this board, including the well-established mikroBUS™ socket, reset button, and several buttons and LED indicators. PIC32MZ Clicker is an integral part of the Mikroe ecosystem, allowing you to create a new application in minutes. Natively supported by Mikroe software tools, it covers many aspects of prototyping thanks to a considerable number of different Click boards™ (over a thousand boards), the number of which is growing every day.

PIC32MZ clicker double side image

Microcontroller Overview

MCU Card / MCU

default

Architecture

PIC32

MCU Memory (KB)

1024

Silicon Vendor

Microchip

Pin count

64

RAM (Bytes)

524288

Used MCU Pins

mikroBUS™ mapper

NC
NC
AN
NC
NC
RST
SPI Chip Select
RG9
CS
SPI Clock
RG6
SCK
SPI Data OUT
RG7
MISO
SPI Data IN
RG8
MOSI
Power Supply
3.3V
3.3V
Ground
GND
GND
NC
NC
PWM
NC
NC
INT
NC
NC
TX
NC
NC
RX
NC
NC
SCL
NC
NC
SDA
Power Supply
5V
5V
Ground
GND
GND
1

Take a closer look

Schematic

4x4 Key Click Schematic schematic

Step by step

Project assembly

PIC32MZ clicker front image hardware assembly

Start by selecting your development board and Click board™. Begin with the PIC32MZ clicker as your development board.

PIC32MZ clicker front image hardware assembly
Thermo 26 Click front image hardware assembly
Prog-cut hardware assembly
Micro B Connector clicker - 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
Flip&Click PIC32MZ 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 via Debug Mode

1. Once the code example is loaded, pressing the "DEBUG" button initiates the build process, programs it on the created setup, and enters Debug mode.

2. After the programming is completed, a header with buttons for various actions within the IDE becomes visible. Clicking the green "PLAY" button starts reading the results achieved with the Click board™. The achieved results are displayed in the Application Output tab.

DEBUG_Application_Output

Software Support

Library Description

This library contains API for 4x4 Key Click driver.

Key functions:

  • c4x4key_get_data - Get 16-bit data function.

  • c4x4key_get_btn_position - Get position pressed button function.

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 
 * \brief 4x4Key Click example
 * 
 * # Description
 * The library covers all the necessary functions to control the 4x4 Key Click.
 * 4x4 Key click communicates with the target board via SPI interface. 
 * This library contains drivers for reading data from a sensor and get 
 * the position of the pressed button.
 *
 * The demo application is composed of two sections :
 * 
 * ## Application Init 
 * Configuring clicks and log objects.
 * 
 * ## Application Task  
 * This is a example which demonstrates the use of 4x4 Key Click board.
 * Detects and logs whether any of the buttons is pressed.
 * Results are being sent to the Usart Terminal
 * where you can track their changes.
 * All data logs on usb uart when the button is triggered.
 * 
 * \author Nenad Filipovic
 *
 */
// ------------------------------------------------------------------- INCLUDES

#include "board.h"
#include "log.h"
#include "c4x4key.h"

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

static c4x4key_t c4x4key;
static log_t logger;

static uint16_t btn_data_old;

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

void application_init ( void )
{
    log_cfg_t log_cfg;
    c4x4key_cfg_t 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( log_cfg );
    log_init( &logger, &log_cfg );
    log_info( &logger, "---- Application Init ----" );

    //  Click initialization.

    c4x4key_cfg_setup( &cfg );
    C4X4KEY_MAP_MIKROBUS( cfg, MIKROBUS_1 );
    c4x4key_init( &c4x4key, &cfg );
    
    btn_data_old = 0;
    
    log_printf( &logger, "   4x4 Key Click\r\n" );
    log_printf( &logger, "--------------------\r\n" );
    log_printf( &logger, "  Press any button\r\n" );
    log_printf( &logger, "--------------------\r\n" );
}

void application_task ( void )
{
    uint16_t btn_data;
    
    btn_data = c4x4key_get_data( &c4x4key );

    if ( btn_data_old != btn_data )
    {
        if ( btn_data == C4X4KEY_BUTTON_0 )
        {
            log_printf( &logger, "         0\r\n" );
        }
        
        if ( btn_data == C4X4KEY_BUTTON_1 )
        {
            log_printf( &logger, "         1\r\n" );
        }
        
        if ( btn_data == C4X4KEY_BUTTON_2 )
        {
            log_printf( &logger, "         2\r\n" );
        }
        
        if ( btn_data == C4X4KEY_BUTTON_3 )
        {
            log_printf( &logger, "         3\r\n" );
        }
        
        if ( btn_data == C4X4KEY_BUTTON_4 )
        {
            log_printf( &logger, "         4\r\n" );
        }
        
        if ( btn_data == C4X4KEY_BUTTON_5 )
        {
            log_printf( &logger, "         5\r\n" );
        }
        
        if ( btn_data == C4X4KEY_BUTTON_6 )
        {
            log_printf( &logger, "         6\r\n" );
        }
        
        if ( btn_data == C4X4KEY_BUTTON_7 )
        {
            log_printf( &logger, "         7\r\n" );
        }
        
        if ( btn_data == C4X4KEY_BUTTON_8 )
        {
            log_printf( &logger, "         8\r\n" );
        }
        
        if ( btn_data == C4X4KEY_BUTTON_9 )
        {
            log_printf( &logger, "         9\r\n" );
        }
        
        if ( btn_data == C4X4KEY_BUTTON_A )
        {
            log_printf( &logger, "         A\r\n" );
        }
        
        if ( btn_data == C4X4KEY_BUTTON_B )
        {
            log_printf( &logger, "         B\r\n" );
        }
        
        if ( btn_data == C4X4KEY_BUTTON_C )
        {
            log_printf( &logger, "         C\r\n" );
        }
        
        if ( btn_data == C4X4KEY_BUTTON_D )
        {
            log_printf( &logger, "         D\r\n" );
        }
        
        if ( btn_data == C4X4KEY_BUTTON_STAR )
        {
            log_printf( &logger, "         *\r\n" );
        }
        
        if ( btn_data == C4X4KEY_BUTTON_HASH )
        {
            log_printf( &logger, "         #\r\n" );
        }

        btn_data_old = btn_data;
    }
    Delay_10ms();
}

void main ( void )
{
    application_init( );

    for ( ; ; )
    {
        application_task( );
    }
}


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

Additional Support

Resources

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