Maximize space and functionality by choosing our 16-in-1 button integration solution for your control needs
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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.
Features overview
Development board
Curiosity HPC, standing for Curiosity High Pin Count (HPC) development board, supports 28- and 40-pin 8-bit PIC MCUs specially designed by Microchip for the needs of rapid development of embedded applications. This board has two unique PDIP sockets, surrounded by dual-row expansion headers, allowing connectivity to all pins on the populated PIC MCUs. It also contains a powerful onboard PICkit™ (PKOB), eliminating the need for an external programming/debugging tool, two mikroBUS™ sockets for Click board™ connectivity, a USB connector, a set of indicator LEDs, push button switches and a variable potentiometer. All
these features allow you to combine the strength of Microchip and Mikroe and create custom electronic solutions more efficiently than ever. Each part of the Curiosity HPC development board contains the components necessary for the most efficient operation of the same board. An integrated onboard PICkit™ (PKOB) allows low-voltage programming and in-circuit debugging for all supported devices. When used with the MPLAB® X Integrated Development Environment (IDE, version 3.0 or higher) or MPLAB® Xpress IDE, in-circuit debugging allows users to run, modify, and troubleshoot their custom software and hardware
quickly without the need for additional debugging tools. Besides, it includes a clean and regulated power supply block for the development board via the USB Micro-B connector, alongside all communication methods that mikroBUS™ itself supports. Curiosity HPC development board allows you to create a new application in just a few steps. Natively supported by Microchip software tools, it covers many aspects of prototyping thanks to many number of different Click boards™ (over a thousand boards), the number of which is growing daily.
Microcontroller Overview
MCU Card / MCU

Architecture
PIC
MCU Memory (KB)
128
Silicon Vendor
Microchip
Pin count
40
RAM (Bytes)
3615
Used MCU Pins
mikroBUS™ mapper
Take a closer look
Click board™ Schematic

Step by step
Project assembly
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
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
* \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();
}
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
Additional Support
Resources
Category:Pushbutton/Switches

































