Beginner
10 min

Achieve precise control and confirm actions within industrial settings using the combination of three TL3215 series tactile switches and PIC32MZ2048EFM100

Straightforward and effective tactile switch integration

Button 3 Click with Curiosity PIC32 MZ EF

Published Aug 06, 2024

Click board™

Button 3 Click

Dev. board

Curiosity PIC32 MZ EF

Compiler

NECTO Studio

MCU

PIC32MZ2048EFM100

Control actions with reliable tactile input in consumer electronics, industrial equipment, and automotive systems via high-performance tactile switches

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Hardware Overview

How does it work?

Button 3 Click is based on three tactile switches, members of the TL3215 series of tactile switches from E-Switch. Each specific switch features several key characteristics, denoted by its part number TL3215AF160BQ/TL3215AF160RQ/TL3215AF160GQ. The 'TL' in the part number indicates it belongs to the TL series, known for its high reliability and consistent performance. The '3215' model is a testament to its robust construction and design. It includes an actuator option ('A') with a 2mm actuator, ensuring precise and responsive operation. The 'F160' denotes an actuation force of 160gf, providing a balanced tactile feedback that is neither too hard nor too soft, thus preventing accidental presses while remaining user-friendly. The 'B/R/G' indicates the blue/red/green color of the switch, making it easily identifiable, while the 'Q' signifies the use of silver contact material, known for its excellent conductivity and durability. Regarding specifications, these switches have an impressive electrical rating of 50mA at 12VDC, and their electrical and mechanical life is

rated at 1,000,000 cycles, ensuring longevity and reliability in various applications. Initially, the contact resistance is a maximum of 100mΩ, while the insulation resistance stands at 100MΩ at 500VDC, highlighting its excellent electrical isolation properties. The switches also have a dielectric strength of 250VAC for 1 minute and operate efficiently from -40°C to 85°C. The contact arrangement is single-pole single-throw (SPST), providing straightforward switching functionality. Additionally, the integrated LED in this version operates at a forward current of 20mA with a typical forward voltage of 3V at 20mA. It delivers a typical luminous intensity of 100mcd, ensuring clear visibility of the switch's status. This Click board™ is designed in a unique format supporting the newly introduced MIKROE feature called "Click Snap." Unlike the standardized version of Click boards, this feature allows the main sensor area to become movable by breaking the PCB, opening up many new possibilities for implementation. Thanks to the Snap feature, the switches can operate autonomously by accessing their signals directly on

the pins marked 1-8. Additionally, the Snap part includes a specified and fixed screw hole position, enabling users to secure the Snap board in their desired location. Button 3 Click communicates with the host MCU via the TCA6408A port expander using the I2C interface. This port expander allows control of all buttons and their control signals, including a signal dedicated to detecting button presses (providing an interrupt signal to the host MCU (INT) whenever the tactile switch is activated) and the signal that controls the LED on the TL3215. In addition to the I2C interface pins, the port expander also uses a reset (RST) pin and a jumper for I2C address selection, ADDR SEL. This Click board™ can operate with either 3.3V or 5V logic voltage levels selected via the VCC 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.

Button 3 Click hardware overview image

Features overview

Development board

Curiosity PIC32 MZ EF development board is a fully integrated 32-bit development platform featuring the high-performance PIC32MZ EF Series (PIC32MZ2048EFM) that has a 2MB Flash, 512KB RAM, integrated FPU, Crypto accelerator, and excellent connectivity options. It includes an integrated programmer and debugger, requiring no additional hardware. Users can expand

functionality through MIKROE mikroBUS™ Click™ adapter boards, add Ethernet connectivity with the Microchip PHY daughter board, add WiFi connectivity capability using the Microchip expansions boards, and add audio input and output capability with Microchip audio daughter boards. These boards are fully integrated into PIC32’s powerful software framework, MPLAB Harmony,

which provides a flexible and modular interface to application development a rich set of inter-operable software stacks (TCP-IP, USB), and easy-to-use features. The Curiosity PIC32 MZ EF development board offers expansion capabilities making it an excellent choice for a rapid prototyping board in Connectivity, IOT, and general-purpose applications.

Curiosity PIC32MZ EF double side image

Microcontroller Overview

MCU Card / MCU

default

Architecture

PIC32

MCU Memory (KB)

2048

Silicon Vendor

Microchip

Pin count

100

RAM (Bytes)

524288

Used MCU Pins

mikroBUS™ mapper

NC
NC
AN
Reset
RA9
RST
ID COMM
RPD4
CS
NC
NC
SCK
NC
NC
MISO
NC
NC
MOSI
Power Supply
3.3V
3.3V
Ground
GND
GND
NC
NC
PWM
Interrupt
RF13
INT
NC
NC
TX
NC
NC
RX
I2C Clock
RPA14
SCL
I2C Data
RPA15
SDA
Power Supply
5V
5V
Ground
GND
GND
1

Take a closer look

Click board™ Schematic

Button 3 Click Schematic schematic

Step by step

Project assembly

Curiosity PIC32MZ EF front image hardware assembly

Start by selecting your development board and Click board™. Begin with the Curiosity PIC32 MZ EF as your development board.

Curiosity PIC32MZ EF front image hardware assembly
GNSS2 Click front image hardware assembly
Prog-cut hardware assembly
GNSS2 Click complete accessories setup image hardware assembly
Board mapper by product7 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
Curiosity PIC32 MZ EF 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

Software Support

Library Description

This library contains API for Button 3 Click driver.

Key functions:

  • button3_toggle_red_led - This function toggles the red button LED by toggling the RK pin logic state.

  • button3_toggle_green_led - This function toggles the green button LED by toggling the GK pin logic state.

  • button3_toggle_blue_led - This function toggles the blue button LED by toggling the BK pin logic state.

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 Button 3 Click example
 *
 * # Description
 * This example demonstrates the use of Button 3 Click board by toggling a button
 * LED and its switch state on a button press.
 *
 * The demo application is composed of two sections :
 *
 * ## Application Init
 * Initializes the driver and performs the Click default configuration.
 *
 * ## Application Task
 * Toggles a button LED and its switch state on a button press and displays the state
 * on the USB UART.
 *
 * @author Stefan Filipovic
 *
 */

#include "board.h"
#include "log.h"
#include "button3.h"

static button3_t button3;
static log_t logger;

void application_init ( void ) 
{
    log_cfg_t log_cfg;  /**< Logger config object. */
    button3_cfg_t button3_cfg;  /**< Click config object. */

    /** 
     * 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.
    button3_cfg_setup( &button3_cfg );
    BUTTON3_MAP_MIKROBUS( button3_cfg, MIKROBUS_1 );
    if ( I2C_MASTER_ERROR == button3_init( &button3, &button3_cfg ) ) 
    {
        log_error( &logger, " Communication init." );
        for ( ; ; );
    }
    
    if ( BUTTON3_ERROR == button3_default_cfg ( &button3 ) )
    {
        log_error( &logger, " Default configuration." );
        for ( ; ; );
    }
    
    log_info( &logger, " Application Task " );
    log_printf ( &logger, " Press button to change switch state\r\n\n" );
    log_printf ( &logger, " RED SWITCH OFF\r\n\n" );
    log_printf ( &logger, " GREEN SWITCH OFF\r\n\n" );
    log_printf ( &logger, " BLUE SWITCH OFF\r\n\n" );
}

void application_task ( void ) 
{
    static uint8_t red_switch_state = BUTTON3_SWITCH_OFF;
    static uint8_t green_switch_state = BUTTON3_SWITCH_OFF;
    static uint8_t blue_switch_state = BUTTON3_SWITCH_OFF;
    uint8_t switch_state = BUTTON3_SWITCH_OFF;

    if ( BUTTON3_PIN_STATE_LOW == button3_get_int_pin ( &button3 ) )
    {
        if ( ( BUTTON3_OK == button3_get_red_button ( &button3, &switch_state ) ) && 
             ( BUTTON3_BUTTON_PRESSED == switch_state ) )
        {
            button3_toggle_red_led ( &button3 );
            red_switch_state ^= BUTTON3_SWITCH_ON;
            if ( BUTTON3_SWITCH_ON == red_switch_state )
            {
                log_printf ( &logger, " RED SWITCH ON\r\n\n" );
            }
            else
            {
                log_printf ( &logger, " RED SWITCH OFF\r\n\n" );
            }
        }
        if ( ( BUTTON3_OK == button3_get_green_button ( &button3, &switch_state ) ) && 
             ( BUTTON3_BUTTON_PRESSED == switch_state ) )
        {
            button3_toggle_green_led ( &button3 );
            green_switch_state ^= BUTTON3_SWITCH_ON;
            if ( BUTTON3_SWITCH_ON == green_switch_state )
            {
                log_printf ( &logger, " GREEN SWITCH ON\r\n\n" );
            }
            else
            {
                log_printf ( &logger, " GREEN SWITCH OFF\r\n\n" );
            }
        }
        if ( ( BUTTON3_OK == button3_get_blue_button ( &button3, &switch_state ) ) && 
             ( BUTTON3_BUTTON_PRESSED == switch_state ) )
        {
            button3_toggle_blue_led ( &button3 );
            blue_switch_state ^= BUTTON3_SWITCH_ON;
            if ( BUTTON3_SWITCH_ON == blue_switch_state )
            {
                log_printf ( &logger, " BLUE SWITCH ON\r\n\n" );
            }
            else
            {
                log_printf ( &logger, " BLUE SWITCH OFF\r\n\n" );
            }
        }
        Delay_ms ( 100 );
    }
}

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

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