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Create various touchpad adventures with MTCH6102 and PIC18LF45K22

Spark innovation at your fingertips

Touchpad Click with EasyPIC v7a

Published Aug 06, 2023

Click board™

Touchpad Click

Development board

EasyPIC v7a

Compiler

NECTO Studio

MCU

PIC18LF45K22

Incorporate capacitive touch sensing functions into your solution and set new standards

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Hardware Overview

How does it work?

Touchpad Click is based on the MTCH6102, a projected capacitive touch controller from Microchip. This controller utilizes up to fifteen I2C-controllable channels, offering a flexible touch-sensing solution for industry-leading applications such as remote controls, gaming devices, and trackpads. The MTCH6102 controller is very flexible, providing numerous gesture detection patterns such as single click, click and hold, double click, right/left/up/down swipe, and all with a hold function, all in one solution. A clearly defined field on the board's front side represents a touchpad area covered with a sheet of black plastic to

demonstrate the chip's support for cover layers (up to 3mm for plastic and 5mm for glass). This area is a matrix of conductive electrodes on the PCB, electrically isolated from each other, arranged as rows and columns of X and Y in a dimension of 25x17mm. An electrode consists of multiple diamond-shaped elements connected to the next with a conductive neck. Touchpad Click communicates with MCU using the standard I2C 2-Wire interface with a maximum clock frequency of 400kHz, fully adjustable through software registers. An additional ready signal, routed on the INT pin of the mikroBUS™ socket, is added,

indicating when the communication window is available with new data. Besides this pin, this Click board™ has a Reset feature routed to the RST pin on the mikroBUS™ socket, which, with a low logic level, puts the controller into a Reset state. This Click board™ can be operated only with a 3.3V logic voltage level. The board must perform appropriate logic voltage level conversion before using MCUs with different logic levels. Also, this Click board™ comes equipped with a library containing easy-to-use functions and an example code that can be used for further development.

Touchpad Click hardware overview image

Features overview

Development board

EasyPIC v7a is the seventh generation of PIC development boards specially designed for the needs of rapid development of embedded applications. It supports a wide range of 8-bit PIC microcontrollers from Microchip and has a broad set of unique functions, such as the first-ever embedded debugger/programmer over USB-C. The development board is well organized and designed so that the end-user has all the necessary elements in one place, such as switches, buttons, indicators, connectors, and others. With four different connectors for each port, EasyPIC v7a allows you to connect accessory boards, sensors, and custom electronics more efficiently than ever. Each part of the EasyPIC v7a development board

contains the components necessary for the most efficient operation of the same board. In addition to the advanced integrated CODEGRIP programmer/debugger module, which offers many valuable programming/debugging options and seamless integration with the Mikroe software environment, the board also includes a clean and regulated power supply module for the development board. It can use various external power sources, including an external 12V power supply, 7-23V AC or 9-32V DC via DC connector/screw terminals, and a power source via the USB Type-C (USB-C) connector. Communication options such as USB-UART and RS-232 are also included, alongside the well-

established mikroBUS™ standard, three display options (7-segment, graphical, and character-based LCD), and several different DIP sockets. These sockets cover a wide range of 8-bit PIC MCUs, from PIC10F, PIC12F, PIC16F, PIC16Enh, PIC18F, PIC18FJ, and PIC18FK families. EasyPIC v7a is an integral part of the Mikroe ecosystem for rapid development. Natively supported by Mikroe software tools, it covers many aspects of prototyping and development thanks to a considerable number of different Click boards™ (over a thousand boards), the number of which is growing every day.

EasyPIC v7a double side image

Microcontroller Overview

MCU Card / MCU

PIC18LF45K22

Architecture

PIC

MCU Memory (KB)

32

Silicon Vendor

Microchip

Pin count

40

RAM (Bytes)

1536

Used MCU Pins

mikroBUS™ mapper

NC
NC
AN
Reset
RE1
RST
NC
NC
CS
NC
NC
SCK
NC
NC
MISO
NC
NC
MOSI
Power Supply
3.3V
3.3V
Ground
GND
GND
NC
NC
PWM
Interrupt
RB0
INT
NC
NC
TX
NC
NC
RX
I2C Clock
RC3
SCL
I2C Data
RC4
SDA
NC
NC
5V
Ground
GND
GND
1

Take a closer look

Schematic

Touchpad Click Schematic schematic

Step by step

Project assembly

EasyPIC v7a front image hardware assembly

Start by selecting your development board and Click board™. Begin with the EasyPIC v7a as your development board.

EasyPIC v7a front image hardware assembly
Buck 22 Click front image hardware assembly
MCU DIP 40 hardware assembly
EasyPIC v7a MB 1 - upright/background hardware assembly
Necto image step 2 hardware assembly
Necto image step 3 hardware assembly
Necto image step 4 hardware assembly
NECTO Compiler Selection Step Image hardware assembly
NECTO Output Selection Step Image hardware assembly
Necto image step 6 hardware assembly
Necto DIP image step 7 hardware assembly
EasyPIC PRO v7a Display Selection Necto Step hardware assembly
Necto image step 9 hardware assembly
Necto image step 10 hardware assembly
Necto PreFlash Image hardware assembly

Track your results in real time

Application Output

After pressing the "FLASH" button on the left-side panel, it is necessary to open the UART terminal to display the achieved results. By clicking on the Tools icon in the right-hand panel, multiple different functions are displayed, among which is the UART Terminal. Click on the offered "UART Terminal" icon.

UART Application Output Step 1

Once the UART terminal is opened, the window takes on a new form. At the top of the tab are two buttons, one for adjusting the parameters of the UART terminal and the other for connecting the UART terminal. The tab's lower part is reserved for displaying the achieved results. Before connecting, the terminal has a Disconnected status, indicating that the terminal is not yet active. Before connecting, it is necessary to check the set parameters of the UART terminal. Click on the "OPTIONS" button.

UART Application Output Step 2

In the newly opened UART Terminal Options field, we check if the terminal settings are correct, such as the set port and the Baud rate of UART communication. If the data is not displayed properly, it is possible that the Baud rate value is not set correctly and needs to be adjusted to 115200. If all the parameters are set correctly, click on "CONFIGURE".

UART Application Output Step 3

The next step is to click on the "CONNECT" button, after which the terminal status changes from Disconnected to Connected in green, and the data is displayed in the Received data field.

UART Application Output Step 4

Software Support

Library Description

This library contains API for Touchpad Click driver.

Key functions:

  • touchpad_get_touch_coordinate - Get touch coordinate

  • touchpad_get_event_state - Get event state

  • touchpad_get_gesture_type - Gesture type

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 Touchpad Click example
 * 
 * # Description
 * Demo application shows reading of current event:
 *   - touch event (Touch Coordinates)
 *   - Gesture event (gesture type)
 *
 * The demo application is composed of two sections :
 * 
 * ## Application Init 
 * Configuring clicks and log objects.
 * Setting the click in the default configuration.
 * 
 * ## Application Task  
 * Reads every touch and gesture and this data logs to USBUART.
 * 
 * \author Katarina Perendic
 *
 */
// ------------------------------------------------------------------- INCLUDES

#include "board.h"
#include "log.h"
#include "touchpad.h"

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

static touchpad_t touchpad;
static log_t logger;

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

void application_init ( void )
{
    log_cfg_t log_cfg;
    touchpad_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.

    touchpad_cfg_setup( &cfg );
    TOUCHPAD_MAP_MIKROBUS( cfg, MIKROBUS_1 );
    touchpad_init( &touchpad, &cfg );

    touchpad_default_cfg( &touchpad );

    log_info( &logger, "---- Waiting for a new touch or gesure event ----" );
    Delay_ms( 500 );
}

void application_task ( void )
{
    uint8_t state;
    uint8_t gesture;
    touchpad_cord_t cord;

    //  Task implementation.

    Delay_ms( 50 );
    state = touchpad_get_event_state( &touchpad );
    if ( state == TOUCHPAD_EVENT_TOUCH )
    {
        touchpad_get_touch_coordinate( &touchpad, &cord );

        log_printf( &logger, "\r\n>> Touch coordinate <<" );
        log_printf( &logger, "\r\n>> ........... <<\r\n" );
        log_printf( &logger, "** X cord: %d \r\n** Y cord: %d \r\n", cord.x, cord.y );
        log_printf( &logger, ">> ........... <<\r\n" );
        Delay_ms( 50 );
    }
    else if ( state == TOUCHPAD_EVENT_GESTURE )
    {
        gesture = touchpad_get_gesture_type( &touchpad );
        switch( gesture )
        {
            case TOUCHPAD_GS_CLICK_AND_HOLD :
            {
                log_printf( &logger, "**Gesture type: Click and Hold\r\n" );
                break;
            }
            case TOUCHPAD_GS_DOUBLE_CLICK :
            {
                log_printf( &logger, "\r\n**Gesture type: Double Click\r\n" );
                break;
            }
            case TOUCHPAD_GS_SINGLE_CLICK :
            {
                log_printf( &logger, "\r\n**Gesture type: Single Click\r\n" );
                break;
            }
            case TOUCHPAD_GS_DOWN_SWIPE :
            {
                log_printf( &logger, "\r\n**Gesture type: Down Swipe\r\n" );
                break;
            }
            case TOUCHPAD_GS_DOWN_SWIPE_AND_HOLD :
            {
                log_printf( &logger, "\r\n**Gesture type: Down Swipe and Hold\r\n" );
                break;
            }
            case TOUCHPAD_GS_RIGHT_SWIPE :
            {
                log_printf( &logger, "\r\n**Gesture type: Right Swipe\r\n" );
                break;
            }
            case TOUCHPAD_GS_RIGHT_SWIPE_AND_HOLD :
            {
                log_printf( &logger, "\r\n**Gesture type: Right Swipe and Hold\r\n" );
                break;
            }
            case TOUCHPAD_GS_UP_SWIPE :
            {
                log_printf( &logger, "\r\n**Gesture type: Up Swipe\r\n" );
                break;
            }
            case TOUCHPAD_GS_UP_SWIPE_AND_HOLD :
            {
                log_printf( &logger, "\r\n**Gesture type: Up Swipe and Hold\r\n" );
                break;
            }
            case TOUCHPAD_GS_LEFT_SWIPE :
            {
                log_printf( &logger, "\r\n**Gesture type: Left Swipe\r\n" );
                break;
            }
            case TOUCHPAD_GS_LEFT_SWIPE_AND_HOLD :
            {
                log_printf( &logger, "\r\n**Gesture type: Left Swipe and Hold\r\n" );
                break;
            }
       }
    }
}

void main ( void )
{
    application_init( );

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


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

Additional Support

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