Intermediate
30 min
0

Control your projects easily with CTHS15CIC05 and PIC18F26K22

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Button Power Click with EasyPIC v7

Published Dec 29, 2023

Click board™

Button Power Click

Development board

EasyPIC v7

Compiler

NECTO Studio

MCU

PIC18F26K22

Easily control device states using the intuitive POWER button, providing seamless on/off functionality tailored to your needs

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Hardware Overview

How does it work?

Button Power Click is based on the CTHS15CIC05ONOFF, a capacitive touch sensor display by VCC (Visual Communications Company). This sensor is an all-in-one solution, providing capacitive touch sensing in an appealing housing with the backlit power symbol icon on the top. A minimum number of pins is used on this device: only four pins are exposed to the user. Two more pins are used besides the power supply pins (VCC and GND). The touch detection is indicated by a HIGH logic level on the OUT pin of the CTHS15CIC05ONOFF sensor, while the IN pin is used as the power supply for two internal LEDs, which are connected in the common cathode configuration. The forward voltage of the LEDs is typically 3.2V. The OUT

pin of the sensor is routed to the INT pin of the mikroBUS™, while the IN pin of the sensor is routed to the PWM pin of the mikroBUS™. The power symbol icon on the top of the touch sensor is visible even when the backlight is off, thanks to the LEXAN™ polycarbonate film with an inverse print of the icon placed on top of the sensor. When the internal LEDs are turned ON, the light will pass through the translucent power symbol icon, resulting in a uniformly lit power symbol icon. An interesting lighting effect can be designed when touched by applying a PWM signal to the IN pin. The sensor IC, the sensing pad, and two integrated LEDs are enclosed in a small square casing, measuring 15mm by 15mm by 11mm. It forms a compact and robust touch button, which has

many advantages over a mechanical button: it is not subject to wear since there are no moving parts, it does not exhibit any bouncing or chattering effect, it is durable and resistant to weather elements, and more. However, it can’t be used to close an electrical circuit, only to produce a logic signal translated to appropriate action by the host MCU. The sensor can be operated even with wet hands or while using certain gloves. The touch sensor can also be placed behind a clear glass or a plastic layer, such as polycarbonate or acrylic, up to 3mm thick. Although the sensor will perform self-calibration after being powered, it is best to test its functionality in these cases if the position will be fixed.

Button Power Click top side image
Button Power Click bottom side image

Features overview

Development board

EasyPIC v7 is the seventh generation of PIC development boards specially designed to develop embedded applications rapidly. It supports a wide range of 8-bit PIC microcontrollers from Microchip and has a broad set of unique functions, such as a powerful onboard mikroProg programmer and In-Circuit debugger over USB-B. 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 v7 allows you to connect accessory boards, sensors, and custom electronics more efficiently than ever. Each part of

the EasyPIC v7 development board contains the components necessary for the most efficient operation of the same board. An integrated mikroProg, a fast USB 2.0 programmer with mikroICD hardware In-Circuit Debugger, offers many valuable programming/debugging options and seamless integration with the Mikroe software environment. Besides it also includes a clean and regulated power supply block 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-B (USB-B) 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 v7 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 v7 horizontal image

Microcontroller Overview

MCU Card / MCU

default

Architecture

PIC

MCU Memory (KB)

64

Silicon Vendor

Microchip

Pin count

28

RAM (Bytes)

3896

Used MCU Pins

mikroBUS™ mapper

NC
NC
AN
NC
NC
RST
NC
NC
CS
NC
NC
SCK
NC
NC
MISO
NC
NC
MOSI
Power Supply
3.3V
3.3V
Ground
GND
GND
Sensor LED Enable
RC1
PWM
Touch Detection
RB1
INT
NC
NC
TX
NC
NC
RX
NC
NC
SCL
NC
NC
SDA
NC
NC
5V
Ground
GND
GND
2

Take a closer look

Schematic

Button Power Click Schematic schematic

Step by step

Project assembly

EasyPIC v7 front image hardware assembly

Start by selecting your development board and Click board™. Begin with the EasyPIC v7 as your development board.

EasyPIC v7 front image hardware assembly
Rotary B 2 Click front image hardware assembly
MCU DIP 28 hardware assembly
EasyPIC v7 MB 2 - 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 Button Power Click driver.

Key functions:

  • buttonpower_pwm_stop - This function stops the PWM moudle output

  • buttonpower_pwm_start - This function starts the PWM moudle output

  • buttonpower_get_button_state - This function reads the digital signal from the INT pin which tells us whether the button has been pressed or not

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 main.c
 * @brief Button Power Click Example.
 *
 * # Description
 * This example showcases how to initialize and use the whole family of Button clicks. 
 * One library is used for every single one of them. They are simple touch detectors which send
 * a pressed/released signal and receive a PWM output which controls the backlight on the button.
 *
 * The demo application is composed of two sections :
 *
 * ## Application Init
 * This function initializes and configures the logger and click modules.
 *
 * ## Application Task
 * This example first increases the backlight on the button and then decreases the intensity of the backlight. When the button is touched,
 * reports the event in the console using UART communication.
 * 
 *
 * @author Nikola Peric
 *
 */

#include "board.h"
#include "log.h"
#include "buttonpower.h"

static buttonpower_t buttonpower;
static log_t logger;

void application_init ( void ) 
{
    log_cfg_t log_cfg;                   /**< Logger config object. */
    buttonpower_cfg_t buttonpower_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.

    buttonpower_cfg_setup( &buttonpower_cfg );
    BUTTONPOWER_MAP_MIKROBUS( buttonpower_cfg, MIKROBUS_1 );
    err_t init_flag  = buttonpower_init( &buttonpower, &buttonpower_cfg );
    if ( PWM_ERROR == init_flag ) 
    {
        log_error( &logger, " Application Init Error. " );
        log_info( &logger, " Please, run program again... " );

        for ( ; ; );
    }
    Delay_ms( 500 );
    
    buttonpower_pwm_start( &buttonpower );
    buttonpower_set_duty_cycle ( &buttonpower, 0.1 );

    log_info( &logger, " Application Task " );
}

void application_task ( void ) 
{
    static float duty_cycle;
    static uint8_t button_state;
    static uint8_t button_state_old;

    button_state = buttonpower_get_button_state( &buttonpower );
    
    if ( button_state && ( button_state != button_state_old ) ) 
    {
        log_printf( &logger, " <-- Button pressed --> \r\n" );
        for ( uint8_t n_cnt = 1; n_cnt <= 100; n_cnt++ )
        {
            duty_cycle = ( float ) n_cnt ;
            duty_cycle /= 100;
            buttonpower_set_duty_cycle( &buttonpower, duty_cycle );
            Delay_ms( 10 );
        }
        button_state_old = button_state;
    } 
    else if ( !button_state && ( button_state != button_state_old ) ) 
    {
        for ( uint8_t n_cnt = 100; n_cnt > 0; n_cnt-- )
        {
            duty_cycle = ( float ) n_cnt ;
            duty_cycle /= 100;
            buttonpower_set_duty_cycle( &buttonpower, duty_cycle );
            Delay_ms( 10 );
        }
        button_state_old = button_state;
    }
}

void main ( void )  
{
    application_init( );

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

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

Additional Support

Resources