Beginner
10 min

Achieve precise and natural control using COM-09032 and PIC18LF46K40

Level up your HMI experience

THUMBSTICK Click with EasyPIC v8

Published Jun 20, 2023

Click board™

THUMBSTICK Click

Dev. board

EasyPIC v8

Compiler

NECTO Studio

MCU

PIC18LF46K40

Achieve precise analog control for gaming consoles and controllers, enhancing the gameplay experience, or applications that require accurate control inputs, such as robotics or drone navigation systems

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Hardware Overview

How does it work?

Thumbstick Click is based on the COM-09032, a high-quality 2-axis analog-type thumbstick from Sparkfun. This type of thumbstick has a self-centering feature (spring return) that allows it to center itself the moment when you release it. It also contains a comfortable cup-type black knob/cap, which gives the feel of a thumbstick, making it very similar to the 'analog' joysticks used on joypads on popular gaming consoles like PSP joysticks. This feature makes it suitable for numerous applications as a human-machine interface. It comprises two 10kΩ potentiometers, one for up/down and another for left/right direction, used as dual adjustable voltage dividers providing 2-axis analog input in a control stick form. With the thumbstick fully

assembled and functioning, the voltage will follow the motion of the thumbstick as it is moved around. The measurements of the potentiometer resistance change are needed to read the thumbstick's physical position. That's why the MCP3204, a 12-bit A/D converter with conversion rates of up to 100ksps from Microchip, connects the thumbstick with mikroBUS™ using a simple serial interface compatible with the SPI protocol to determine the value of the joystick's X and Y. As the MCP3204 has a resolution of 12 bits, the values on each analog channel (axis) can vary from 0 to 4095. So, if the stick is moved on the X axis from one end to the other, the X values will change from 0 to 4095, and a similar thing happens when moved along the

Y axis. The value of the thumbstick staying in its center position is around 2048. Also, the thumbstick has a pushbutton feature that sends an interrupt signal to the host MCU through the INT line of the mikroBUS™ socket. This Click board™ can operate with both 3.3V and 5V logic voltage levels selected via SMD jumper. This way, it is allowed for both 3.3V and 5V capable MCUs to use the communication lines properly. However, the 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.

THUMBSTICK Click hardware overview image

Features overview

Development board

EasyPIC v8 is a development board specially designed for the needs of rapid development of embedded applications. It supports many high pin count 8-bit PIC microcontrollers from Microchip, regardless of their number of pins, and a broad set of unique functions, such as the first-ever embedded debugger/programmer. The development board is well organized and designed so that the end-user has all the necessary elements, such as switches, buttons, indicators, connectors, and others, in one place. Thanks to innovative manufacturing technology, EasyPIC v8 provides a fluid and immersive working experience, allowing access anywhere and under any

circumstances at any time. Each part of the EasyPIC v8 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 a wide range of external power sources, including a battery, an external 12V power supply, and a power source via the USB Type-C (USB-C) connector.

Communication options such as USB-UART, USB DEVICE, and CAN are also included, including the well-established mikroBUS™ standard, two display options (graphical and character-based LCD), and several different DIP sockets. These sockets cover a wide range of 8-bit PIC MCUs, from the smallest PIC MCU devices with only eight up to forty pins. EasyPIC v8 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 v8 horizontal image

Microcontroller Overview

MCU Card / MCU

PIC18LF46K40

Architecture

PIC

MCU Memory (KB)

64

Silicon Vendor

Microchip

Pin count

40

RAM (Bytes)

3728

Used MCU Pins

mikroBUS™ mapper

NC
NC
AN
NC
NC
RST
SPI Chip Select
RE0
CS
SPI Clock
RC3
SCK
SPI Data OUT
RC4
MISO
SPI Data IN
RC5
MOSI
Power Supply
3.3V
3.3V
Ground
GND
GND
NC
NC
PWM
Interrupt
RB0
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

Click board™ Schematic

THUMBSTICK Click Schematic schematic

Step by step

Project assembly

EasyPIC v8 front image hardware assembly

Start by selecting your development board and Click board™. Begin with the EasyPIC v8 as your development board.

EasyPIC v8 front image hardware assembly
Buck 22 Click front image hardware assembly
MCU DIP 40 hardware assembly
EasyPIC v8 DIP 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
Necto image step 8 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

1. Application Output - In Debug mode, the 'Application Output' window enables real-time data monitoring, offering direct insight into execution results. Ensure proper data display by configuring the environment correctly using the provided tutorial.

2. UART Terminal - Use the UART Terminal to monitor data transmission via a USB to UART converter, allowing direct communication between the Click board™ and your development system. Configure the baud rate and other serial settings according to your project's requirements to ensure proper functionality. For step-by-step setup instructions, refer to the provided tutorial.

3. Plot Output - The Plot feature offers a powerful way to visualize real-time sensor data, enabling trend analysis, debugging, and comparison of multiple data points. To set it up correctly, follow the provided tutorial, which includes a step-by-step example of using the Plot feature to display Click board™ readings. To use the Plot feature in your code, use the function: plot(*insert_graph_name*, variable_name);. This is a general format, and it is up to the user to replace 'insert_graph_name' with the actual graph name and 'variable_name' with the parameter to be displayed.

Software Support

Library Description

This library contains API for Thumbstick Click driver.

Key functions:

  • thumbstick_button_state - Get state of thumbstick button function

  • thumbstick_get_position - Get thumbstick position by axis 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 Thumbstick Click example
 * 
 * # Description
 * The demo application shows clickboard axis postioning and button pressed.
 *
 * The demo application is composed of two sections :
 * 
 * ## Application Init 
 * Initialization of click board's and log's objects.
 * 
 * ## Application Task  
 * It reads the position of the thumbstick,
 *  - You will get data on log on every change of thumbstick axis position, or if you hold 
 *      thumbstick in one postion it will repeat the same log when timer reaches timeout.
 *  - You will get data on log whenever you press thumbstick button and release it.
 * 
 * \author Luka Filipovic
 *
 */
// ------------------------------------------------------------------- INCLUDES

#include "board.h"
#include "log.h"
#include "thumbstick.h"

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

static thumbstick_t thumbstick;
static log_t logger;


static uint8_t old_butt_state;
static uint8_t button_state;

static thumbstick_position_t old_pos;
static thumbstick_position_t thumbstick_pos;

static uint16_t timer_cnt;
#define TIMER_FLAG 1000

static bool change_state;

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

void application_init ( void )
{
    log_cfg_t log_cfg;
    thumbstick_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.

    thumbstick_cfg_setup( &cfg );
    THUMBSTICK_MAP_MIKROBUS( cfg, MIKROBUS_1 );
    thumbstick_init( &thumbstick, &cfg );
    
    thumbstick_set_sensitivity( POSTION_SENS_DEFAULT );
    
    thumbstick_get_position( &thumbstick, &old_pos );
    old_butt_state = thumbstick_button_state( &thumbstick );
    timer_cnt = 0;
    change_state = false;
}

void application_task ( void )
{
    //Button pressed
    button_state = thumbstick_button_state( &thumbstick );

    if ( old_butt_state != button_state )
    {
        if ( button_state == THUMBSTICK_PRESS_BUTTON )
        {
            log_printf( &logger, ">> Button is pressed \r\n" );
            Delay_ms( 100 );
        }
        else
        {
            log_printf( &logger, ">> Button is released \r\n" );
            Delay_ms( 100 );
        }
        old_butt_state = button_state;
    }

    //Thumbstick postion
    thumbstick_get_position( &thumbstick, &thumbstick_pos );
    
    if ( ( old_pos.vertical != thumbstick_pos.vertical ) || ( timer_cnt >= TIMER_FLAG ) )
    {
        if ( thumbstick_pos.vertical == THUMBSTICK_POSITION_TOP )
        {
            log_printf( &logger, ">> TOP \r\n" );
            change_state = true;
        }
        else if ( thumbstick_pos.vertical == THUMBSTICK_POSITION_BOTTOM )
        {
            log_printf( &logger, ">> BOTTOM \r\n" );
            change_state = true;
        }
        
        old_pos = thumbstick_pos;
    }
    
    if ( (old_pos.horizontal != thumbstick_pos.horizontal ) || ( timer_cnt >= TIMER_FLAG )  )
    {
        if ( thumbstick_pos.horizontal == THUMBSTICK_POSITION_LEFT )
        {
            log_printf( &logger, ">> LEFT \r\n" );
            change_state = true;
        }
        else if ( thumbstick_pos.horizontal == THUMBSTICK_POSITION_RIGHT )
        {
            log_printf( &logger, ">> RIGHT \r\n" );
            change_state = true;
        }
        
        old_pos = thumbstick_pos;
    }
    
    if ( ( timer_cnt >= TIMER_FLAG ) || ( change_state == true )  )
    {
        timer_cnt = 0;
        change_state = false;
    }
    
    timer_cnt++;
    Delay_ms( 1 );
}

void main ( void )
{
    application_init( );

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


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

Additional Support

Resources

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