Beginner
10 min

Achieve precise and natural control using COM-09032 and STM32F031K6

Level up your HMI experience

THUMBSTICK Click with Nucleo 32 with STM32F031K6 MCU

Published Oct 01, 2024

Click board™

THUMBSTICK Click

Dev. board

Nucleo 32 with STM32F031K6 MCU

Compiler

NECTO Studio

MCU

STM32F031K6

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

Nucleo 32 with STM32F031K6 MCU board provides an affordable and flexible platform for experimenting with STM32 microcontrollers in 32-pin packages. Featuring Arduino™ Nano connectivity, it allows easy expansion with specialized shields, while being mbed-enabled for seamless integration with online resources. The

board includes an on-board ST-LINK/V2-1 debugger/programmer, supporting USB reenumeration with three interfaces: Virtual Com port, mass storage, and debug port. It offers a flexible power supply through either USB VBUS or an external source. Additionally, it includes three LEDs (LD1 for USB communication, LD2 for power,

and LD3 as a user LED) and a reset push button. The STM32 Nucleo-32 board is supported by various Integrated Development Environments (IDEs) such as IAR™, Keil®, and GCC-based IDEs like AC6 SW4STM32, making it a versatile tool for developers.

Nucleo 32 with STM32F031K6 MCU double side image

Microcontroller Overview

MCU Card / MCU

default

Architecture

ARM Cortex-M0

MCU Memory (KB)

32

Silicon Vendor

STMicroelectronics

Pin count

32

RAM (Bytes)

4096

You complete me!

Accessories

Click Shield for Nucleo-32 is the perfect way to expand your development board's functionalities with STM32 Nucleo-32 pinout. The Click Shield for Nucleo-32 provides two mikroBUS™ sockets to add any functionality from our ever-growing range of Click boards™. We are fully stocked with everything, from sensors and WiFi transceivers to motor control and audio amplifiers. The Click Shield for Nucleo-32 is compatible with the STM32 Nucleo-32 board, providing an affordable and flexible way for users to try out new ideas and quickly create prototypes with any STM32 microcontrollers, choosing from the various combinations of performance, power consumption, and features. The STM32 Nucleo-32 boards do not require any separate probe as they integrate the ST-LINK/V2-1 debugger/programmer and come with the STM32 comprehensive software HAL library and various packaged software examples. This development platform provides users with an effortless and common way to combine the STM32 Nucleo-32 footprint compatible board with their favorite Click boards™ in their upcoming projects.

Click Shield for Nucleo-32 accessories 1 image

Used MCU Pins

mikroBUS™ mapper

NC
NC
AN
NC
NC
RST
SPI Chip Select
PA4
CS
SPI Clock
PB3
SCK
SPI Data OUT
PB4
MISO
SPI Data IN
PB5
MOSI
Power Supply
3.3V
3.3V
Ground
GND
GND
NC
NC
PWM
Interrupt
PA12
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

Click Shield for Nucleo-144 front image hardware assembly

Start by selecting your development board and Click board™. Begin with the Nucleo 32 with STM32F031K6 MCU as your development board.

Click Shield for Nucleo-144 front image hardware assembly
Nucleo 144 with STM32L4A6ZG MCU front image hardware assembly
2x4 RGB Click front image hardware assembly
Prog-cut hardware assembly
Nucleo-32 with STM32 MCU 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 image step 5 hardware assembly
Necto image step 6 hardware assembly
Clicker 4 for STM32F4 HA 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

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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