Intermediate
30 min

Keep your devices running smoothly with TPS3430 and STM32F031K6

Silent protector, robust performer: Meet the watchdog timer

Watchdog Click with Nucleo 32 with STM32F031K6 MCU

Published Oct 01, 2024

Click board™

Watchdog Click

Dev. board

Nucleo 32 with STM32F031K6 MCU

Compiler

NECTO Studio

MCU

STM32F031K6

Your system's best friend, the Watchdog Timer, tirelessly monitors and resets your device when it detects abnormal behavior, guaranteeing consistent performance.

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Hardware Overview

How does it work?

Watchdog Click is based on the TPS3430, a standalone watchdog timer with a programmable watchdog window and reset delay from Texas Instruments. This high-accuracy programmable timer with the disable feature achieves 15% watchdog timing accuracy over the extended temperature range. A window watchdog is typically employed in safety-critical applications where a traditional watchdog timer is inadequate. With a traditional timer, there is a maximum time in which a pulse must be issued to prevent the reset from occurring. However, in a window watchdog, the pulse must be issued between a maximum lower window time and the minimum upper window time set by the programmable timeout pin and two logic input pins. This Click board™ communicates with MCU using several GPIO pins and offers programmable watchdog timeout and reset delay. The two pins that this

Click board™ uses represent a watchdog input and output, with two additional logic inputs with whom the user can select the watchdog window ratios timeouts and turn off the watchdog timer. The watchdog input pin labeled as WDI routed on the PWM pin of the mikroBUS™ socket is ignored for the watchdog reset delay upon Startup. After Startup, the watchdog input signal must arrive within the watchdog window to prevent a watchdog reset whose delay duration may be configured with the CRST SEL on-board jumper. The user has two options: leaving the CRST pin pulled high with a pull-up resistor or connecting the CRST to a capacitor connected to GND. Similarly to the watchdog reset delay, the user can configure the watchdog timeout using the S0 and S1 pins, routed on the RST and CS pins of the mikroBUS™ socket and CWD SEL on-board jumper. This jumper can connect the CRST pin

with a pull-up resistor or a capacitor connected to GND. When a watchdog fault occurs due to an incorrectly timed watchdog input signal, the WDO pin activates and performs the transition to logic low state for the watchdog reset delay, indicated with a red LED labeled WDT FLT. When the delay expires, the WDO pin deactivates and returns to a logic high state. When the watchdog is disabled using S0 and S1 pins, the watchdog input is ignored, and the WDO pin is in a Hi-Z and remains logic-high due to the R5 external pull-up resistor. 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.

Watchdog 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
Watchdog Control 0
PA11
RST
Watchdog Control 1
PA4
CS
NC
NC
SCK
NC
NC
MISO
NC
NC
MOSI
Power Supply
3.3V
3.3V
Ground
GND
GND
Watchdog Input
PA8
PWM
Watchdog Output
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

Watchdog 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
Stepper 22 Click front image hardware assembly
Prog-cut hardware assembly
Nucleo-32 with STM32 MCU Access 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
STM32 M4 Clicker HA MCU/Select 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 Watchdog Click driver.

Key functions:

  • watchdog_set_set0 - Set S0 ( RST ) pin state function.

  • watchdog_get_wdo - Get WDO ( INT ) pin state function.

  • watchdog_send_pulse - Send pulse 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 main.c
 * @brief Watchdog Click Example.
 *
 * # Description
 * This is an example that demonstrates the use of the Watchdog click board.
 *
 * The demo application is composed of two sections :
 *
 * ## Application Init
 * Initialization driver enables - GPIO, configure the watchdog window,
 * enable watchdog, also write log.
 *
 * ## Application Task
 * In the first part of the example,
 * we send pulses in a valid time window (Correct Operation).
 * The second part of the example sends pulses outside the valid time window
 * and then the watchdog detects a fault condition, display "Fault",
 * performs the reset and turn on the LED ( WDT FLT ) on the Watchdog click board.
 * Results are being sent to the Usart Terminal where you can track their changes.
 *
 *
 * @author Stefan Ilic
 *
 */

#include "board.h"
#include "log.h"
#include "watchdog.h"

static watchdog_t watchdog;   /**< Watchdog Click driver object. */
static log_t logger;    /**< Logger object. */

void application_init ( void ) 
{
    log_cfg_t log_cfg;  /**< Logger config object. */
    watchdog_cfg_t watchdog_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.
    watchdog_cfg_setup( &watchdog_cfg );
    WATCHDOG_MAP_MIKROBUS( watchdog_cfg, MIKROBUS_1 );
    if ( DIGITAL_OUT_UNSUPPORTED_PIN == watchdog_init( &watchdog, &watchdog_cfg ) ) {
        log_error( &logger, " Application Init Error. " );
        log_info( &logger, " Please, run program again... " );

        for ( ; ; );
    }
    watchdog_default_cfg ( &watchdog );
    
    log_printf( &logger, "---------------------\r\n" );
    log_printf( &logger, "   Configure of the  \r\n" );
    log_printf( &logger, "   watchdog window   \r\n" );
    watchdog_setup_time( &watchdog, WATCHDOG_SETUP_TIME_MODE_2 );
    Delay_ms( 1000 );
    
    log_printf( &logger, "---------------------\r\n" );
    log_printf( &logger, "   Watchdog enabled  \r\n" );
    log_printf( &logger, "---------------------\r\n" );
    Delay_ms( 1000 );
    
    log_info( &logger, " Application Task " );
}

void application_task ( void ) 
{
    log_printf( &logger, "  Correct Operation  \r\n" );
    uint8_t n_cnt = 40;
    while ( n_cnt > 0 ) {
        watchdog_send_pulse( &watchdog, 1 );
        Delay_ms( 50 );
        n_cnt--;
    }
    log_printf( &logger, "---------------------\r\n" );

    log_printf( &logger, "        Fault        \r\n" );
    n_cnt = 8;
    while ( n_cnt > 0 ) {
        watchdog_send_pulse( &watchdog, 1 );
        Delay_ms( 250 );
        n_cnt--;
    }
    log_printf( &logger, "---------------------\r\n" );
}

void main ( void ) 
{
    application_init( );

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

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

Additional Support

Resources

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