Beginner
10 min

Drive unipolar stepper motors with ULN2003A and STM32F407VGT6

Ideal for projects that require precise control over stepper motors, such as automated machinery, robotics, and precision positioning systems

Stepper 3 Click with Discovery kit with STM32F407VG MCU

Published Mar 15, 2024

Click board™

Stepper 3 Click

Dev. board

Discovery kit with STM32F407VG MCU

Compiler

NECTO Studio

MCU

STM32F407VGT6

High-voltage, high-current Darlington transistor array designed to control the current flow from a supply voltage through the motor coil by activating one of its seven high-power Darlington output stages

A

A

Hardware Overview

How does it work?

Stepper 3 Click is based on the ULN2003A, a high-voltage, high-current Darlington transistor array from Texas Instruments. Motor step progression is performed by alternating the active driver, which sinks the current through the coil connected to the respective driver. The MCU performs the alteration cycle, which controls the driver inputs: a HIGH logic level on the input pin will set the corresponding driver to a LOW logic level, allowing it to sink current. Besides driving a unipolar stepper motor as the primary function, this Click board™ can also be used for driving relays and brushed DC motors

or as the logic buffer for various applications. Combining more than one driver makes it possible to sink more than 500mA. Stepper 3 Click uses four GPIOs to allow the host MCU to control the stepper motor or other mentioned device. Those pins are labeled as INA, INB, INC, and IND. Four output channels from the ULN2203A and a motor power supply are routed to the unpopulated 5-pin header. The motor can be powered over the 5V rail of the mikroBUSTM socket or the external power supply terminal with voltages of 5 – 30V. The selection can be made over the MOTOR PWR jumper. In

addition, the ULN2003As output channels are also routed to the four output LEDs (outA, outB, outC, and outD) for a visual presentation. This Click board™ can be operated only with a 5V logic voltage level. The board must perform appropriate logic voltage level conversion before using MCUs with different logic levels. Also, it comes equipped with a library containing functions and an example code that can be used as a reference for further development.

Stepper 3 Click hardware overview image

Features overview

Development board

Discovery kit with STM32F407VG MCU, powered by the STM32F407 microcontroller, simplifies audio application development. It offers a robust platform with features like the ST-LINK/V2-A debugger, STMEMS digital accelerometer, digital microphone, and integrated audio DAC with a class D speaker driver. It has LEDs, push buttons, and a USB OTG

Micro-AB connector for versatile connectivity. The STM32F407VGT6 MCU boasts a 32-bit Arm Cortex-M4 with FPU, 1MB Flash memory, and 192KB RAM, housed in an LQFP100 package. Equipped with USB OTG FS, MEMS accelerometer, omnidirectional digital microphone, and user-friendly buttons, it ensures seamless operation.

The board accommodates various add-ons via extension headers while offering flexible power supply options, including ST-LINK, USB VBUS, or external sources. Supported by comprehensive free software and a range of IDEs, it empowers developers with flexibility and ease of use, making it an ideal choice for audio-centric projects.

Discovery kit with STM32F407VG MCU double side image

Microcontroller Overview

MCU Card / MCU

default

Architecture

ARM Cortex-M4

MCU Memory (KB)

10

Silicon Vendor

STMicroelectronics

Pin count

100

RAM (Bytes)

100

You complete me!

Accessories

STM32F4 Discovery Shield is the perfect extension for your STM32F4 Discovery Board from STMicroelectronics. This versatile shield features four mikroBUS™ host sockets, a USB-UART module, and a CAN transceiver, expanding the capabilities of your Discovery board. Acting as a docking station, the STM32F4 Discovery Shield enables you to effortlessly transform your board into various applications, whether it's an RFID lock, SMS-triggered control switch, GPS tracking device, full-blown weather station, or any other idea you have in mind. With its seamless integration and enhanced functionality, this shield empowers you to explore endless possibilities and quickly bring your projects to life.

STM32F4 Discovery Shield accessories 1 image

The 28BYJ-48 is an adaptable 5VDC stepper motor with a compact design, ideal for various applications. It features four phases, a speed variation ratio of 1/64, and a stride angle of 5.625°/64 steps, allowing precise control. The motor operates at a frequency of 100Hz and has a DC resistance of 50Ω ±7% at 25°C. It boasts an idle in-traction frequency greater than 600Hz and an idle out-traction frequency exceeding 1000Hz, ensuring reliability in different scenarios. With a self-positioning torque and in-traction torque both exceeding 34.3mN.m at 120Hz, the 28BYJ-48 offers robust performance. Its friction torque ranges from 600 to 1200 gf.cm, while the pull-in torque is 300 gf.cm. This motor makes a reliable and efficient choice for your stepper motor needs.

Stepper 3 Click accessories 1 image

Used MCU Pins

mikroBUS™ mapper

Channel A Control Input
PC1
AN
Channel B Control Input
PE10
RST
Channel C Control Input
PB12
CS
NC
NC
SCK
NC
NC
MISO
NC
NC
MOSI
NC
NC
3.3V
Ground
GND
GND
Channel D Control Input
PA1
PWM
NC
NC
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

Stepper 3 Click Schematic schematic

Step by step

Project assembly

STM32F4 Discovery Shield front image hardware assembly

Start by selecting your development board and Click board™. Begin with the Discovery kit with STM32F407VG MCU as your development board.

STM32F4 Discovery Shield front image hardware assembly
Discovery kit with STM32F407VG MCU front image hardware assembly
BATT Boost Click front image hardware assembly
Prog-cut hardware assembly
BATT Boost Click complete accessories setup image hardware assembly
Board mapper by product8 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 Stepper 3 Click driver.

Key functions:

  • stepper3_set_step_mode - This function sets the step mode resolution settings in ctx->step_mode

  • stepper3_set_direction - This function sets the motor direction to clockwise or counter-clockwise in ctx->direction

  • stepper3_drive_motor - This function drives the motor for the specific number of steps at the selected speed

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 Stepper 3 Click Example.
 *
 * # Description
 * This example demonstrates the use of the Stepper 3 Click board by driving the 
 * motor in both directions for a desired number of steps.
 *
 * The demo application is composed of two sections :
 *
 * ## Application Init
 * Initializes the driver and logger.
 *
 * ## Application Task
 * Drives the motor clockwise for 64 full steps and then counter-clockiwse for 128 half
 * steps with 2 seconds delay before changing the direction. All data is being logged on
 * the USB UART where you can track the program flow.
 *
 * @note
 * Step Motor 5v [MIKROE-1530] is a fully compatible stepper motor for this Click board:
 * https://www.mikroe.com/step-motor-5v
 *
 * @author Stefan Filipovic
 *
 */

#include "board.h"
#include "log.h"
#include "stepper3.h"

static stepper3_t stepper3;   /**< Stepper 3 Click driver object. */
static log_t logger;    /**< Logger object. */

void application_init ( void ) 
{
    log_cfg_t log_cfg;  /**< Logger config object. */
    stepper3_cfg_t stepper3_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.
    stepper3_cfg_setup( &stepper3_cfg );
    STEPPER3_MAP_MIKROBUS( stepper3_cfg, MIKROBUS_1 );
    if ( DIGITAL_OUT_UNSUPPORTED_PIN == stepper3_init( &stepper3, &stepper3_cfg ) ) 
    {
        log_error( &logger, " Communication init." );
        for ( ; ; );
    }
    
    log_info( &logger, " Application Task " );
}

void application_task ( void ) 
{
    log_printf ( &logger, " Move 64 full steps clockwise \r\n\n" );
    stepper3_set_step_mode ( &stepper3, STEPPER3_MODE_FULL_STEP );
    stepper3_set_direction ( &stepper3, STEPPER3_DIR_CW );
    stepper3_drive_motor ( &stepper3, 64, STEPPER3_SPEED_FAST );
    Delay_ms ( 1000 );
    Delay_ms ( 1000 );

    log_printf ( &logger, " Move 128 half steps counter-clockwise \r\n\n" );
    stepper3_set_step_mode ( &stepper3, STEPPER3_MODE_HALF_STEP );
    stepper3_set_direction ( &stepper3, STEPPER3_DIR_CCW );
    stepper3_drive_motor ( &stepper3, 128, STEPPER3_SPEED_VERY_FAST );
    Delay_ms ( 1000 );
    Delay_ms ( 1000 );
}

int main ( void ) 
{
    /* Do not remove this line or clock might not be set correctly. */
    #ifdef PREINIT_SUPPORTED
    preinit();
    #endif
    
    application_init( );
    
    for ( ; ; ) 
    {
        application_task( );
    }

    return 0;
}

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

Additional Support

Resources

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