Beginner
10 min

Ensure silent and smooth motion control for your stepper motor with DRV8426 and ATmega1284

Seamless motion control at your fingertips!

Stepper 18 Click with EasyAVR v7

Published Oct 28, 2023

Click board™

Stepper 18 Click

Dev. board

EasyAVR v7

Compiler

NECTO Studio

MCU

ATmega1284

Experience seamless motion control with our user-friendly integrated motor-driver solution, designed for bipolar stepper motors

A

A

Hardware Overview

How does it work?

Stepper 18 Click is based on the DRV8426, an integrated motor-driver solution for bipolar stepper motors with integrated current sense, 1/256 microstepping, STEP/DIR interface, and smart-tune technology Texas Instruments. It provides the maximum integration by integrating two N-channel power MOSFET H-bridges, current sense resistors and regulation circuitry, and a microstepping indexer capable of driving up to 1.5A full-scale output current. Stepper motor drivers need to re-circulate the winding current by implementing several decay modes, like slow, mixed, and fast decay. The DRV8426 comes with smart-tune decay modes, representing a decay mechanism that automatically adjusts for optimal current regulation performance agnostic of voltage, motor speed, variation, and aging effects. Along with this automatic smart-tune, DRV8426 provides traditional decay modes like slow-mixed and mixed decay. The voltage at the VREF pin adjusts the current regulation set-point obtained by the MCP4726, a 12-bit digital-to-analog converter from Microchip. Thus, the digital value is

converted to the appropriate voltage level (VCC) proportional to the received 12-bit number. The MCP4726 also integrates EEPROM for storing DAC register and configuration bit values and communicates with the MCU through the I2C 2-Wire interface supporting Standard (100 kHz), Fast (400 kHz), and High-Speed (3.4 MHz) I2C modes. In addition to I2C communication, the Stepper 18 Click communicates with MCU using several GPIO pins. A simple STEP/DIR interface, labeled as STP and DIR routed to the PWM and AN pins on the mikroBUS™ socket, allows MCU to manage the direction and step rate of the stepper motor. The internal microstepping indexer can execute high-accuracy microstepping without requiring the MCU to handle the winding current level. The indexer can achieve full step, half step, 1/4, 1/8, 1/16, 1/32, 1/64, 1/128, and 1/256 microstepping through the M0 and M1 pins routed to the onboard SMD switch. Also, high microstepping contributes to significant audible noise reduction and smooth motion. The Enable pin, labeled as EN and routed to the CS pin of the mikroBUS™ socket, optimizes

power consumption and is used for power ON/OFF purposes. All circuits, including the interface pins, are inactive in this state, and the DRV8426 is in the form of minimum power consumption. Also, a low-power Sleep feature is included, routed to the RST pin of the mikroBUS™ socket alongside the fault-interrupt feature routed to the INT pin of the mikroBUS™ socket. The Sleep Mode allows the system to save power when not actively driving the motor. This Click board™ supports an external power supply for the motor, which can be connected to the input terminal labeled as VM and should be within the range of 4.5V to 33V, while the stepper motor coils can be connected to the terminals labeled as A1, B2, B1, and A2. This Click board™ can be operated only with a 3.3V 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 18 Click hardware overview image

Features overview

Development board

EasyAVR v7 is the seventh generation of AVR development boards specially designed for the needs of rapid development of embedded applications. It supports a wide range of 16-bit AVR microcontrollers from Microchip and has a broad set of unique functions, such as a powerful onboard mikroProg programmer and In-Circuit debugger over USB. 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, EasyAVR v7 allows you to connect accessory boards, sensors, and custom electronics more

efficiently than ever. Each part of the EasyAVR 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 a wide range of external power sources, including an external 12V power supply, 7-12V AC or 9-15V 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 which cover a wide range of 16-bit AVR MCUs. EasyAVR 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.

EasyAVR v7 horizontal image

Microcontroller Overview

MCU Card / MCU

ATmega1284

Architecture

AVR

MCU Memory (KB)

128

Silicon Vendor

Microchip

Pin count

40

RAM (Bytes)

16384

You complete me!

Accessories

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 18 Click accessories image

Used MCU Pins

mikroBUS™ mapper

Stepping Direction
PA7
AN
Sleep Mode
PA6
RST
Enable
PA5
CS
NC
NC
SCK
NC
NC
MISO
NC
NC
MOSI
Power Supply
3.3V
3.3V
Ground
GND
GND
Step Rate
PD4
PWM
Fault Indicator
PD2
INT
NC
NC
TX
NC
NC
RX
I2C Clock
PC0
SCL
I2C Data
PC1
SDA
NC
NC
5V
Ground
GND
GND
1

Take a closer look

Click board™ Schematic

Stepper 18 Click Schematic schematic

Step by step

Project assembly

EasyAVR v7 front image hardware assembly

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

EasyAVR v7 front image hardware assembly
GNSS2 Click front image hardware assembly
MCU DIP 40 hardware assembly
GNSS2 Click complete accessories setup image hardware assembly
EasyAVR v7 Access 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
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

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 18 Click driver.

Key functions:

  • stepper18_set_out_voltage - Set voltage reference.

  • stepper18_set_dir - Set direction.

  • stepper18_move_motor_angle - Move motor in angle value.

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 Stepper18 Click example
 *
 * # Description
 * This example showcases the device's ability to control the motor.
 * It initializes the device for control and moves the motor in two 
 * directions in a variety of speeds for 360 degrees.
 *
 * The demo application is composed of two sections :
 *
 * ## Application Init
 * Initializes UART and I2C communication modules, and additional  
 * pins for motor control, and set's default configuration
 *
 * ## Application Task
 * First it move motor clockwise for 360 degrees in medium speed. 
 * Then changes direction and moves motor for 180 degrees in slow speed,
 * and additional 180 degrees in fast speed.
 *
 * @note
 * Step resolution is changed by the switches[ M0, M1 ] on device.
 * Full step    :   M0=>0 ,     M1=>0
 * Half step    :   M0=>1 ,     M1=>0
 * Quarter step :   M0=>0 ,     M1=>1
 * 1/8 step     :   M0=>1 ,     M1=>1
 * 1/16 step    :   M0=>Hi-Z ,  M1=>1
 * 1/32 step    :   M0=>0 ,     M1=>Hi-Z
 * 1/64 step    :   M0=>Hi-Z ,  M1=>0
 * 1/128 step   :   M0=>Hi-Z ,  M1=>Hi-Z
 * 1/256 step   :   M0=>1 ,     M1=>0
 *
 * @author Luka Filipovic
 *
 */

#include "board.h"
#include "log.h"
#include "stepper18.h"

static stepper18_t stepper18;
static log_t logger;

void application_init ( void ) 
{
    log_cfg_t log_cfg;  /**< Logger config object. */
    stepper18_cfg_t stepper18_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.
    stepper18_cfg_setup( &stepper18_cfg );
    STEPPER18_MAP_MIKROBUS( stepper18_cfg, MIKROBUS_1 );
    err_t init_flag = stepper18_init( &stepper18, &stepper18_cfg );
    if ( init_flag == I2C_MASTER_ERROR ) 
    {
        log_error( &logger, " Application Init Error. " );
        log_info( &logger, " Please, run program again... " );
        for ( ; ; );
    }

    stepper18_default_cfg ( &stepper18 );
    log_info( &logger, " Application Task " );
    stepper18_set_dir( &stepper18, 0 );
}

void application_task ( void ) 
{
    static uint8_t direction = 0;
    log_printf( &logger, "> Move 360deg in CW direction.\r\n" );
    stepper18_move_motor_angle( &stepper18, 360, STEPPER18_STEP_RES_FULL, STEPPER18_SPEED_MEDIUM );
    direction = !direction;
    stepper18_set_dir( &stepper18, direction );
    Delay_ms ( 500 );
    log_printf( &logger, "> Move 180deg in CCW direction.\r\n" );
    stepper18_move_motor_angle( &stepper18, 180, STEPPER18_STEP_RES_FULL, STEPPER18_SPEED_SLOW );
    Delay_ms ( 1000 );
    log_printf( &logger, "> Move 180deg in CCW direcion.\r\n" );
    stepper18_move_motor_angle( &stepper18, 180, STEPPER18_STEP_RES_FULL, STEPPER18_SPEED_FAST );
    direction = !direction;
    stepper18_set_dir( &stepper18, direction );
    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
/*!
 * @file main.c
 * @brief Stepper18 Click example
 *
 * # Description
 * This example showcases the device's ability to control the motor.
 * It initializes the device for control and moves the motor in two 
 * directions in a variety of speeds for 360 degrees.
 *
 * The demo application is composed of two sections :
 *
 * ## Application Init
 * Initializes UART and I2C communication modules, and additional  
 * pins for motor control, and set's default configuration
 *
 * ## Application Task
 * First it move motor clockwise for 360 degrees in medium speed. 
 * Then changes direction and moves motor for 180 degrees in slow speed,
 * and additional 180 degrees in fast speed.
 *
 * @note
 * Step resolution is changed by the switches[ M0, M1 ] on device.
 * Full step    :   M0=>0 ,     M1=>0
 * Half step    :   M0=>1 ,     M1=>0
 * Quarter step :   M0=>0 ,     M1=>1
 * 1/8 step     :   M0=>1 ,     M1=>1
 * 1/16 step    :   M0=>Hi-Z ,  M1=>1
 * 1/32 step    :   M0=>0 ,     M1=>Hi-Z
 * 1/64 step    :   M0=>Hi-Z ,  M1=>0
 * 1/128 step   :   M0=>Hi-Z ,  M1=>Hi-Z
 * 1/256 step   :   M0=>1 ,     M1=>0
 *
 * @author Luka Filipovic
 *
 */

#include "board.h"
#include "log.h"
#include "stepper18.h"

static stepper18_t stepper18;
static log_t logger;

void application_init ( void ) 
{
    log_cfg_t log_cfg;  /**< Logger config object. */
    stepper18_cfg_t stepper18_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.
    stepper18_cfg_setup( &stepper18_cfg );
    STEPPER18_MAP_MIKROBUS( stepper18_cfg, MIKROBUS_1 );
    err_t init_flag = stepper18_init( &stepper18, &stepper18_cfg );
    if ( init_flag == I2C_MASTER_ERROR ) 
    {
        log_error( &logger, " Application Init Error. " );
        log_info( &logger, " Please, run program again... " );
        for ( ; ; );
    }

    stepper18_default_cfg ( &stepper18 );
    log_info( &logger, " Application Task " );
    stepper18_set_dir( &stepper18, 0 );
}

void application_task ( void ) 
{
    static uint8_t direction = 0;
    log_printf( &logger, "> Move 360deg in CW direction.\r\n" );
    stepper18_move_motor_angle( &stepper18, 360, STEPPER18_STEP_RES_FULL, STEPPER18_SPEED_MEDIUM );
    direction = !direction;
    stepper18_set_dir( &stepper18, direction );
    Delay_ms ( 500 );
    log_printf( &logger, "> Move 180deg in CCW direction.\r\n" );
    stepper18_move_motor_angle( &stepper18, 180, STEPPER18_STEP_RES_FULL, STEPPER18_SPEED_SLOW );
    Delay_ms ( 1000 );
    log_printf( &logger, "> Move 180deg in CCW direcion.\r\n" );
    stepper18_move_motor_angle( &stepper18, 180, STEPPER18_STEP_RES_FULL, STEPPER18_SPEED_FAST );
    direction = !direction;
    stepper18_set_dir( &stepper18, direction );
    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

Love this project?

'Buy This Kit' button takes you directly to the shopping cart where you can easily add or remove products.