Intermediate
30 min

Achieve versatility in motor control with STSPIN250 and ATmega1284

Unleash the power of brushed DC motor control!

STSPIN250 Click with EasyAVR v8

Published Jul 09, 2024

Click board™

STSPIN250 Click

Dev. board

EasyAVR v8

Compiler

NECTO Studio

MCU

ATmega1284

Experience enhanced motor performance with our brushed DC motor driver, optimizing efficiency, reducing wear, and extending the operational lifespan of your motors

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Hardware Overview

How does it work?

STSPIN250 Click is based on the STSPIN250, a low voltage DC brushed motor driver by STMicroelectronics. This device integrates two full-bridge MOSFET channels in a parallel configuration, sustaining up to 2.6A. This IC targets battery-powered applications, featuring optimizations toward lowered power consumption. It has a PWM current controller with a fixed OFF time, during which the current decay sequence is performed. This effectively limits the current through the connected load (motor). The OFF (decay) time is approximately 40 µs on this Click board™. The PWM current controller compares the voltage across the sense resistor (VSENS) and the VREF voltage, which is adjustable on STSPIN250 click. When VSENS exceeds the VREF voltage, the current limiting is triggered, and the OFF timer starts counting. The decay sequence is performed. Knowing the RSENS, it can be easily calculated how much voltage should be applied to the REF pin of the STSPIN250 to limit the current according to ILOAD. For example, if 0.388V is applied at the VREF pin, the current limit will be maxed out to 2.58A. The onboard

potentiometer allows you to adjust the VREF voltage according to needs simply. The connected motor can be controlled by using these pins: PWM, PH, RST, and EN/INT. The PH pin determines the direction of the current. If set to a HIGH logic level, the current will flow in one direction, and vice-versa: when a LOW logic level is applied, the current will reverse its direction. This pin is routed to the AN pin of the mikroBUS™ and labeled as PH. PWM pin can be used to regulate the speed of the rotation. When this pin has a LOW logic level, the current will start circulating through the low-side (LS) MOSFETs and the motor coil. When there is a HIGH logic level on this pin, the current will flow through the load, depending on the logic state of the PH pin. A higher duty cycle percentage will result in higher angular speed. While the current decay sequence is performed, the logic states on the input pins will be disregarded until the decay timer expires. The decay time is fixed to approximately 40 µs on this Click board™. The STBY/RESET (RST) pin of the STSPIN250 is used to set both bridge outputs in HIGH-Z mode, disconnecting the power supply

from the output stage. This pin allows lower average power consumption as no current can flow from the power supply to the motor. This pin is routed to the RST pin of the mikroBUS™. The EN/FAULT (EN) pin has a double purpose: when set to a high logic level, it acts as a chip enable, allowing the device to operate. In the case of a fault condition on the IC, it will be asserted to a LOW logic level, acting as an interrupt pin. A restart attempt will be made after a timeout period defined by the external capacitor and resistor values. This pin is routed to the CS and INT pin of the mikroBUS™, allowing the host MCU to use both functions. These pins are labeled EN and FLT on the Click board™, respectively. The motor power supply can be connected to the input terminal labeled as VIN and should be within the range of 1.8V to 10V. The motor can be connected at the second terminal, between two poles labeled as A+ and A-. The Click board™ requires an external power supply for the motor to work. However, it also requires 3.3V from the mikroBUS™ rail.

STSPIN250 Click hardware overview image

Features overview

Development board

EasyAVR v8 is a development board designed to rapidly develop embedded applications based on 8-bit AVR microcontrollers (MCUs). Redesigned from the ground up, EasyAVR v8 offers a familiar set of standard features, as well as some new and unique features standard for the 8th generation of development boards: programming and debugging over the WiFi network, connectivity provided by USB-C connectors, support for a wide range of different MCUs, and more. The development board is designed so that the developer has everything that might be needed for the application development, following the Swiss Army knife concept: a highly advanced programmer/debugger module, a reliable power supply module, and a USB-UART connectivity option. EasyAVR v8 board offers several different DIP sockets, covering a wide range of 8-bit AVR MCUs, from the smallest

AVR MCU devices with only eight pins, all the way up to 40-pin "giants". The development board supports the well-established mikroBUS™ connectivity standard, offering five mikroBUS™ sockets, allowing access to a huge base of Click boards™. EasyAVR v8 offers two display options, allowing even the basic 8-bit AVR MCU devices to utilize them and display graphical or textual content. One of them is the 1x20 graphical display connector, compatible with the familiar Graphical Liquid Crystal Display (GLCD) based on the KS108 (or compatible) display driver, and EasyTFT board that contains TFT Color Display MI0283QT-9A, which is driven by ILI9341 display controller, capable of showing advanced graphical content. The other option is the 2x16 character LCD module, a four-bit display module with an embedded character-based display controller. It

requires minimal processing power from the host MCU for its operation. There is a wide range of useful interactive options at the disposal: high-quality buttons with selectable press levels, LEDs, pull-up/pulldown DIP switches, and more. All these features are packed on a single development board, which uses innovative manufacturing technologies, delivering a fluid and immersive working experience. The EasyAVR v8 development board is also integral to the MIKROE rapid development ecosystem. Natively supported by the MIKROE Software toolchain, backed up by hundreds of different Click board™ designs with their number growing daily, it covers many different prototyping and development aspects, thus saving precious development time.

EasyAVR v8 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

DC Gear Motor - 430RPM (3-6V) represents an all-in-one combination of a motor and gearbox, where the addition of gear leads to a reduction of motor speed while increasing the torque output. This gear motor has a spur gearbox, making it a highly reliable solution for applications with lower torque and speed requirements. The most critical parameters for gear motors are speed, torque, and efficiency, which are, in this case, 520RPM with no load and 430RPM at maximum efficiency, alongside a current of 60mA and a torque of 50g.cm. Rated for a 3-6V operational voltage range and clockwise/counterclockwise rotation direction, this motor represents an excellent solution for many functions initially performed by brushed DC motors in robotics, medical equipment, electric door locks, and much more.

STSPIN250 Click accessories 1 image

Used MCU Pins

mikroBUS™ mapper

Direction Control
PA7
AN
Chip Standby/Reset
PA4
RST
Chip Enable
PB4
CS
NC
NC
SCK
NC
NC
MISO
NC
NC
MOSI
Power Supply
3.3V
3.3V
Ground
GND
GND
PWM Speed Control
PD4
PWM
Flaut Reporting
PD2
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

STSPIN250 Click Schematic schematic

Step by step

Project assembly

EasyAVR v8 front image hardware assembly

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

EasyAVR v8 front image hardware assembly
Stepper 24 Click front image hardware assembly
Stepper 24 Click complete accessories setup image hardware assembly
EasyAVR v8 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 STSPIN250 Click driver.

Key functions:

  • stspin250_set_ph - This function regulates Direction control pin state. It controls direction of the current

  • stspin250_enable - This function regulates enable pin state

  • stspin250_reset - This function regulates reset pin state

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 Stspin250 Click example
 * 
 * # Description
 * This application enables usage of brushed DC motor driver with
 * the current limiting and current sensing.
 *
 * The demo application is composed of two sections :
 * 
 * ## Application Init 
 * Initialization driver init, PWM init and enable device
 * 
 * ## Application Task  
 * This is a example which demonstrates the use of Stspin250 Click board.
 * Stspin250 Click communicates with register via PWM interface.
 * It shows moving in the left direction from slow to fast speed
 * and from fast to slow speed.
 * Results are being sent to the Usart Terminal where you can track their changes.
 * 
 * @author Nikola Peric
 *
 */
// ------------------------------------------------------------------- INCLUDES

#include "board.h"
#include "log.h"
#include "stspin250.h"

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

static stspin250_t stspin250;
static log_t logger;
uint8_t motor_direction = 1;

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

void application_init ( void )
{
    log_cfg_t log_cfg;
    stspin250_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.

    stspin250_cfg_setup( &cfg );
    STSPIN250_MAP_MIKROBUS( cfg, MIKROBUS_1 );
    stspin250_init( &stspin250, &cfg );

    stspin250_enable( &stspin250, STSPIN250_DEVICE_ENABLE );
    stspin250_set_duty_cycle ( &stspin250, 0.0 );

    stspin250_pwm_start( &stspin250 );
    log_info( &logger, "---- Application Task ----" );
    Delay_ms ( 500 );
}

void application_task ( void )
{
    static int8_t duty_cnt = 1;
    static int8_t duty_inc = 1;
    float duty = duty_cnt / 10.0;

    if ( motor_direction == 1 )
    {
        stspin250_set_ph( &stspin250, 1 );
        log_printf( &logger, "> CLOCKWISE <\r\n" );
    }
    else
    {
        stspin250_set_ph( &stspin250, 0 );
        log_printf( &logger, "> COUNTER CLOCKWISE <\r\n" );
    }

    stspin250_set_duty_cycle ( &stspin250, duty );
    log_printf( &logger, "Duty: %d%%\r\n", ( uint16_t )( duty_cnt * 10 ) );
    Delay_ms ( 500 );

    if ( 10 == duty_cnt ) 
    {
        duty_inc = -1;
    }
    else if ( 0 == duty_cnt ) 
    {
        duty_inc = 1;
        if ( motor_direction == 1 )
        {
            motor_direction = 0;
        }
        else if ( motor_direction == 0 )
        {
            motor_direction = 1;
        }
    }
    duty_cnt += duty_inc;
}

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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