Intermediate
30 min

Experience a new era of brushless motor control with L6235 and PIC18LF4680

Achieve optimal performance effortlessly

Brushless 12 Click with EasyPIC v7

Published Nov 01, 2023

Click board™

Brushless 12 Click

Development board

EasyPIC v7

Compiler

NECTO Studio

MCU

PIC18LF4680

Don't let your motors be limited. Take action and integrate advanced brushless motor control for limitless possibilities

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Hardware Overview

How does it work?

Brushless 12 Click is based on the L6235, a fully integrated motor driver specifically developed to drive a wide range of BLDC motors with Hall effect sensors from STMicroelectronics. The L6235 includes a 3-phase DMOS bridge, an OFF-TIME PWM current controller, the decoding logic for single-ended Hall sensors that generate the required power stage sequence, and other features for safe operation and flexibility. It also has a built-in Over Current Detection (OCD) that allows protection against short circuits between the outputs and between output and ground. Integrated decoding logic of the L6235 provides the correct sequence on the three outputs labeled as U V W for motors with 60° and 120° spaced Hall effect sensor signals. The sensor outputs are connected to the device's H1, H2, and H3 inputs through the HALL header. H1 input of the L6235 is internally connected to a monostable that provides a width pulse on the TACHO output. With a pull-up resistor on this output, the resulting

waveform at the pin will be a square wave whose frequency is proportional to the motor rotation speed, with an on-time set by the potentiometer VR1 labeled as TACHO. An additional potentiometer on this Click board™ VR2, labeled OFF-TIME, can be used for a PWM current regulation capacity. VR1 potentiometer defines the on-time integration and is compared to a voltage proportional to the desired speed by the Op-Amp LM358 from STMicroelectronics. The output of the Op-Amp represents the speed error signal. Providing this signal to the VREF input of the L6235, which sets the current in the motor windings, the speed error will act on the motor modifying its torque to maintain the speed at a constant value. This feature of the L6235 can be selected by the switch labeled as VREF, which allows the selection between Torque or Speed Mode. Brushless 12 Click communicates with MCU using several GPIO pins. The RST pin of the mikroBUS™ socket labeled EN represents the

Enable function and serves as Chip Enable that turns OFF all power MOSFETs of the L6235. CS pin labeled BRK switches ON all high-side power MOSFETs and allows the user to use the brake function. And the last GPIO pin routed to the PWM pin of the mikroBUS™ socket labeled as F/R selects the direction of the motor rotation. It also possesses two connectors, where one of them represents an external power supply labeled as VIN in the range from 8 to 48V maximum, and the next one labeled with U V W is a terminal on which the BLDC motor needs to be connected. 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. It comes equipped with a library containing functions and an example code that can be used, as a reference, for further development.

Brushless 12 Click hardware overview image

Features overview

Development board

EasyPIC v7 is the seventh generation of PIC development boards specially designed to develop embedded applications rapidly. It supports a wide range of 8-bit PIC microcontrollers from Microchip and has a broad set of unique functions, such as a powerful onboard mikroProg programmer and In-Circuit debugger over USB-B. 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, EasyPIC v7 allows you to connect accessory boards, sensors, and custom electronics more efficiently than ever. Each part of

the EasyPIC 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 various external power sources, including an external 12V power supply, 7-23V AC or 9-32V 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. These sockets cover a wide range of 8-bit PIC MCUs, from PIC10F, PIC12F, PIC16F, PIC16Enh, PIC18F, PIC18FJ, and PIC18FK families. EasyPIC 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.

EasyPIC v7 horizontal image

Microcontroller Overview

MCU Card / MCU

default

Architecture

PIC

MCU Memory (KB)

64

Silicon Vendor

Microchip

Pin count

40

RAM (Bytes)

3328

You complete me!

Accessories

Brushless DC (BLDC) Motor with a Hall sensor represents a high-performance motor from the 42BLF motor series. This motor, wired in a star configuration, boasts a Hall Effect angle of 120°, ensuring precise and reliable performance. With a compact motor length of 47mm and a lightweight design tipping the scales at just 0.29kg, this BLDC motor is engineered to meet your needs. Operating flawlessly at a voltage rating of 24VDC and a speed range of 4000 ± 10% RPM, this motor offers consistent and dependable power. It excels in a normal operational temperature range from -20 to +50°C, maintaining efficiency with a rated current of 1.9A. Also, this product seamlessly integrates with all Brushless Click boards™ and those that require BLDC motors with Hall sensors.

Brushless 12 Click accessories image

Used MCU Pins

mikroBUS™ mapper

NC
NC
AN
Enable
RE1
RST
Brake
RE0
CS
NC
NC
SCK
NC
NC
MISO
NC
NC
MOSI
NC
NC
3.3V
Ground
GND
GND
Forward/Reverse
RC0
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

Schematic

Brushless 12 Click Schematic schematic

Step by step

Project assembly

EasyPIC v7 front image hardware assembly

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

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

After pressing the "FLASH" button on the left-side panel, it is necessary to open the UART terminal to display the achieved results. By clicking on the Tools icon in the right-hand panel, multiple different functions are displayed, among which is the UART Terminal. Click on the offered "UART Terminal" icon.

UART Application Output Step 1

Once the UART terminal is opened, the window takes on a new form. At the top of the tab are two buttons, one for adjusting the parameters of the UART terminal and the other for connecting the UART terminal. The tab's lower part is reserved for displaying the achieved results. Before connecting, the terminal has a Disconnected status, indicating that the terminal is not yet active. Before connecting, it is necessary to check the set parameters of the UART terminal. Click on the "OPTIONS" button.

UART Application Output Step 2

In the newly opened UART Terminal Options field, we check if the terminal settings are correct, such as the set port and the Baud rate of UART communication. If the data is not displayed properly, it is possible that the Baud rate value is not set correctly and needs to be adjusted to 115200. If all the parameters are set correctly, click on "CONFIGURE".

UART Application Output Step 3

The next step is to click on the "CONNECT" button, after which the terminal status changes from Disconnected to Connected in green, and the data is displayed in the Received data field.

UART Application Output Step 4

Software Support

Library Description

This library contains API for Brushless 12 Click driver.

Key functions:

  • brushless12_set_brake - This function sets the BRK pin to the desired state

  • brushless12_set_direction - This function sets the F/R pin to the desired state

  • brushless12_set_enable - This function sets the EN pin to the desired state

Open Source

Code example

This example can be found in NECTO Studio. Feel free to download the code, or you can copy the code below.

/*!
 * @file main.c
 * @brief Brushless 12 Click Example.
 *
 * # Description
 * This example demonstrates the use of Brushless 12 click board.
 *
 * The demo application is composed of two sections :
 *
 * ## Application Init
 * Initializes the driver and sets the click default configuration.
 *
 * ## Application Task
 * Drives the motor in the forward direction for 5 seconds, then pulls brake for 2 seconds, 
 * and after that drives it in the reverse direction for 5 seconds, and pulls brake for 2 seconds.
 * Each step will be logged on the USB UART where you can track the program flow.
 *
 * @author Stefan Filipovic
 *
 */

#include "board.h"
#include "log.h"
#include "brushless12.h"

static brushless12_t brushless12;       /**< Brushless 12 Click driver object. */
static log_t logger;                    /**< Logger object. */

void application_init ( void ) 
{
    log_cfg_t log_cfg;                  /**< Logger config object. */
    brushless12_cfg_t brushless12_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.

    brushless12_cfg_setup( &brushless12_cfg );
    BRUSHLESS12_MAP_MIKROBUS( brushless12_cfg, MIKROBUS_1 );
    
    if ( brushless12_init( &brushless12, &brushless12_cfg ) == DIGITAL_OUT_UNSUPPORTED_PIN ) 
    {
        log_error( &logger, " Application Init Error. " );
        log_info( &logger, " Please, run program again... " );

        for ( ; ; );
    }
    
    brushless12_default_cfg( &brushless12 );
    Delay_ms( 100 );
    log_info( &logger, " Application Task " );
}

void application_task ( void ) 
{
    log_printf( &logger, "The motor turns forward! \r\n" );
    brushless12_set_direction ( &brushless12, BRUSHLESS12_DIR_FORWARD );
    brushless12_set_brake ( &brushless12, BRUSHLESS12_START );
    Delay_ms( 5000 );
    
    log_printf( &logger, "Pull brake! \r\n" );
    brushless12_set_brake ( &brushless12, BRUSHLESS12_BRAKE );
    Delay_ms( 2000 );
    
    log_printf( &logger, "The motor turns in reverse! \r\n" );
    brushless12_set_direction ( &brushless12, BRUSHLESS12_DIR_REVERSE );
    brushless12_set_brake ( &brushless12, BRUSHLESS12_START );
    Delay_ms( 5000 );
    
    log_printf( &logger, "Pull brake! \r\n" );
    brushless12_set_brake ( &brushless12, BRUSHLESS12_BRAKE );
    Delay_ms( 2000 );
}

void main ( void ) 
{
    application_init( );

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

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

Additional Support

Resources