Experience a new era of brushless motor control with L6235 and ATmega328P
Achieve optimal performance effortlessly
Published Feb 14, 2024
Click board™
Brushless 12 Click
Dev. board
Arduino UNO Rev3
Compiler
NECTO Studio
MCU
ATmega328P
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.
Features overview
Development board
Arduino UNO is a versatile microcontroller board built around the ATmega328P chip. It offers extensive connectivity options for various projects, featuring 14 digital input/output pins, six of which are PWM-capable, along with six analog inputs. Its core components include a 16MHz ceramic resonator, a USB connection, a power jack, an
ICSP header, and a reset button, providing everything necessary to power and program the board. The Uno is ready to go, whether connected to a computer via USB or powered by an AC-to-DC adapter or battery. As the first USB Arduino board, it serves as the benchmark for the Arduino platform, with "Uno" symbolizing its status as the
first in a series. This name choice, meaning "one" in Italian, commemorates the launch of Arduino Software (IDE) 1.0. Initially introduced alongside version 1.0 of the Arduino Software (IDE), the Uno has since become the foundational model for subsequent Arduino releases, embodying the platform's evolution.
Microcontroller Overview
MCU Card / MCU
Architecture
AVR
MCU Memory (KB)
32
Silicon Vendor
Microchip
Pin count
28
RAM (Bytes)
2048
You complete me!
Accessories
Click Shield for Arduino UNO has two proprietary mikroBUS™ sockets, allowing all the Click board™ devices to be interfaced with the Arduino UNO board without effort. The Arduino Uno, a microcontroller board based on the ATmega328P, provides an affordable and flexible way for users to try out new concepts and build prototypes with the ATmega328P microcontroller from various combinations of performance, power consumption, and features. The Arduino Uno has 14 digital input/output pins (of which six can be used as PWM outputs), six analog inputs, a 16 MHz ceramic resonator (CSTCE16M0V53-R0), a USB connection, a power jack, an ICSP header, and reset button. Most of the ATmega328P microcontroller pins are brought to the IO pins on the left and right edge of the board, which are then connected to two existing mikroBUS™ sockets. This Click Shield also has several switches that perform functions such as selecting the logic levels of analog signals on mikroBUS™ sockets and selecting logic voltage levels of the mikroBUS™ sockets themselves. Besides, the user is offered the possibility of using any Click board™ with the help of existing bidirectional level-shifting voltage translators, regardless of whether the Click board™ operates at a 3.3V or 5V logic voltage level. Once you connect the Arduino UNO board with our Click Shield for Arduino UNO, you can access hundreds of Click boards™, working with 3.3V or 5V logic voltage levels.
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.
Used MCU Pins
mikroBUS™ mapper
Take a closer look
Click board™ Schematic
Step by step
Project assembly
Start by selecting your development board and Click board™. Begin with the Arduino UNO Rev3 as your development board.
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 Brushless 12 Click driver.
Key functions:
brushless12_set_brake- This function sets the BRK pin to the desired statebrushless12_set_direction- This function sets the F/R pin to the desired statebrushless12_set_enable- This function sets the EN pin to the desired 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 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 ( 1000 );
Delay_ms ( 1000 );
Delay_ms ( 1000 );
Delay_ms ( 1000 );
Delay_ms ( 1000 );
log_printf( &logger, "Pull brake! \r\n" );
brushless12_set_brake ( &brushless12, BRUSHLESS12_BRAKE );
Delay_ms ( 1000 );
Delay_ms ( 1000 );
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 ( 1000 );
Delay_ms ( 1000 );
Delay_ms ( 1000 );
Delay_ms ( 1000 );
Delay_ms ( 1000 );
log_printf( &logger, "Pull brake! \r\n" );
brushless12_set_brake ( &brushless12, BRUSHLESS12_BRAKE );
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
Category:Brushless
