Master motor speed control with Si8711CC and STM32L496AG

PWM precision meets motor control

PWM driver Click with Discovery kit with STM32L496AG MCU

Published Jul 22, 2025

Click board™

PWM driver Click

Dev. board

Discovery kit with STM32L496AG MCU

Compiler

NECTO Studio

MCU

STM32L496AG

Unlock speed control possibilities with our PWM-controlled DC motor solution

Hardware Overview

How does it work?

PWM driver Click is based on the Si8711CC, a 5kV LED emulator input, open collector output isolator from Skyworks. Compared to the optocouplers, the Si8711CC is more resistant to temperature, age, and forward current effects. It has a longer service life, higher common-mode transient immunity, and more. The Si8711CC is based on proprietary CMOS isolation technology for low-power, high-speed operation and is resistant to wear-out effects that, in the case of optocouplers, degrade the performance. The Si8711CC features up to 5000VRMS isolation and 10kV surge protection, making it a perfect isolator. For controlling the devices, it is capable of data rates DC of up to 15Mbps, with a propagation delay of 30ns. The Si8711CC controls the loads over the DMP3010LK3,

a P-channel enhancement mode MOSFET from Diodes Incorporated. This fast-switching diode has ESD protected gate, low input capacitance, and low on-resistance, designed to maintain superior switching performance, making it ideal for high-efficiency power management applications. The PWM Driver Click comes with the screw terminals labeled LOAD (+END, -END) to connect the load, which the Si7811CC controls over the DMP3010LK3 diode, and EXT for external power supply. It is not recommended to use this Click board™ with loads over 50W as the MOSFET can get overheated; this, however, does not apply if the Click board™ is used as an ON/OFF switch. The PWM Driver Click is controlled by the host MCU by PWM pulses over the PWM pin of the mikroBUS™ socket. The PWM

pin does not have direct control over the Si8711CC but rather through the DMG3420U, an N-channel enhancement mode MOSFET from Diodes Incorporated. This diode shares many features with the one mentioned above, such as low on-resistance, low input capacitance, fast switching speed, and more. 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. However, the Click board™ comes equipped with a library containing functions and an example code that can be used, as a reference, for further development.

PWM driver Click hardware overview image

Features overview

Development board

The 32L496GDISCOVERY Discovery kit serves as a comprehensive demonstration and development platform for the STM32L496AG microcontroller, featuring an Arm® Cortex®-M4 core. Designed for applications that demand a balance of high performance, advanced graphics, and ultra-low power consumption, this kit enables seamless prototyping for a wide range of embedded solutions. With its innovative energy-efficient

architecture, the STM32L496AG integrates extended RAM and the Chrom-ART Accelerator, enhancing graphics performance while maintaining low power consumption. This makes the kit particularly well-suited for applications involving audio processing, graphical user interfaces, and real-time data acquisition, where energy efficiency is a key requirement. For ease of development, the board includes an onboard ST-LINK/V2-1

debugger/programmer, providing a seamless out-of-the-box experience for loading, debugging, and testing applications without requiring additional hardware. The combination of low power features, enhanced memory capabilities, and built-in debugging tools makes the 32L496GDISCOVERY kit an ideal choice for prototyping advanced embedded systems with state-of-the-art energy efficiency.

Discovery kit with STM32L496AG MCU double side image

Microcontroller Overview

MCU Card / MCU

Architecture

ARM Cortex-M4

MCU Memory (KB)

1024

Silicon Vendor

STMicroelectronics

Pin count

169

RAM (Bytes)

327680

Used MCU Pins

mikroBUS™ mapper

RST

SCK

MISO

MOSI

3.3V

Ground

GND

PWM Control

PA0

PWM

INT

SCL

SDA

Power Supply

Ground

GND

Take a closer look

Click board™ Schematic

Step by step

Project assembly

Discovery kit with STM32H750XB MCU front image hardware assembly

Start by selecting your development board and Click board™. Begin with the Discovery kit with STM32L496AG MCU as your development board.

Thermo 21 Click front image hardware assembly

Thermo 21 Click complete accessories setup image hardware assembly

Board mapper by product7 hardware assembly

Discovery kit with STM32H750XB MCU NECTO MCU Selection Step hardware assembly

Necto No Display image step 8 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 PWM driver Click driver.

Key functions:

pwmdriver_set_duty_cycle - Generic sets PWM duty cycle
pwmdriver_pwm_stop - Stop PWM module
pwmdriver_pwm_start - Start PWM module

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 PwmDriver Click example
 * 
 * # Description
 * This application is controls the speed DC motors.
 *
 * The demo application is composed of two sections :
 * 
 * ## Application Init 
 * Initialization driver enables - GPIO, PWM initialization set PWM duty cycle and PWM frequency,
 * start PWM, enable the engine, and start to write log.
 * 
 * ## Application Task  
 * This is an example that demonstrates the use of the PWM driver Click board.
 * This example shows the automatic control of PWM,
 * the first increases duty cycle and then the duty cycle is falling.
 * Results are being sent to the Usart Terminal where you can track their changes.
 * 
 * *note:* 
 * EXT PWR 3-30VDC
 * 
 * @author Nikola Peric
 *
 */
// ------------------------------------------------------------------- INCLUDES

#include "board.h"
#include "log.h"
#include "pwmdriver.h"

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

static pwmdriver_t pwmdriver;
static log_t logger;

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

void application_init ( void )
{
    log_cfg_t log_cfg;
    pwmdriver_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.

    pwmdriver_cfg_setup( &cfg );
    PWMDRIVER_MAP_MIKROBUS( cfg, MIKROBUS_1 );
    pwmdriver_init( &pwmdriver, &cfg );
    Delay_ms ( 100 );
    
    log_printf( &logger, "   Initialization PWM  \r\n  " );
    pwmdriver_set_duty_cycle( &pwmdriver, 0.0 );
    pwmdriver_pwm_start( &pwmdriver );
    Delay_ms ( 1000 );
    log_info( &logger, "---- Application Task ----" );
}

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

    pwmdriver_set_duty_cycle ( &pwmdriver, 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;
    }
    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