Master motor speed control with Si8711CC and PIC18F47K42TQFP
PWM precision meets motor control
Published Feb 13, 2024
Click board™
PWM driver Click
Dev Board
Curiosity Nano with PIC18F47K42
Compiler
NECTO Studio
MCU
PIC18F47K42TQFP
Unlock speed control possibilities with our PWM-controlled DC motor solution
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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.
Features overview
Development board
PIC18F47K42 Curiosity Nano evaluation kit is a cutting-edge hardware platform designed to evaluate the PIC18F47K42 microcontroller (MCU). Central to its design is the inclusion of the powerful PIC18F47K42 microcontroller (MCU), offering advanced functionalities and robust performance. Key features of this evaluation kit include a yellow user LED and a responsive mechanical user switch
providing seamless interaction and testing. The provision for a 32.768kHz crystal footprint ensures precision timing capabilities. With an onboard debugger boasting a green power and status LED, programming and debugging become intuitive and efficient. Further enhancing its utility is the Virtual serial port (CDC) and a debug GPIO channel (DGI GPIO), offering extensive connectivity options.
Powered via USB, this kit boasts an adjustable target voltage feature facilitated by the MIC5353 LDO regulator, ensuring stable operation with an output voltage ranging from 2.3V to 5.1V (limited by USB input voltage), with a maximum output current of 500mA, subject to ambient temperature and voltage constraints.
Microcontroller Overview
MCU Card / MCU
Architecture
PIC
MCU Memory (KB)
128
Silicon Vendor
Microchip
Pin count
40
RAM (Bytes)
8192
You complete me!
Accessories
Curiosity Nano Base for Click boards is a versatile hardware extension platform created to streamline the integration between Curiosity Nano kits and extension boards, tailored explicitly for the mikroBUS™-standardized Click boards and Xplained Pro extension boards. This innovative base board (shield) offers seamless connectivity and expansion possibilities, simplifying experimentation and development. Key features include USB power compatibility from the Curiosity Nano kit, alongside an alternative external power input option for enhanced flexibility. The onboard Li-Ion/LiPo charger and management circuit ensure smooth operation for battery-powered applications, simplifying usage and management. Moreover, the base incorporates a fixed 3.3V PSU dedicated to target and mikroBUS™ power rails, alongside a fixed 5.0V boost converter catering to 5V power rails of mikroBUS™ sockets, providing stable power delivery for various connected devices.
Used MCU Pins
mikroBUS™ mapper
Take a closer look
Schematic
Step by step
Project assembly
Start by selecting your development board and Click board™. Begin with the Curiosity Nano with PIC18F47K42 as your development board.
Track your results in real time
Application Output via Debug Mode
1. Once the code example is loaded, pressing the "DEBUG" button initiates the build process, programs it on the created setup, and enters Debug mode.
2. After the programming is completed, a header with buttons for various actions within the IDE becomes visible. Clicking the green "PLAY" button starts reading the results achieved with the Click board™. The achieved results are displayed in the Application Output tab.
Software Support
Library Description
This library contains API for PWM driver Click driver.
Key functions:
pwmdriver_set_duty_cycle- Generic sets PWM duty cyclepwmdriver_pwm_stop- Stop PWM modulepwmdriver_pwm_start- Start PWM module
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
* @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;
}
void main ( void )
{
application_init( );
for ( ; ; )
{
application_task( );
}
}
// ------------------------------------------------------------------------ END
