Intermediate
30 min
0

Enhance user experiences with advanced ERM motor control based on C1026B002F and PIC18F2685

Sync and thrive!

Vibro Motor Click with EasyPIC v7a

Published Nov 01, 2023

Click board™

Vibro Motor Click

Development board

EasyPIC v7a

Compiler

NECTO Studio

MCU

PIC18F2685

In today's dynamic landscape of vibrational applications, our solution aims to simplify motor control and enhance vibrational experiences, offering a user-friendly way to manage ERM motors

A

A

Hardware Overview

How does it work?

Vibro Motor Click is based on the C1026B002F, a compact-size Eccentric Rotating Mass (ERM) motor. This type of motor is often used for haptic feedback on many small handheld devices, such as cellphones, pagers, RFID scanners, and similar devices. This motor contains a small eccentric weight on its rotor, so it also produces a vibration effect while rotating. This kind of motor is sometimes called a coin motor due to its shape. Besides the vibration motor, the click is also equipped with the DMG3420U, a small MOSFET used to drive the motor. The Vibro Motor click is ideal for adding simple, one-pin-driven haptic feedback on any design. The circuit also contains

a protection diode, which protects the transistor from the reverse voltage since the motor represents an inductive load, and turning off its current can produce a kickback voltage that can damage the transistor. The gate of the MOSFET is driven by the PWM signal, routed through the PWM pin of the mikroBUS™. The PWM signal toggles the gate of the MOSFET with pulses of a certain width. As a result, the current through the motor is varied depending on the pulse width of the PWM signal, which directly affects the speed of the motor, effectively controlling the vibration force that way. The small, eccentric weight attached to the rotor of the coin motor generates

the centrifugal force while it rotates, which in turn results in the wobbling effect of the motor itself. The faster the rotation is, the bigger the force gets. Controlling the motor speed allows for the vibration intensity to be controlled. This Click board™ can be operated only with a 3.3V logic voltage level. The board must perform appropriate logic voltage level conversion before using MCUs with different logic levels. Also, it comes equipped with a library containing functions and an example code that can be used as a reference for further development.

Vibro Motor Click top side image
Vibro Motor Click bottom side image

Features overview

Development board

EasyPIC v7a is the seventh generation of PIC development boards specially designed for the needs of rapid development of embedded applications. It supports a wide range of 8-bit PIC microcontrollers from Microchip and has a broad set of unique functions, such as the first-ever embedded debugger/programmer over USB-C. 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 v7a allows you to connect accessory boards, sensors, and custom electronics more efficiently than ever. Each part of the EasyPIC v7a development board

contains the components necessary for the most efficient operation of the same board. In addition to the advanced integrated CODEGRIP programmer/debugger module, which offers many valuable programming/debugging options and seamless integration with the Mikroe software environment, the board also includes a clean and regulated power supply module 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-C (USB-C) 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 v7a 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 v7a double side image

Microcontroller Overview

MCU Card / MCU

default

Architecture

PIC

MCU Memory (KB)

96

Silicon Vendor

Microchip

Pin count

28

RAM (Bytes)

3328

Used MCU Pins

mikroBUS™ mapper

NC
NC
AN
NC
NC
RST
NC
NC
CS
NC
NC
SCK
NC
NC
MISO
NC
NC
MOSI
Power Supply
3.3V
3.3V
Ground
GND
GND
Motor Speed Control
RC1
PWM
NC
NC
INT
NC
NC
TX
NC
NC
RX
NC
NC
SCL
NC
NC
SDA
NC
NC
5V
Ground
GND
GND
2

Take a closer look

Schematic

Vibro Motor Click Schematic schematic

Step by step

Project assembly

EasyPIC v7a front image hardware assembly

Start by selecting your development board and Click board™. Begin with the EasyPIC v7a as your development board.

EasyPIC v7a front image hardware assembly
Rotary B 2 Click front image hardware assembly
MCU DIP 28 hardware assembly
EasyPIC v7a MB 2 - 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 Vibro Motor Click driver.

Key functions:

  • vibromotor_set_duty_cycle - This function sets the PWM duty cycle in percentages ( Range[ 0..1 ] )

  • vibromotor_pwm_stop - This function stops the PWM moudle output

  • vibromotor_pwm_start - This function starts the PWM moudle output.

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 VibroMotor Click example
 *
 * # Description
 * This application contorl the speed of vibro motor.
 *
 * The demo application is composed of two sections :
 * 
 * ## Application Init 
 * Initializes GPIO driver and PWM.
 * Configures PWM to 5kHz frequency, calculates maximum duty ratio and starts PWM 
 * with duty ratio value 0.
 * 
 * ## Application Task  
 * Allows user to enter desired command to control
 * Vibro Motor Click board.
 *
 * @author Stefan Ilic
 *
 */

#include "board.h"
#include "log.h"
#include "vibromotor.h"


static vibromotor_t vibromotor;
static log_t logger;

void application_init ( void ) {
    log_cfg_t log_cfg;  /**< Logger config object. */
    vibromotor_cfg_t vibromotor_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.

    vibromotor_cfg_setup( &vibromotor_cfg );
    VIBROMOTOR_MAP_MIKROBUS( vibromotor_cfg, MIKROBUS_1 );
    err_t init_flag  = vibromotor_init( &vibromotor, &vibromotor_cfg );
    if ( PWM_ERROR == init_flag ) {
        log_error( &logger, " Application Init Error. " );
        log_info( &logger, " Please, run program again... " );

        for ( ; ; );
    }

    vibromotor_set_duty_cycle ( &vibromotor, 0.0 );
    vibromotor_pwm_start( &vibromotor );

    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;
    
    vibromotor_set_duty_cycle ( &vibromotor, 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

Additional Support

Resources