Beginner
10 min
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Make projects more interactive and visually appealing with TLC5925 and dsPIC33FJ256GP710A

Orange LED ring for a visual representation of the knob's position

Rotary O 2 Click with EasyPIC Fusion v7

Published Dec 21, 2023

Click board™

Rotary O 2 Click

Development board

EasyPIC Fusion v7

Compiler

NECTO Studio

MCU

dsPIC33FJ256GP710A

Enhance your projects with a visually engaging and informative LED ring, adding both style and functionality to your device

A

A

Hardware Overview

How does it work?

Rotary O 2 Click is based on the TLC5925, a low-power 16-channel constant-current LED sink driver from Texas Instruments that, combined with a high-quality rotary encoder from ALPS, the EC12D1564402, allows you to add a precision input knob to your design. The EC12D1564402 incremental rotary encoder is surrounded by a ring of 16 orange LEDs where a single rotation is divided into 15 discrete steps (in contrast to a potentiometer, a rotary encoder can be spun around continuously). The driver can control each LED individually, allowing various lighting effects to be programmed. The encoder outputs A and B signals (out of phase to each other) on the two mikroBUS™ lines, alongside the knob push-button

feature, which outputs through the interrupt line. The EC12D1564402 is a 15-pulse incremental rotary encoder with a push button. This encoder has unique mechanical specifications (debouncing time for its internal switches goes down to 2ms), and it can withstand a huge number of switching cycles, up to 30.000. The supporting debouncing circuitry allows contacts to settle before the output is triggered fully. Rotary O 2 Click uses a standard 4-wire SPI serial interface of the TLC5925 LED driver to communicate with the host MCU supporting clock frequency of up to 30MHz. Rotating the encoder, it outputs A and B signals (out of phase to each other) on the two mikroBUS™ lines, ENA and ENB pins of the

mikroBUS™ socket, alongside the push-button contact, which outputs through the SW pin (interrupt line) of the mikroBUS™ socket. Two SN74LVC1T45 single-bit bus transceivers from Texas Instruments are used for logic-level translation. This Click board™ can operate with either 3.3V or 5V logic voltage levels selected via the VCC SEL jumper. This way, both 3.3V and 5V capable MCUs can use the communication lines properly. Also, this Click board™ comes equipped with a library containing easy-to-use functions and an example code that can be used as a reference for further development.

Rotary O 2 Click hardware overview image

Features overview

Development board

EasyPIC Fusion v7 is the seventh generation of PIC development boards specially designed to develop embedded applications rapidly. It supports a wide range of 16/32-bit PIC microcontrollers from Microchip and 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, such as switches, buttons, indicators, connectors, and others, in one place. With two different connectors for each port, EasyPIC Fusion v7 allows you to connect accessory boards, sensors, and custom electronics more efficiently than ever. Each part of

the EasyPIC Fusion 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 a wide range of external power sources, including an external 12V power supply, 7-12V AC or 9-15V DC via DC connector/screw terminals, and a power source via the USB Type-B (USB-B) connector. Communication options such

as USB-UART, USB-HOST, CAN, and Ethernet are also included, including the well-established mikroBUS™ standard, one display option for the TFT board line of products, and a standard TQFP socket for the seventh-generation MCU cards. This socket covers a wide range of 16-bit dsPIC/PIC24 and 32-bit PIC32 MCUs. EasyPIC Fusion 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 Fusion v7 horizontal image

Microcontroller Overview

MCU Card / MCU

default

Type

7th Generation

Architecture

dsPIC

MCU Memory (KB)

256

Silicon Vendor

Microchip

Pin count

100

RAM (Bytes)

30720

Used MCU Pins

mikroBUS™ mapper

Encoder Output B
RB8
AN
ID SEL
RC1
RST
SPI Select / ID COMM
RC2
CS
SPI Clock
RD15
SCK
SPI Data OUT
RF2
MISO
SPI Data IN
RF8
MOSI
Power Supply
3.3V
3.3V
Ground
GND
GND
Encoder Output A
RD0
PWM
Output Switch
RE8
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

Rotary O 2 Click Schematic schematic

Step by step

Project assembly

EasyPIC Fusion v7 front image hardware assembly

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

EasyPIC Fusion v7 front image hardware assembly
GNSS2 Click front image hardware assembly
EasyPIC FUSION v7 ETH MCUcard with PIC32MZ2048EFH144 front image hardware assembly
GNSS2 Click complete accessories setup image hardware assembly
EMxPRO-STM32-TIVA/EPIC Fusion 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
EasyPIC PRO v7a MCU Selection Necto Step 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 Rotary O 2 Click driver.

Key functions:

  • rotaryo2_set_led_pos - This function turns on the LED for the selected LED position.

  • rotaryo2_set_led_data - This function, using SPI serial interface, writes a desired 16-bit data.

  • rotaryo2_get_state_switch - This function return rotary encoder switch signal, states of the SW(INT).

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 Rotary O 2 Click example
 *
 * # Description
 * This library contains the API for the Rotary O 2 Click driver 
 * to control LEDs states and a rotary encoder position readings.
 *
 * The demo application is composed of two sections :
 *
 * ## Application Init
 * Initialization of SPI module and log UART.
 * After the driver init, the app executes a default configuration and turn off all LEDs.
 *
 * ## Application Task
 * This example demonstrates the use of the Rotary O 2 Click board?.
 * The demo example shows the functionality of a rotary encoder used to control LEDs.
 *
 * @author Nenad Filipovic
 *
 */

#include "board.h"
#include "log.h"
#include "rotaryo2.h"

#define ROTARYO2_ONE_LED          ROTARYO2_SET_LED_DATA_1
#define ROTARYO2_TWO_LED          ROTARYO2_SET_LED_DATA_1  | ROTARYO2_SET_LED_DATA_9
#define ROTARYO2_FOUR_LED         ROTARYO2_SET_LED_DATA_1  | ROTARYO2_SET_LED_DATA_5  | \
                                  ROTARYO2_SET_LED_DATA_9  | ROTARYO2_SET_LED_DATA_13 
#define ROTARYO2_EIGHT_LED        ROTARYO2_SET_LED_DATA_1  | ROTARYO2_SET_LED_DATA_3  | \
                                  ROTARYO2_SET_LED_DATA_5  | ROTARYO2_SET_LED_DATA_7  | \
                                  ROTARYO2_SET_LED_DATA_9  | ROTARYO2_SET_LED_DATA_11 | \
                                  ROTARYO2_SET_LED_DATA_13 | ROTARYO2_SET_LED_DATA_15
#define ROTARYO2_EIGHT_LED_INV    ROTARYO2_SET_LED_DATA_2  | ROTARYO2_SET_LED_DATA_4  | \
                                  ROTARYO2_SET_LED_DATA_6  | ROTARYO2_SET_LED_DATA_8  | \
                                  ROTARYO2_SET_LED_DATA_10 | ROTARYO2_SET_LED_DATA_12 | \
                                  ROTARYO2_SET_LED_DATA_14 | ROTARYO2_SET_LED_DATA_16

static rotaryo2_t rotaryo2;
static log_t logger;

static uint8_t start_rot_status = 0;
static uint8_t led_demo_state = 0;
static uint8_t old_state = 0;
static uint8_t new_state = 1;
static uint8_t old_rot_state = 0;
static uint8_t new_rot_state = 1;
static uint16_t led_data = 1;

/**
 * @brief Rotary O 2 select LED demo data function.
 * @details This function selects one of the four LED demo data 
 * based on the current state of the LED demo.
 * @return LED demo data:
 *         @li @c 0x0001 (ROTARYO2_ONE_LED)   - Turn ON LED[1],
 *         @li @c 0x0101 (ROTARYO2_TWO_LED)   - Turn ON LED[1,9],
 *         @li @c 0x0101 (ROTARYO2_FOUR_LED)  - Turn ON LED[1,5,9,13],
 *         @li @c 0x5555 (ROTARYO2_EIGHT_LED) - Turn ON LED[1,3,5,7,9,11,13,15].
 */
static uint16_t rotaryo2_sel_led_demo_data ( uint8_t led_demo_state );

/**
 * @brief Rotary O 2 switch detection function.
 * @details This function is used for the switch state detection.
 * @return Nothing.
 */
static void rotaryo2_switch_detection ( void );

/**
 * @brief Rotary O 2 encoder mechanism function.
 * @details This function is used to control the state of the LEDs 
 * by detecting the rotation direction of the rotary encoder.
 * @return Nothing.
 */
static void rotaryo2_encoder_mechanism ( void );

void application_init ( void )
{
    log_cfg_t log_cfg;  /**< Logger config object. */
    rotaryo2_cfg_t rotaryo2_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.
    rotaryo2_cfg_setup( &rotaryo2_cfg );
    ROTARYO2_MAP_MIKROBUS( rotaryo2_cfg, MIKROBUS_1 );
    if ( SPI_MASTER_ERROR == rotaryo2_init( &rotaryo2, &rotaryo2_cfg ) )
    {
        log_error( &logger, " Communication init." );
        for ( ; ; );
    }
    
    if ( ROTARYO2_ERROR == rotaryo2_default_cfg ( &rotaryo2 ) )
    {
        log_error( &logger, " Default configuration." );
        for ( ; ; );
    }
    
    log_info( &logger, " Application Task " );
}

void application_task ( void )
{
    if ( ROTARYO2_OK == rotaryo2_set_led_data( &rotaryo2, led_data ) )
    {
        rotaryo2_switch_detection( );
        rotaryo2_encoder_mechanism( );
    }
}

void main ( void )
{
    application_init( );

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

static uint16_t rotaryo2_sel_led_demo_data ( uint8_t led_demo_state ) 
{
    switch ( led_demo_state ) 
    {
        case 0: 
        {
            return ROTARYO2_ONE_LED;
            break;
        }
        case 1: 
        {
            return ROTARYO2_TWO_LED;
            break;
        }
        case 2: 
        {
            return ROTARYO2_FOUR_LED;
            break;
        }
        case 3: 
        {
            return ROTARYO2_EIGHT_LED;
            break;
        }
        default: 
        {
            return ROTARYO2_ONE_LED;
            break;
        }
    }
}

static void rotaryo2_switch_detection ( void )
{
    if ( rotaryo2_get_state_switch( &rotaryo2 ) ) 
    {
        new_state = 1;
        if ( (  1 == new_state ) && ( 0 == old_state ) ) 
        {
            old_state = 1;
            led_demo_state = ( led_demo_state + 1 ) % 5;
            if ( 4 == led_demo_state ) 
            {
                for ( uint8_t n_cnt = 0; n_cnt < 10; n_cnt++ )
                {
                    rotaryo2_set_led_data( &rotaryo2, ROTARYO2_EIGHT_LED_INV );
                    Delay_ms( 100 );
                    rotaryo2_set_led_data( &rotaryo2, ROTARYO2_EIGHT_LED );
                    Delay_ms( 100 );
                }
                
                for ( uint8_t led_p = ROTARYO2_SET_LED_POS_1; led_p <= ROTARYO2_SET_LED_POS_16; led_p++ ) 
                {
                    rotaryo2_set_led_pos( &rotaryo2, led_p );
                    Delay_ms( 100 );
                }
                
                led_demo_state = 0;
                led_data = rotaryo2_sel_led_demo_data( led_demo_state );
            }
            else 
            {
                led_data = rotaryo2_sel_led_demo_data( led_demo_state );
            }
        }
    }
    else 
    {
        old_state = 0;
    }
}

static void rotaryo2_encoder_mechanism ( void )
{
    if ( rotaryo2_get_state_ena( &rotaryo2 ) == rotaryo2_get_state_enb( &rotaryo2 ) ) 
    {
        old_rot_state = 0;
        start_rot_status = rotaryo2_get_state_ena( &rotaryo2 ) && rotaryo2_get_state_enb( &rotaryo2 );
    }
    else 
    {
        new_rot_state = 1;
        if ( new_rot_state != old_rot_state ) 
        {
            old_rot_state = 1;
            if ( start_rot_status != rotaryo2_get_state_ena( &rotaryo2 ) ) 
            {
                led_data = ( led_data << 1 ) | ( led_data >> 15 );
            }
            else 
            {
                led_data = ( led_data >> 1 ) | ( led_data << 15 );
            }
        }
    }
}

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

Additional Support

Resources