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Achieve safety isolation from high voltage with ISOM8710 and PIC18F86J50

High voltage, low worries

Opto 7 Click with UNI-DS v8

Published Dec 19, 2023

Click board™

Opto 7 Click

Development board

UNI-DS v8

Compiler

NECTO Studio

MCU

PIC18F86J50

Safety shield that you can add to electronic systems, especially in applications like power supplies, electricity meters, motor drives, and automation systems

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Hardware Overview

How does it work?

Opto 7 Click is based on two ISOM8710s, high-speed single-channel opto-emulators from Texas Instruments. It can transmit data rates of up to 25Mbps and output 3.3V and 5V signals with a CMOS-compatible output. Compared to an optocoupler, the ISOM7810 has a high common mode transient immunity, low propagation delay, small pulse with distortion, low power consumption, and more. Opto 7 Click is equipped with two of these opto-emulators for receiving and transmitting

data. The external power supply can be connected to a VCC2 terminal and must be 3.3V or 5V. The three-pin terminal connects input and output data lines along with the common ground. Opto 7 Click can use general-purpose IO to communicate with the host MCU over the GP1 and GP2 pins. It can also be used for a standard UART communication isolation with commonly used UART RX and TX pins. The selection can be made over the OUT SEL and IN SEL jumpers. Both should be in a proper

position for the communication to work. 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.

Opto 7 Click hardware overview image

Features overview

Development board

UNI-DS v8 is a development board specially designed for the needs of rapid development of embedded applications. It supports a wide range of microcontrollers, such as different STM32, Kinetis, TIVA, CEC, MSP, PIC, dsPIC, PIC32, and AVR MCUs regardless of their number of pins, and a broad set of unique functions, such as the first-ever embedded debugger/programmer over WiFi. 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. Thanks to innovative manufacturing technology, UNI-DS v8 provides a fluid and immersive working experience, allowing access anywhere and under any

circumstances at any time. Each part of the UNI-DS v8 development board contains the components necessary for the most efficient operation of the same board. An advanced integrated CODEGRIP programmer/debugger module offers many valuable programming/debugging options, including support for JTAG, SWD, and SWO Trace (Single Wire Output)), and seamless integration with the Mikroe software environment. Besides, it also includes a clean and regulated power supply module for the development board. It can use a wide range of external power sources, including a battery, an external 12V power supply, and a power source via the USB Type-C (USB-C) connector. Communication options such as USB-UART, USB

HOST/DEVICE, CAN (on the MCU card, if supported), and Ethernet is also included. In addition, it also has the well-established mikroBUS™ standard, a standardized socket for the MCU card (SiBRAIN standard), and two display options for the TFT board line of products and character-based LCD. UNI-DS v8 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.

UNI-DS v8 horizontal image

Microcontroller Overview

MCU Card / MCU

default

Type

8th Generation

Architecture

PIC

MCU Memory (KB)

64

Silicon Vendor

Microchip

Pin count

80

RAM (Bytes)

3904

Used MCU Pins

mikroBUS™ mapper

NC
NC
AN
NC
NC
RST
ID COMM
PJ0
CS
NC
NC
SCK
NC
NC
MISO
NC
NC
MOSI
Power Supply
3.3V
3.3V
Ground
GND
GND
General-Purpose I/O
PE0
PWM
General-Purpose I/O
PB0
INT
UART TX
PG1
TX
UART RX
PG2
RX
NC
NC
SCL
NC
NC
SDA
Power Supply
5V
5V
Ground
GND
GND
1

Take a closer look

Schematic

Opto 7 Click Schematic schematic

Step by step

Project assembly

Fusion for PIC v8 front image hardware assembly

Start by selecting your development board and Click board™. Begin with the UNI-DS v8 as your development board.

Fusion for PIC v8 front image hardware assembly
GNSS2 Click front image hardware assembly
SiBRAIN for PIC32MZ1024EFK144 front image hardware assembly
GNSS2 Click complete accessories setup image hardware assembly
v8 SiBRAIN 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
Necto image step 7 hardware assembly
Necto image step 8 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 Opto 7 Click driver.

Key functions:

  • opto7_generic_write - Opto 7 data writing function.

  • opto7_set_gp1_pin - Opto 7 set GP1 pin function.

  • opto7_get_gp2_pin - Opto 7 get GP2 pin function.

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 Opto 7 Click Example.
 *
 * # Description
 * This example demonstrates the use of Opto 7 click board by processing
 * the incoming data and displaying them on the USB UART.
 *
 * The demo application is composed of two sections :
 *
 * ## Application Init
 * Initialization of UART LOG and GPIO pin, and UART drivers.
 *
 * ## Application Task
 * This example is made of two parts:
 * GPIO Example - The output pin is toggled every 5 seconds and input pin state is being tracked.
 * UART Example - Device assigned as transmitter is sending message and receiver is reading it and displaying it on USB UART.
 * 
 * ## Additional Function
 * - static void opto7_clear_app_buf ( void )
 * - static void opto7_log_app_buf ( void )
 * - static err_t opto7_process ( opto7_t *ctx )
 * 
 * @author Stefan Ilic
 *
 */

#include "board.h"
#include "log.h"
#include "opto7.h"

// Example selection macros
#define EXAMPLE_GPIO                1               // Example of using GPIO
#define EXAMPLE_UART                2               // Example of using UART
#define DEMO_EXAMPLE                EXAMPLE_GPIO    // Example selection macro

// Macros for UART example
#define TRANSMITTER                 // Comment out this line to place device into receiver mode
#define TX_MESSAGE                  "Opto 7 Click Example \r\n"

// Application buffer size
#define APP_BUFFER_SIZE             500
#define PROCESS_BUFFER_SIZE         200

static opto7_t opto7;
static log_t logger;


static uint8_t app_buf[ APP_BUFFER_SIZE ] = { 0 };
static int32_t app_buf_len = 0;

/**
 * @brief Test clearing application buffer.
 * @details This function clears memory of application buffer and reset its length.
 * @note None.
 */
static void opto7_clear_app_buf ( void );

/**
 * @brief Test log application buffer.
 * @details This function logs data from application buffer to USB UART.
 * @note None.
 */
static void opto7_log_app_buf ( void );

/**
 * @brief Test data reading function.
 * @details This function reads data from device and concatenates data to application buffer. 
 * @param[in] ctx : Click context object.
 * See #opto7_t object definition for detailed explanation.
 * @return @li @c  0 - Read some data.
 *         @li @c -1 - Nothing is read.
 * See #err_t definition for detailed explanation.
 * @note None.
 */
static err_t opto7_process ( opto7_t *ctx );

void application_init ( void ) 
{
    log_cfg_t log_cfg;  /**< Logger config object. */
    opto7_cfg_t opto7_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.
    opto7_cfg_setup( &opto7_cfg );
    OPTO7_MAP_MIKROBUS( opto7_cfg, MIKROBUS_1 );
    
#if ( DEMO_EXAMPLE == EXAMPLE_GPIO )
    opto7_drv_interface_selection( &opto7_cfg, OPTO7_DRV_SEL_GPIO );
#else
    opto7_drv_interface_selection( &opto7_cfg, OPTO7_DRV_SEL_UART );
#endif
    
    if ( UART_ERROR == opto7_init( &opto7, &opto7_cfg ) ) 
    {
        log_error( &logger, " Communication init." );
        for ( ; ; );
    }
    
    log_info( &logger, " Application Task " );
}

void application_task ( void ) 
{
#if ( DEMO_EXAMPLE == EXAMPLE_GPIO )
    log_printf( &logger, " GP1 pin state HIGH \r\n" );
    opto7_set_gp1_pin( &opto7, OPTO7_PIN_STATE_HIGH );
     if ( OPTO7_PIN_STATE_HIGH == opto7_get_gp2_pin( &opto7 ) )
    {
        log_printf( &logger, " GP2 pin state HIGH \r\n" );
    }
    else
    {
        log_printf( &logger, " GP2 pin state LOW \r\n" );
    }
    log_printf( &logger, "- - - - - - - - - - - -\r\n" );
    Delay_ms( 5000 );
    
    log_printf( &logger, " GP1 pin state LOW \r\n" );
    opto7_set_gp1_pin( &opto7, OPTO7_PIN_STATE_LOW );
    if ( OPTO7_PIN_STATE_HIGH == opto7_get_gp2_pin( &opto7 ) )
    {
        log_printf( &logger, " GP2 pin state HIGH \r\n" );
    }
    else
    {
        log_printf( &logger, " GP2 pin state LOW \r\n" );
    }
    log_printf( &logger, "- - - - - - - - - - - -\r\n" );
    Delay_ms( 5000 );
#else
#if defined TRANSMITTER
    log_printf( &logger, " Message sent! \r\n" );
    opto7_generic_write( &opto7, TX_MESSAGE, strlen( TX_MESSAGE ) );
    Delay_ms( 2000 );
#else
    if ( OPTO7_OK == opto7_process( &opto7 ) ) 
    {
        opto7_log_app_buf( );
        opto7_clear_app_buf( );
    }
#endif

#endif
}

void main ( void ) 
{
    application_init( );

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

static void opto7_clear_app_buf ( void ) 
{
    memset( app_buf, 0, app_buf_len );
    app_buf_len = 0;
}

static void opto7_log_app_buf ( void )
{
    for ( int32_t buf_cnt = 0; buf_cnt < app_buf_len; buf_cnt++ )
    {
        log_printf( &logger, "%c", app_buf[ buf_cnt ] );
    }
}

static err_t opto7_process ( opto7_t *ctx ) 
{
    uint8_t rx_buf[ PROCESS_BUFFER_SIZE ] = { 0 };
    int32_t overflow_bytes = 0;
    int32_t rx_cnt = 0;
    int32_t rx_size = opto7_generic_read( ctx, rx_buf, PROCESS_BUFFER_SIZE );
    if ( ( rx_size > 0 ) && ( rx_size <= APP_BUFFER_SIZE ) ) 
    {
        if ( ( app_buf_len + rx_size ) > APP_BUFFER_SIZE ) 
        {
            overflow_bytes = ( app_buf_len + rx_size ) - APP_BUFFER_SIZE;
            app_buf_len = APP_BUFFER_SIZE - rx_size;
            memmove ( app_buf, &app_buf[ overflow_bytes ], app_buf_len );
            memset ( &app_buf[ app_buf_len ], 0, overflow_bytes );
        }
        for ( rx_cnt = 0; rx_cnt < rx_size; rx_cnt++ ) 
        {
            if ( rx_buf[ rx_cnt ] ) 
            {
                app_buf[ app_buf_len++ ] = rx_buf[ rx_cnt ];
            }
        }
        return OPTO7_OK;
    }
    return OPTO7_ERROR;
}

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

Additional Support

Resources