Integrate fiber-optic communication using IF-D91, IF-E97 and STM32F215RE for lightning-speed data exchange

Transforming designs with fiber-optic innovation

Published Aug 25, 2023

Click board™

Fiber Opt click

Dev Board

UNI-DS v8

Compiler

NECTO Studio

MCU

STM32F215RE

Integrate high-speed fiber-optic communication and establish reliable, secure networks to meet growing demands for rapid data exchange while enhancing overall performance and efficiency.

Hardware Overview

How does it work?

Fiber Opt Click is based on one IF-D91, a fiber-optic photodiode, and one IF-E97, a fiber-optic LED, both from Industrial Fiber Optics. The IF-D91 is a high-speed photodiode detector housed in a connector-less plastic fiber optic package. Its optical response extends from 400 to 1100nm, making it compatible with a wide range of visible and near-infrared LED and laser diode sources. The detector package features an internal micro-lens and a precision-molded PBT housing to ensure efficient optical coupling with standard 1000μm core 2.2mm jacketed plastic fiber cable capable of 100Mbps data rates. The IF-D91 can also be used for analog video links with bandwidths

up to 70MHz. The other precision-molded PBT housing with internal micro-lens, the IF-E97, is a high-optical-output visible red LED. The housing ensures efficient optical coupling with the same standard jacketed plastic fiber cable. The output spectrum is produced by a GaAlAs die, which peaks at 650nm, representing an optimal transmission window for PMMA plastic optical fiber. The visible red light has low attenuation in PMMA plastic fiber, aids troubleshooting installations, and is the main reason the IF-E97 achieves data rates of 1Mbps. This Click board™ communicates with the host MCU over selectable pins of the mikroBUS™ socket. Transmission can

be selected through the TX SEL selection jumper between the UART TX pin or PWM pin of the mikroBUS™ socket, as UART is selected by default. Received data is available on the RX pin of the mikroBUS™ socket. This Click board™ can operate with either 3.3V or 5V logic voltage levels selected via the PWR 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.

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.

Microcontroller Overview

MCU Card / MCU

Type

8th Generation

Architecture

ARM Cortex-M3

MCU Memory (KB)

512

Silicon Vendor

STMicroelectronics

Pin count

RAM (Bytes)

131072

Used MCU Pins

mikroBUS™ mapper

RST

SCK

MISO

MOSI

Power Supply

3.3V

Ground

GND

GPIO TX

PA1

PWM

INT

UART TX

PA2

UART RX

PA3

SCL

SDA

Power Supply

Ground

GND

Take a closer look

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.

NECTO Output Selection Step Image hardware assembly

In the advanced settings, pay special attention to the Redirect standard output field. By default, it is set to Application output as the method of displaying final results. To show results via a UART terminal, select the “UART” option in that field and click the “SAVE” button. You will be returned to the Compiler field, and now you can move on to the next step by pressing the “NEXT” button.

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 Compiler Selection Step 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.

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.

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".

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.

Software Support

Library Description

This library contains API for Fiber Opt Click driver.

Key functions:

fiberopt_generic_write - Generic single write function
fiberopt_generic_read - Generic single read 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 
 * \brief FiberOpt Click example
 * 
 * # Description
 * This application is an add-on for fiber-optical communication.
 *
 * The demo application is composed of two sections :
 * 
 * ## Application Init 
 * Initalizes UART driver and makes an initial log.
 * 
 * ## Application Task  
 * Example can either check if new data byte is received in rx buffer (ready for reading),
 * if ready than reads one byte from rx buffer and displays on USART terminal, or transmit message every 2 seconds.
 * 
 * \author MikroE Team
 *
 */
// ------------------------------------------------------------------- INCLUDES

#include "board.h"
#include "log.h"
#include "fiberopt.h"

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

#define DEMO_APP_RECEIVER
//#define DEMO_APP_TRANSMITER

static fiberopt_t fiberopt;
static log_t logger;

static char demo_message[ 9 ] = { 'M', 'i', 'k', 'r', 'o', 'E', 13, 10, 0 };

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

void application_init ( void )
{
    log_cfg_t log_cfg;
    fiberopt_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.

    fiberopt_cfg_setup( &cfg );
    FIBEROPT_MAP_MIKROBUS( cfg, MIKROBUS_1 );
    fiberopt_init( &fiberopt, &cfg );

    log_printf( &logger, "Initialized \r\n" );
    Delay_ms( 100 );
}

void application_task ( void )
{
    char tmp;
    
    //  Task implementation.
    
#ifdef DEMO_APP_RECEIVER

       // RECEIVER - UART polling

       tmp =  fiberopt_generic_single_read( &fiberopt );
       log_printf( &logger, "%c" , &tmp );
#endif
#ifdef DEMO_APP_TRANSMITER

       // TRANSMITER - TX each 2 sec
       
       fiberopt_generic_multi_write( &fiberopt, demo_message, 9 );
       Delay_ms( 2000 );
#endif
}

void main ( void )
{
    application_init( );

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


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