Intermediate
30 min

Confidently separate and protect your I2C devices using ADUM2250 and ATmega328P

Protect and connect: Your trusted I2C isolation solution!

I2C Isolator 6 Click with Arduino UNO Rev3

Published Feb 14, 2024

Click board™

I2C Isolator 6 Click

Dev Board

Arduino UNO Rev3

Compiler

NECTO Studio

MCU

ATmega328P

Ensure the integrity of your I2C communication by isolating and safeguarding your signals from external influences

A

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Hardware Overview

How does it work?

I2C Isolator 6 Click is based on the ADUM2250, a two-channel, 5kVRMS I2C digital isolator from Analog Devices, suitable for hot-swap applications. The ADUM2250 bidirectionally buffers the two I2C signals across the isolation barrier while providing 5kVRMS of galvanic isolation. It transfers digital signals with data rates up to 1MHz between circuits with different power domains at ambient temperatures. It offers glitch-free operation,

excellent reliability, and a long operational life. The wide temperature range and high isolation voltage make the device ideal for harsh industrial environments. This Click board™ also possesses two terminals labeled as VIN and SDA/SCL at the top of the Click board™, where VIN represents the isolated-side power supply of the isolator, while the other corresponds to the isolated bidirectional logic-bus terminal. 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.

I2C Isolator 6 Click hardware overview image

Features overview

Development board

Arduino UNO is a versatile microcontroller board built around the ATmega328P chip. It offers extensive connectivity options for various projects, featuring 14 digital input/output pins, six of which are PWM-capable, along with six analog inputs. Its core components include a 16MHz ceramic resonator, a USB connection, a power jack, an

ICSP header, and a reset button, providing everything necessary to power and program the board. The Uno is ready to go, whether connected to a computer via USB or powered by an AC-to-DC adapter or battery. As the first USB Arduino board, it serves as the benchmark for the Arduino platform, with "Uno" symbolizing its status as the

first in a series. This name choice, meaning "one" in Italian, commemorates the launch of Arduino Software (IDE) 1.0. Initially introduced alongside version 1.0 of the Arduino Software (IDE), the Uno has since become the foundational model for subsequent Arduino releases, embodying the platform's evolution.

Arduino UNO Rev3 double side image

Microcontroller Overview

MCU Card / MCU

default

Architecture

AVR

MCU Memory (KB)

32

Silicon Vendor

Microchip

Pin count

28

RAM (Bytes)

2048

You complete me!

Accessories

Click Shield for Arduino UNO has two proprietary mikroBUS™ sockets, allowing all the Click board™ devices to be interfaced with the Arduino UNO board without effort. The Arduino Uno, a microcontroller board based on the ATmega328P, provides an affordable and flexible way for users to try out new concepts and build prototypes with the ATmega328P microcontroller from various combinations of performance, power consumption, and features. The Arduino Uno has 14 digital input/output pins (of which six can be used as PWM outputs), six analog inputs, a 16 MHz ceramic resonator (CSTCE16M0V53-R0), a USB connection, a power jack, an ICSP header, and reset button. Most of the ATmega328P microcontroller pins are brought to the IO pins on the left and right edge of the board, which are then connected to two existing mikroBUS™ sockets. This Click Shield also has several switches that perform functions such as selecting the logic levels of analog signals on mikroBUS™ sockets and selecting logic voltage levels of the mikroBUS™ sockets themselves. Besides, the user is offered the possibility of using any Click board™ with the help of existing bidirectional level-shifting voltage translators, regardless of whether the Click board™ operates at a 3.3V or 5V logic voltage level. Once you connect the Arduino UNO board with our Click Shield for Arduino UNO, you can access hundreds of Click boards™, working with 3.3V or 5V logic voltage levels.

Click Shield for Arduino UNO accessories 1 image

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
NC
NC
PWM
NC
NC
INT
NC
NC
TX
NC
NC
RX
I2C Clock
PC5
SCL
I2C Data
PC4
SDA
Power Supply
5V
5V
Ground
GND
GND
1

Take a closer look

Click board™ Schematic

I2C Isolator 6 Click Schematic schematic

Step by step

Project assembly

Click Shield for Arduino UNO front image hardware assembly

Start by selecting your development board and Click board™. Begin with the Arduino UNO Rev3 as your development board.

Click Shield for Arduino UNO front image hardware assembly
Arduino UNO Rev3 front image hardware assembly
Charger 27 Click front image hardware assembly
Prog-cut hardware assembly
Charger 27 Click complete accessories setup image hardware assembly
Arduino UNO Rev3 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 image step 5 hardware assembly
Necto image step 6 hardware assembly
Arduino UNO MCU Step hardware assembly
Necto No Display image step 8 hardware assembly
Necto image step 9 hardware assembly
Necto image step 10 hardware assembly
Debug Image Necto Step hardware assembly

Track your results in real time

Application Output

1. Application Output - In Debug mode, the 'Application Output' window enables real-time data monitoring, offering direct insight into execution results. Ensure proper data display by configuring the environment correctly using the provided tutorial.

2. UART Terminal - Use the UART Terminal to monitor data transmission via a USB to UART converter, allowing direct communication between the Click board™ and your development system. Configure the baud rate and other serial settings according to your project's requirements to ensure proper functionality. For step-by-step setup instructions, refer to the provided tutorial.

3. Plot Output - The Plot feature offers a powerful way to visualize real-time sensor data, enabling trend analysis, debugging, and comparison of multiple data points. To set it up correctly, follow the provided tutorial, which includes a step-by-step example of using the Plot feature to display Click board™ readings. To use the Plot feature in your code, use the function: plot(*insert_graph_name*, variable_name);. This is a general format, and it is up to the user to replace 'insert_graph_name' with the actual graph name and 'variable_name' with the parameter to be displayed.

Software Support

Library Description

This library contains API for I2C Isolator 6 Click driver.

Key functions:

  • i2cisolator6_write - I2C Isolator 6 I2C writing function

  • i2cisolator6_read - I2C Isolator 6 I2C reading function

  • i2cisolator6_write_then_read - I2C Isolator 6 I2C write then read function

Open Source

Code example

The complete application code and a ready-to-use project are available through the NECTO Studio Package Manager for direct installation in the NECTO Studio. The application code can also be found on the MIKROE GitHub account.

/*!
 * @file main.c
 * @brief I2C Isolator 6 Click example
 *
 * # Description
 * This library contains API for the I2C Isolator 6 Click driver.
 * This demo application shows an example of an I2C Isolator 6 Click 
 * wired to the Accel 21 Click for reading device ID.
 * The library also includes an I2C writing and reading functions.
 *
 * The demo application is composed of two sections :
 *
 * ## Application Init
 * The initialization of the I2C module, log UART.
 * After the driver init, the app sets Accel 21 Click I2C Slave address.
 *
 * ## Application Task
 * This example demonstrates the use of the I2C Isolator 6 Click board™.
 * Logs device ID values of the Accel 21 Click 
 * wired to the I2C Isolator 6 Click board™.
 *
 * @author Nenad Filipovic
 *
 */

#include "board.h"
#include "log.h"
#include "i2cisolator6.h"

#define ACCEL21_DEVICE_ADDRESS_GND    0x18
#define ACCEL21_DEVICE_ADDRESS_VCC    0x19
#define ACCEL21_REG_WHO_AM_I          0x0F
#define ACCEL21_DEVICE_ID             0x33

static i2cisolator6_t i2cisolator6;
static log_t logger;

void application_init ( void ) 
{
    log_cfg_t log_cfg;  /**< Logger config object. */
    i2cisolator6_cfg_t i2cisolator6_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.
    i2cisolator6_cfg_setup( &i2cisolator6_cfg );
    I2CISOLATOR6_MAP_MIKROBUS( i2cisolator6_cfg, MIKROBUS_1 );
    if ( I2C_MASTER_ERROR == i2cisolator6_init( &i2cisolator6, &i2cisolator6_cfg ) ) 
    {
        log_error( &logger, " Communication init." );
        for ( ; ; );
    }
    Delay_ms( 100 );
    
    if ( I2CISOLATOR6_ERROR == i2cisolator6_set_slave_address( &i2cisolator6, ACCEL21_DEVICE_ADDRESS_GND ) )
    {
        log_error( &logger, " Set I2C Slave address ERROR." );
        for ( ; ; );
    }
    Delay_ms( 100 );
    log_info( &logger, " Application Task " );
    log_printf( &logger, "---------------------\r\n" );
}

void application_task ( void ) 
{
    static uint8_t device_id = 0;
    static uint8_t reg = ACCEL21_REG_WHO_AM_I;
    if ( I2CISOLATOR6_OK == i2cisolator6_write_then_read( &i2cisolator6, &reg, 1, &device_id, 1 ) )
    {
        if ( ACCEL21_DEVICE_ID == device_id )
        {
            log_printf( &logger, " Device ID: 0x%.2X\r\n", ( uint16_t ) device_id );
            log_printf( &logger, "---------------------\r\n" );
        }
    }
    Delay_ms( 1000 );
}

void main ( void ) 
{
    application_init( );

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

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

Additional Support

Resources

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