Beginner
10 min

Protect your signals while maintaining uninterrupted communication using ADM3260 and ATmega328P

Power and data protection in one elegant package!

I2C Isolator 2 Click with Arduino UNO Rev3

Published Feb 14, 2024

Click board™

I2C Isolator 2 Click

Dev. board

Arduino UNO Rev3

Compiler

NECTO Studio

MCU

ATmega328P

Redefine your I2C isolation experience with our hot-swappable isolator, where power and data protection merge seamlessly, simplifying your setup and enhancing system reliability.

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Hardware Overview

How does it work?

I2C Isolator 2 Click is based on the ADM3260, a hot-swappable dual I2C isolator with an integrated DC-to-DC converter from Analog Devices. The digital isolator block is on each side of a bidirectional I2C signal. Internally, the I2C interface is split into two unidirectional channels communicating in opposing directions via a dedicated iCoupler isolation channel for each. One channel senses the voltage state of one side and transmits its state to its respective second side.

This isolator can achieve I2C clock speeds of up to 1MHz and supports 3 - 5.5V logic levels. I2C Isolator 2 Click uses a standard 2-Wire I2C interface to allow isolated communication between the host MCU and the connected I2C device. The isolator allows you to disable the I2C communication over the PDIS pin, which, with a High logic level, puts the isolator in standby mode. The I2C Isolator 2 Click is equipped with the VIO ISO jumper, which allows you to work with isolated different logic

levels. The 3V3 is set by default. This Click board™ can operate with either 3.3V or 5V logic voltage levels selected via the VIO 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 2 Click top side image
I2C Isolator 2 Click bottom side 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
Power Disable
PD6
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 2 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
Board mapper by product8 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 2 Click driver.

Key functions:

  • i2cisolator2_write - This function writes a desired data to I2C bus.

  • i2cisolator2_read - This function reads a desired number of data bytes from I2C bus.

  • i2cisolator2_set_slave_address - This function sets the slave address.

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 
 * \brief I2C Isolator 2 Click example
 * 
 * # Description
 * This example showcases how to initialize, configure and use the I2C Isolator 2 Click module.
 * The Click provides I2C lines and power isolation for slave devices. In order for this 
 * example to work, you need the EEPROM 3 Click.
 *
 * The demo application is composed of two sections :
 * 
 * ## Application Init 
 * Initializes the driver and enables the power output.
 * 
 * ## Application Task  
 * Writes the desired message to EEPROM 3 Click board and reads it back every 2 seconds.
 * All data is being displayed on the USB UART where you can track the program flow.
 * 
 * @note
 * Make sure to provide the VCC power supply on VCC pin and EEPROM 3 Click.
 * 
 * \author MikroE Team
 *
 */
// ------------------------------------------------------------------- INCLUDES

#include "board.h"
#include "log.h"
#include "i2cisolator2.h"

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

#define EEPROM3_MEMORY_ADDRESS   0x10000ul
#define EEPROM3_SLAVE_ADDRESS    0x54
#define EEPROM3_DEMO_TEXT        "MikroE - I2C Isolator 2 with EEPROM 3 Click!"

static i2cisolator2_t i2cisolator2;
static log_t logger;

// ------------------------------------------------------ ADDITIONAL FUNCTIONS

err_t eeprom3_write_page( uint32_t address, uint8_t *data_in, uint8_t len )
{
    uint8_t data_buf[ 257 ] = { 0 };
    uint8_t slave_addr = ( uint8_t ) ( ( address >> 16 ) & 0x03 ) | EEPROM3_SLAVE_ADDRESS;
    i2cisolator2_set_slave_address ( &i2cisolator2, slave_addr );
    data_buf[ 0 ] = ( uint8_t ) ( ( address >> 8 ) & 0xFF );
    data_buf[ 1 ] = ( uint8_t ) ( address & 0xFF );
    for ( uint8_t cnt = 0; cnt < len; cnt++ )
    {
        data_buf[ cnt + 2 ] = data_in[ cnt ];
    }
    return i2cisolator2_write( &i2cisolator2, data_buf, len + 2 );
}

err_t eeprom3_read_page( uint32_t address, uint8_t *data_out, uint8_t len )
{
    uint8_t data_buf[ 2 ] = { 0 };
    uint8_t slave_addr = ( uint8_t ) ( ( address >> 16 ) & 0x03 ) | EEPROM3_SLAVE_ADDRESS;
    i2cisolator2_set_slave_address ( &i2cisolator2, slave_addr );
    data_buf[ 0 ] = ( uint8_t ) ( ( address >> 8 ) & 0xFF );
    data_buf[ 1 ] = ( uint8_t ) ( address & 0xFF );
    err_t error_flag = i2cisolator2_write( &i2cisolator2, data_buf, 2 );
    error_flag |= i2cisolator2_read( &i2cisolator2, data_out, len );
    return error_flag;
}
// ------------------------------------------------------ APPLICATION FUNCTIONS

void application_init ( )
{
    log_cfg_t log_cfg;
    i2cisolator2_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.
    i2cisolator2_cfg_setup( &cfg );
    I2CISOLATOR2_MAP_MIKROBUS( cfg, MIKROBUS_1 );
    i2cisolator2_init( &i2cisolator2, &cfg );
    
    i2cisolator2_enable_power( &i2cisolator2, I2CISOLATOR2_POWER_ENABLE );
    Delay_ms ( 100 );

    log_info( &logger, " Application Task " );
}

void application_task ( )
{
    uint8_t read_buf[ 100 ] = { 0 };
    if ( I2CISOLATOR2_OK == eeprom3_write_page ( EEPROM3_MEMORY_ADDRESS, EEPROM3_DEMO_TEXT, 
                                                 strlen( EEPROM3_DEMO_TEXT ) ) )
    {
        log_printf( &logger, " Demo text message is written to EEPROM 3 Click!\r\n" );
    }
    Delay_ms ( 1000 );
    
    if ( I2CISOLATOR2_OK == eeprom3_read_page ( EEPROM3_MEMORY_ADDRESS, read_buf, 
                                                strlen( EEPROM3_DEMO_TEXT ) ) )
    {
        read_buf[ strlen( EEPROM3_DEMO_TEXT ) ] = 0;
        log_printf( &logger, " Read data: \"%s\"\r\n\n", read_buf );
    }
    Delay_ms ( 1000 );
}

int main ( void ) 
{
    /* Do not remove this line or clock might not be set correctly. */
    #ifdef PREINIT_SUPPORTED
    preinit();
    #endif
    
    application_init( );
    
    for ( ; ; ) 
    {
        application_task( );
    }

    return 0;
}

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

Additional Support

Resources

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