Beginner
10 min

Manage various sensors and actuators with our I2C adapter and ATmega328

One Click to rule them all: Uniting devices on a single bus

8-pin I2C Click with Arduino UNO Rev3

Published Feb 14, 2024

Click board™

8-pin I2C Click

Dev Board

Arduino UNO Rev3

Compiler

NECTO Studio

MCU

ATmega328

This innovative product unlocks new possibilities in I2C connectivity, inspiring users to explore and unleash the full potential of 8-pin connections, fostering innovation and creativity in electronics projects.

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Hardware Overview

How does it work?

8-pin I2C Click is an adapter Click board™ that simplifies the connection of add-on boards to the mikroBUS™ socket. This Click board™ represents a small-size PCB that can be connected to the mikroBUS™ socket like any other Click board™, with a 2x4 female header placed on itself. Each header pin corresponds to a pin on the mikroBUS™ socket, such as I2C lines (SCL, SDA) with two jumpers for I2C lines pull-up function selection, 3V3 power supply, and ground. This Click board™ allows easy pin access and manipulation while always retaining a perfect connection

quality. Being compatible with Apple's MFI is the most important feature of the 8-pin I2C Click board™, which ensures its proper operation with additional Apple accessories. The name is a shortened version of the long-form Made for iPod, the original program that ultimately became MFI which refers to peripherals that work with Apple's iPod, iPad, and iPhone. 8-pin I2C Click communicates with MCU using the standard I2C 2-Wire interface. Lines of the mikroBUS™ to which this Click board™ is attached are shared through the top 8-pin female header, which mirrors

the pins of the connected mikroBUS™ socket. The 8-pin I2C Click also shares the 3V3 power rails, making it compatible with other power-compatible Click board™ and development systems. This Click board™ can only be operated with a 3.3V logic voltage level. The board must perform appropriate logic voltage level conversion before using MCUs with different logic levels. However, the Click board™ comes equipped with a library containing functions and an example code that can be used as a reference for further development.

8-pin-i2c-click-hardware-overview

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

32

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
NC
NC
5V
Ground
GND
GND
1

Take a closer look

Click board™ Schematic

8-pin I2C 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 via Debug Mode

1. Once the code example is loaded, pressing the "DEBUG" button initiates the build process, programs it on the created setup, and enters Debug mode.

2. After the programming is completed, a header with buttons for various actions within the IDE becomes visible. Clicking the green "PLAY" button starts reading the results achieved with the Click board™. The achieved results are displayed in the Application Output tab.

DEBUG_Application_Output

Software Support

Library Description

This library contains API for 8-pin I2C Click driver.

Key functions:

  • c8pini2c_generic_write - Generic write function.

  • c8pini2c_generic_read - Generic 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 8pinI2c Click example
 * 
 * # Description
 * This demo example reads temperature detected by Surface temp click board.
 *
 * The demo application is composed of two sections :
 * 
 * ## Application Init 
 * Initializes the driver and configures a Surface temp click board.
 * 
 * ## Application Task  
 * Reads the temperature detected by Surface temp click board and 
 * logs it on the USB UART each second.
 * 
 * @note
 * In order to run this example successfully, a Surface temp click board needs to be 
 * connected properly to an 8-pin I2C click board.
 * 
 * \author MikroE Team
 *
 */
// ------------------------------------------------------------------- INCLUDES

#include "board.h"
#include "log.h"
#include "c8pini2c.h"

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

static c8pini2c_t c8pini2c;
static log_t logger;

// Surface temp click - example
#define SURFACE_TEMP_DEVICE_SLAVE_ADDRESS 0x48
#define SURFACE_TEMP_REG_SOFT_RESET       0x2F
#define SURFACE_TEMP_REG_ID               0x0B
#define SURFACE_TEMP_REG_CONFIG           0x03
#define SURFACE_TEMP_REG_TEMP_MSB         0x00

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

void surfacetemp_soft_reset (  )
{
    uint8_t tx_data;

    tx_data = SURFACE_TEMP_REG_SOFT_RESET;

    c8pini2c_generic_write ( &c8pini2c, SURFACE_TEMP_DEVICE_SLAVE_ADDRESS, 
                                        0, &tx_data, 1 );
}

uint8_t surfacetemp_setup (  )
{
    uint8_t tmp;

    surfacetemp_soft_reset( );
    Delay_100ms( );
    c8pini2c_generic_read( &c8pini2c, SURFACE_TEMP_DEVICE_SLAVE_ADDRESS, 
                                      SURFACE_TEMP_REG_ID, &tmp, 1 );

    if ( tmp != 0xCB )
    {
        return 1;
    }
    tmp = 0x93;
    c8pini2c_generic_write( &c8pini2c, SURFACE_TEMP_DEVICE_SLAVE_ADDRESS, 
                                       SURFACE_TEMP_REG_CONFIG, &tmp, 1 );

    return 0;
}

float surfacetemp_get_temperature (  )
{
    uint8_t rx_buff[ 2 ];
    int16_t temp;
    float temperature;

    c8pini2c_generic_read( &c8pini2c, SURFACE_TEMP_DEVICE_SLAVE_ADDRESS, 
                                      SURFACE_TEMP_REG_TEMP_MSB, &rx_buff[ 0 ], 2 );

    temp = rx_buff[ 0 ];
    temp <<= 8;
    temp |= rx_buff[ 1 ];
    temp &= 0xFFF8;

    temperature = (float)(temp);
    temperature *= 0.0078;

    return temperature;
}

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

void application_init ( void )
{
    log_cfg_t log_cfg;
    c8pini2c_cfg_t cfg;

    uint8_t status;

    /** 
     * 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.

    c8pini2c_cfg_setup( &cfg );
    C8PINI2C_MAP_MIKROBUS( cfg, MIKROBUS_1 );
    c8pini2c_init( &c8pini2c, &cfg );

    status = surfacetemp_setup( );
    if ( status == 0 )
    {
        log_printf( &logger, "--- INIT DONE --- \r\n" );
    }
    else
    {
        log_printf( &logger, "--- INIT ERROR --- \r\n" );
        for( ; ; );
    }
}

void application_task ( void )
{
    float temperature;

    temperature = surfacetemp_get_temperature( );
    log_printf( &logger, "> Temperature : %.2f Celsius\r\n", temperature );
    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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