Take your engineering solution to the next level with isolated bidirectional I2C-compatible communication
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Hardware Overview
How does it work?
I2C Isolator Click is based on the ISO1540, a 2.5kVrms I2C digital isolator from Texas Instruments. The ISO1540 enables a completely isolated I2C interface, supporting Fast Mode Plus up to 1MHz, with two isolated bidirectional channels for clock and data lines. It provides advantages such as performance, size, and power consumption compared to optocouplers, which makes it suitable for multi-master and applications where slave clock stretching is possible. Isolated bidirectional communication is accomplished by offsetting the low-level output
voltage on the MCU side to a value greater than its high-level input voltage, preventing an internal logic latch that would occur with standard digital isolators. The ISO1540 has logic input and output buffers separated by Texas Instruments Capacitive Isolation technology using a silicon dioxide (SiO2) barrier. Also, the ISO1540 internally splits a bidirectional line into two unidirectional lines, each isolated through a single-channel digital isolator. This way, each channel output is made open-drain to comply with the open-drain technology of I2C. When used with isolated
power supplies, the ISO1540 blocks high voltages, isolates grounds, and prevents noise currents from entering the local ground and interfering with or damaging sensitive circuitry. This Click board™ can operate with either 3.3V or 5V logic voltage levels selected via the VCC1 SEL jumper. Therefore, both 3.3V and 5V capable MCUs to use the communication lines properly. The 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
EasyPIC v7 is the seventh generation of PIC development boards specially designed to develop embedded applications rapidly. It supports a wide range of 8-bit PIC microcontrollers from Microchip and has a broad set of unique functions, such as a powerful onboard mikroProg programmer and In-Circuit debugger over USB-B. The development board is well organized and designed so that the end-user has all the necessary elements in one place, such as switches, buttons, indicators, connectors, and others. With four different connectors for each port, EasyPIC v7 allows you to connect accessory boards, sensors, and custom electronics more efficiently than ever. Each part of
the EasyPIC v7 development board contains the components necessary for the most efficient operation of the same board. An integrated mikroProg, a fast USB 2.0 programmer with mikroICD hardware In-Circuit Debugger, offers many valuable programming/debugging options and seamless integration with the Mikroe software environment. Besides it also includes a clean and regulated power supply block for the development board. It can use various external power sources, including an external 12V power supply, 7-23V AC or 9-32V DC via DC connector/screw terminals, and a power source via the USB Type-B (USB-B) connector. Communication options such as
USB-UART and RS-232 are also included, alongside the well-established mikroBUS™ standard, three display options (7-segment, graphical, and character-based LCD), and several different DIP sockets. These sockets cover a wide range of 8-bit PIC MCUs, from PIC10F, PIC12F, PIC16F, PIC16Enh, PIC18F, PIC18FJ, and PIC18FK families. EasyPIC v7 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
![default](https://dbp-cdn.mikroe.com/catalog/mcus/resources/PIC18F26J11.jpeg)
Architecture
PIC
MCU Memory (KB)
64
Silicon Vendor
Microchip
Pin count
28
RAM (Bytes)
3800
Used MCU Pins
mikroBUS™ mapper
Take a closer look
Schematic
![I2C Isolator Click Schematic schematic](https://dbp-cdn.mikroe.com/catalog/click-boards/resources/1ee790ad-9416-67c8-a414-0242ac120009/schematic.webp)
Step by step
Project 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](https://dbp-cdn.mikroe.com/cms/shared-resources/1eed703a-40a0-6b58-88de-02420a00029a/UART-AO-Step-1.jpg)
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](https://dbp-cdn.mikroe.com/cms/shared-resources/1eed703a-eb29-62fa-ba91-02420a00029a/UART-AO-Step-2.jpg)
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](https://dbp-cdn.mikroe.com/cms/shared-resources/1eed703b-7543-6fbc-9c69-0242ac120003/UART-AO-Step-3.jpg)
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](https://dbp-cdn.mikroe.com/cms/shared-resources/1eed703c-068c-66a4-a4fc-0242ac120003/UART-AO-Step-4.jpg)
Software Support
Library Description
This library contains API for I2C Isolator Click driver.
Key functions:
i2cisolator_generic_write
- Generic write functioni2cisolator_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 I2Cisolator Click example
*
* # Description
* This is an example which demonstrates the use of I2C Isolator Click board.
*
* The demo application is composed of two sections :
*
* ## Application Init
* Initialization driver enables - I2C,
* sets configuration of TMP007 sensor on IrThermo 2 click and start to write log.
*
* ## Application Task
* In this example we use IrThermo 2 click, measures the temperature with,
* and calculate the temperature in degrees Celsius [ C ].
* Results are being sent to the USART Terminal where you can track their changes.
* All data logs on usb uart each second.
*
*
* \author MikroE Team
*
*/
// ------------------------------------------------------------------- INCLUDES
#include "board.h"
#include "log.h"
#include "i2cisolator.h"
/* Register Address */
#define I2CISOLATOR_IRTHERMO2_CONFIGURATION 0x02
#define I2CISOLATOR_IRTHERMO2_OBJECT_TEMPERATURE 0x03
#define I2CISOLATOR_IRTHERMO2_STATUS_MASK_AND_ENABLE 0x05
/* Commands */
#define I2CISOLATOR_IRTHERMO2_CFG_MODEON 0x1000
#define I2CISOLATOR_IRTHERMO2_CFG_ALERTEN 0x0100
#define I2CISOLATOR_IRTHERMO2_CFG_TRANSC 0x0040
#define I2CISOLATOR_IRTHERMO2_CFG_16SAMPLE 0x0800
#define I2CISOLATOR_IRTHERMO2_STAT_ALERTEN 0x8000
#define I2CISOLATOR_IRTHERMO2_STAT_CRTEN 0x4000
// ------------------------------------------------------------------ VARIABLES
static i2cisolator_t i2cisolator;
static log_t logger;
static float temperature;
// ------------------------------------------------------- ADDITIONAL FUNCTIONS
void i2cisolator_get_temperature ( void )
{
uint8_t temp_data[ 2 ];
uint16_t temp;
i2cisolator_generic_read( &i2cisolator, I2CISOLATOR_IRTHERMO2_OBJECT_TEMPERATURE, temp_data, 2 );
temp = temp_data[ 0 ];
temp <<= 8;
temp |= temp_data[ 1 ];
temp >>= 2;
temperature = ( float ) temp;
temperature *= 0.03125;
}
// ------------------------------------------------------ APPLICATION FUNCTIONS
void application_init ( void )
{
log_cfg_t log_cfg;
i2cisolator_cfg_t cfg;
uint8_t tmp;
/**
* 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.
i2cisolator_cfg_setup( &cfg );
I2CISOLATOR_MAP_MIKROBUS( cfg, MIKROBUS_1 );
i2cisolator_init( &i2cisolator, &cfg );
log_printf( &logger, " Driver Initialized\r\n" );
log_printf( &logger, "---------------------------\r\n" );
Delay_ms( 100 );
tmp = I2CISOLATOR_IRTHERMO2_CFG_MODEON |
I2CISOLATOR_IRTHERMO2_CFG_ALERTEN |
I2CISOLATOR_IRTHERMO2_CFG_TRANSC |
I2CISOLATOR_IRTHERMO2_CFG_16SAMPLE;
i2cisolator_generic_write( &i2cisolator, I2CISOLATOR_IRTHERMO2_CONFIGURATION, &tmp, 1 );
tmp = I2CISOLATOR_IRTHERMO2_STAT_ALERTEN |
I2CISOLATOR_IRTHERMO2_STAT_CRTEN;
i2cisolator_generic_write( &i2cisolator, I2CISOLATOR_IRTHERMO2_STATUS_MASK_AND_ENABLE, &tmp, 1 );
log_printf( &logger, " Configuration\r\n" );
log_printf( &logger, " IrThermo 2 Click\r\n" );
log_printf( &logger, "---------------------------\r\n" );
Delay_ms( 100 );
}
void application_task ( void )
{
i2cisolator_get_temperature( );
log_printf( &logger, " Temperature : %0.2f C\r\n", temperature );
log_printf( &logger, "---------------------------\r\n" );
Delay_ms( 1000 );
}
void main ( void )
{
application_init( );
for ( ; ; )
{
application_task( );
}
}
// ------------------------------------------------------------------------ END