I2C Isolator 5 Click

How does it work?

I2C Isolator 5 Click is based on the ISO1644, a hot-swappable bidirectional I2C isolator with enhanced EMC and GPIOs from Texas Instruments. The ISO1644 bidirectionally buffers the two I2C signals across the isolation barrier while providing 5kVRMS of galvanic isolation. The isolation barrier consists of a double capacitive silicon dioxide and includes basic and reinforced insulation devices. In addition, the ISO1644 also integrates three unidirectional CMOS isolation channels with up to 50Mbps speed, which can be used for static GPIO signal isolation. It also integrates the logic required to support bidirectional channels.

ISO1644 supports I2C 2-Wire bidirectional data transfer between a host device and several peripheral devices, where the host MCU controls the bus, specifically the serial clock (SCL) line. The data transfer can be made in standard, fast, fast-mode plus, and high-speed mode with speeds up to 3.4Mbps. As for three GPIO lines, the ISO1644 consists of two lines in one direction and one in the opposite direction. It could be used for any GPIO purpose.

This Click board™ poses a terminal with isolated SCL and SDA lines. Besides, the terminal consists of VCC and GND lines and OUTA, OUTB, and INA, labeling the direction of the lines. Those GPIO lines are connected to the mikroBUS™ socket, thus the host MCU, via OTA, OTB, and INA pins. You can pull up the isolated I2C lines via unpopulated R6 and R7 jumpers if that suit your needs.

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. However, 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.

Specifications

Pinout diagram

This table shows how the pinout on I2C Isolator 5 Click corresponds to the pinout on the mikroBUS™ socket (the latter shown in the two middle columns).

Notes	Pin					Pin	Notes
	NC	1	AN	PWM	16	OTA	Output A Channel
Output B Channel	OTB	2	RST	INT	15	INT	Input A Channel
Chip Select	CS	3	CS	RX	14	NC
	NC	4	SCK	TX	13	NC
	NC	5	MISO	SCL	12	SCL	I2C Clock
	NC	6	MOSI	SDA	11	SDA	I2C Data
Power Supply	3.3V	7	3.3V	5V	10	5V	Power Supply
Ground	GND	8	GND	GND	9	GND	Ground

Onboard settings and indicators

I2C Isolator 5 Click electrical specifications

Software Support

We provide a library for the I2C Isolator 5 Click as well as a demo application (example), developed using MIKROE compilers. The demo can run on all the main MIKROE development boards.

Package can be downloaded/installed directly from NECTO Studio Package Manager (recommended), downloaded from our LibStock™ or found on Mikroe github account.

Library Description

This library contains API for I2C Isolator 5 Click driver.

Key functions

• i2cisolator5_set_slave_address I2C Isolator 5 set I2C Slave address function.

• i2cisolator5_set_outa_state I2C Isolator 5 set output A state function.

• i2cisolator5_get_ina_state I2C Isolator 5 get input A state function.

Example Description

This library contains API for the I2C Isolator 5 click driver. This demo application shows an example of an I2C Isolator 5 click
wired to the VAV Press click for reading
differential pressure and temperature measurement.

void application_task ( void ) 
{
    if ( I2CISOLATOR5_OK == i2cisolator5_get_press_and_temp( ) )
    {
        log_printf( &logger, " Diff. Pressure : %.4f Pa rn", diff_press );
        log_printf( &logger, " Temperature : %.2f C rn", temperature );
        log_printf( &logger, "--------------------------------rn" );
    }

    Delay_ms( 2000 );
}

The full application code, and ready to use projects can be installed directly from NECTO Studio Package Manager (recommended), downloaded from our LibStock™ or found on Mikroe github account.

Other Mikroe Libraries used in the example:

• MikroSDK.Board
• MikroSDK.Log
• Click.I2CIsolator5

Additional notes and informations

Depending on the development board you are using, you may need USB UART click, USB UART 2 Click or RS232 Click to connect to your PC, for development systems with no UART to USB interface available on the board. UART terminal is available in all MIKROE compilers.

mikroSDK

This Click board™ is supported with mikroSDK – MIKROE Software Development Kit, that needs to be downloaded from the LibStock and installed for the compiler you are using to ensure proper operation of mikroSDK compliant Click board™ demo applications.

For more information about mikroSDK, visit the official page.