Unlock the potential of your UART devices by effortlessly integrating them into I2C networks using our transformation solution, simplifying data exchange and enhancing control
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Hardware Overview
How does it work?
UART to I2C Click is based on the SC18IM704, a bridge between the standard UART port and a serial I2C bus from NXP Semiconductors. The SC18IM704 consists of a full-functional advanced UART interface that communicates with the host MCU through the commonly used RX and TX pins of the mikroBUS™ socket. It is also characterized by a high baud rate of up to 460.8 kbit/s and 256-byte FIFO for the transfer/receive data process. The serial data format is fixed to a one start bit, 8 data bits, and one stop bit. After the reset feature, the baud rate defaults to 9600 bit/s and can be changed through the Baud Rate Generator (BRG) registers. After a Power-Up sequence or already-mentioned hardware reset, achievable through the RST pin of the mikroBUS™ socket, the
SC18IM704 will send two continuous bytes to the host MCU to indicate a Start-Up condition. These two continuous bytes are 0x4F and 0x4B, representing an ‘OK’ state in the ASCII messages protocol. After the correct initial sequence, direct communication is enabled with other I2C-bus devices connected to the populated I2C-bus terminal. The I2C bus uses two wires (SCL and SDA) to transfer information between connected devices, providing a byte-oriented interface that supports data transfers up to 400kHz. The SC18IM704 can also be placed in a software-configurable low-power mode (Power-Down mode). Upon entering the Power-Down state, the UART RX pin is used to exit Deep Power-down mode. The bridge remains in the Deep
Power-down mode as long as the RX pin remains in a high logic state. Any character sent brings the bridge out of Deep Power-down mode but ignores the character. In addition to all these features, the SC18IM704 has several general-purpose I/O pins on the populated header with labeled GP pins. These pins have the option of software setting their function as push-pull, open-drain, or input-only. This Click board™ can be operated only with a 3.3V logic voltage level. The board must perform appropriate logic voltage level conversion before using MCUs with different logic levels. Also, it comes equipped with a library containing functions and an example code that can be used as a reference for further development.
Features overview
Development board
The 32L496GDISCOVERY Discovery kit serves as a comprehensive demonstration and development platform for the STM32L496AG microcontroller, featuring an Arm® Cortex®-M4 core. Designed for applications that demand a balance of high performance, advanced graphics, and ultra-low power consumption, this kit enables seamless prototyping for a wide range of embedded solutions. With its innovative energy-efficient
architecture, the STM32L496AG integrates extended RAM and the Chrom-ART Accelerator, enhancing graphics performance while maintaining low power consumption. This makes the kit particularly well-suited for applications involving audio processing, graphical user interfaces, and real-time data acquisition, where energy efficiency is a key requirement. For ease of development, the board includes an onboard ST-LINK/V2-1
debugger/programmer, providing a seamless out-of-the-box experience for loading, debugging, and testing applications without requiring additional hardware. The combination of low power features, enhanced memory capabilities, and built-in debugging tools makes the 32L496GDISCOVERY kit an ideal choice for prototyping advanced embedded systems with state-of-the-art energy efficiency.
Microcontroller Overview
MCU Card / MCU

Architecture
ARM Cortex-M4
MCU Memory (KB)
1024
Silicon Vendor
STMicroelectronics
Pin count
169
RAM (Bytes)
327680
Used MCU Pins
mikroBUS™ mapper
Take a closer look
Click board™ Schematic

Step by step
Project 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 UART to I2C Click driver.
Key functions:
uarttoi2c_gpio_write- This function writes a desired data to the gpio portuarttoi2c_gpio_read- This function reads data from the gpio portuarttoi2c_i2c_write_then_read- This function performs a write then read with a repeated start to the I2C target device.
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 UART to I2C Click Example.
*
* # Description
* This example demonstrates the use of USB to I2C Click board by reading the device ID
* of a 3D Hall 11 Click board connected to the I2C port and controlling the GPIO pins.
*
* The demo application is composed of two sections :
*
* ## Application Init
* Initializes the driver and performs the Click default config which resets
* the device and sets the GPIO pins 0-3 as push-pull output and others as input.
* After that, reads and displays the chip firmware version.
*
* ## Application Task
* Reads the device ID of a 3D Hall 11 Click board connected to the I2C port,
* toggles the output pins and displays the GPIO port state. The results will
* be displayed on the USB UART approximately once per second.
*
* @author Stefan Filipovic
*
*/
#include "board.h"
#include "log.h"
#include "uarttoi2c.h"
// I2C target device configuration
#define DEVICE_NAME "3D Hall 11 Click"
#define DEVICE_SLAVE_ADDRESS 0x35
#define DEVICE_REG_ID 0x0D
#define DEVICE_ID 0x01
static uarttoi2c_t uarttoi2c;
static log_t logger;
void application_init ( void )
{
log_cfg_t log_cfg; /**< Logger config object. */
uarttoi2c_cfg_t uarttoi2c_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.
uarttoi2c_cfg_setup( &uarttoi2c_cfg );
UARTTOI2C_MAP_MIKROBUS( uarttoi2c_cfg, MIKROBUS_1 );
if ( UART_ERROR == uarttoi2c_init( &uarttoi2c, &uarttoi2c_cfg ) )
{
log_error( &logger, " Communication init." );
for ( ; ; );
}
if ( UARTTOI2C_ERROR == uarttoi2c_default_cfg ( &uarttoi2c ) )
{
log_error( &logger, " Default configuration." );
for ( ; ; );
}
uint8_t version[ 16 ] = { 0 };
if ( UARTTOI2C_OK == uarttoi2c_read_version ( &uarttoi2c, version ) )
{
log_printf( &logger, " Firmware version: %s\r\n", version );
}
log_info( &logger, " Application Task " );
}
void application_task ( void )
{
static uint8_t gpio_state = UARTTOI2C_NO_PIN_MASK;
uint8_t slave_address = DEVICE_SLAVE_ADDRESS;
uint8_t reg_addr = DEVICE_REG_ID;
uint8_t device_id;
if ( UARTTOI2C_OK == uarttoi2c_i2c_write_then_read ( &uarttoi2c, slave_address,
®_addr, 1, &device_id, 1 ) )
{
log_printf( &logger, " %s - Device ID read: %s\r\n", ( char * ) DEVICE_NAME,
( char * ) ( ( DEVICE_ID == device_id ) ? "Success" : "Fail" ) );
}
uarttoi2c_gpio_write ( &uarttoi2c, gpio_state );
if ( UARTTOI2C_OK == uarttoi2c_gpio_read ( &uarttoi2c, &gpio_state ) )
{
log_printf( &logger, " GPIO state: 0x%.2X\r\n\n", ( uint16_t ) gpio_state );
gpio_state = ~gpio_state;
}
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
Category:I2C
































