Experience the freedom to connect and control an array of I2C devices with PI4MSD5V9547 and TM4C129ENCPDT

Multiplexing marvel: I2C device management perfected!

Published Sep 04, 2023

Click board™

I2C MUX 7 Click

Dev. board

Fusion for Tiva v8

Compiler

NECTO Studio

MCU

TM4C129ENCPDT

Effortlessly manage your I2C device network with our multiplexer solution, making it an essential tool for engineers and developers seeking efficient and reliable communication in their projects

Hardware Overview

How does it work?

I2C MUX 7 Click is based on the PI4MSD5V9547, a low voltage octal bidirectional translating multiplexer with an active-low reset input controlled through the I2C serial interface from Texas Instruments. The host SCL/SDA signal pair is directed to eight channels CH0-CH7, where only one SCL/SDA channel can be selected at a time, determined by the contents of the programmable control register. The board powers up with Channel 0 connected, allowing immediate communication between the Host and downstream devices on that channel. This Click board™ includes a low dropout linear regulator AP2112 from Diodes Incorporated to provide the 1.8V supply voltage for the PI4MSD5V9547. When power is applied to the IC, an internal Power-On

Reset (POR) holds the PI4MSD5V9547 in a reset condition until the power supply reaches the POR voltage level. At this point, the reset condition is released, and the PI4MSD5V9547 registers and I2C-bus state machine are initialized to their default states (all zeroes), causing deselection of all channels. I2C MUX 7 Click communicates with MCU using the standard I2C 2-Wire interface that supports Standard-Mode (100 kHz) and Fast-Mode (400 kHz) operations. The PI4MSD5V9547 has a 7-bit slave address with the first five MSBs fixed to 1110. The address pins A0, A1, and A2 are programmed by the user and determine the value of the last three LSBs of the slave address, which can be selected by onboard SMD jumpers labeled as ADDR SEL, allowing selection of the slave

address LSBs. Alongside the internal Power-On Reset (POR) function, this board also has an active-low reset signal routed on the RST pin of the mikroBUS™ socket used to recover from a bus-fault condition. When this signal is asserted low, the PI4MSD5V9547 resets its registers alongside the I2C state machine and deselects all channels. 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. 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.

Features overview

Development board

Fusion for TIVA v8 is a development board specially designed for the needs of rapid development of embedded applications. It supports a wide range of microcontrollers, such as different 32-bit ARM® Cortex®-M based MCUs from Texas Instruments, regardless of their number of pins, and a broad set of unique functions, such as the first-ever embedded debugger/programmer over a WiFi network. The development board is well organized and designed so that the end-user has all the necessary elements, such as switches, buttons, indicators, connectors, and others, in one place. Thanks to innovative manufacturing technology, Fusion for TIVA v8 provides a fluid and immersive working experience, allowing access

anywhere and under any circumstances at any time. Each part of the Fusion for TIVA v8 development board contains the components necessary for the most efficient operation of the same board. An advanced integrated CODEGRIP programmer/debugger module offers many valuable programming/debugging options, including support for JTAG, SWD, and SWO Trace (Single Wire Output)), and seamless integration with the Mikroe software environment. Besides, it also includes a clean and regulated power supply module for the development board. It can use a wide range of external power sources, including a battery, an external 12V power supply, and a power source via the USB Type-C (USB-C) connector.

Communication options such as USB-UART, USB HOST/DEVICE, CAN (on the MCU card, if supported), and Ethernet is also included. In addition, it also has the well-established mikroBUS™ standard, a standardized socket for the MCU card (SiBRAIN standard), and two display options for the TFT board line of products and character-based LCD. Fusion for TIVA v8 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

Type

8th Generation

Architecture

ARM Cortex-M4

MCU Memory (KB)

1024

Silicon Vendor

Texas Instruments

Pin count

128

RAM (Bytes)

262144

Used MCU Pins

mikroBUS™ mapper

Reset

PK3

RST

SCK

MISO

MOSI

Power Supply

3.3V

Ground

GND

PWM

INT

I2C Clock

PD2

SCL

I2C Data

PD3

SDA

Power Supply

Ground

GND

Take a closer look

Click board™ Schematic

Step by step

Project assembly

Fusion for PIC v8 front image hardware assembly

Start by selecting your development board and Click board™. Begin with the Fusion for Tiva v8 as your development board.

NECTO Output Selection Step Image hardware assembly

In the advanced settings, pay special attention to the Redirect standard output field. By default, it is set to Application output as the method of displaying final results. To show results via a UART terminal, select the “UART” option in that field and click the “SAVE” button. You will be returned to the Compiler field, and now you can move on to the next step by pressing the “NEXT” button.

GNSS2 Click front image hardware assembly

SiBRAIN for PIC32MZ1024EFK144 front image hardware assembly

GNSS2 Click complete accessories setup image hardware assembly

v8 SiBRAIN Access MB 1 - upright/background hardware assembly

NECTO Compiler Selection Step Image 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 MUX 7 Click driver.

Key functions:

i2cmux7_set_channel - This function sets the desired channel active and configures its slave address
i2cmux7_read_channel - This function reads the currently selected channel value
i2cmux7_generic_read - This function reads a desired number of data bytes starting from the selected register by using I2C serial interface

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 I2CMUX7 Click example
 *
 * # Description
 * This example demonstrates the use of I2C MUX 7 click board by reading the
 * device ID of a 6DOF IMU 11 and Compass 3 click boards connected to 
 * the channels 0 and 7 respectfully.
 *
 * The demo application is composed of two sections :
 *
 * ## Application Init
 * Initializes the driver and resets the device.
 *
 * ## Application Task
 * Reads the device ID of the connected click boards.
 * Channel 0 : 6DOF IMU 11 click [slave address: 0x0E; reg: 0x00; id: 0x2D],
 * Channel 7 : Compass 3 click   [slave address: 0x30; reg: 0x2F; id: 0x0C].
 * All data is being logged on the USB UART where you can check the device ID.
 *
 * @author Stefan Filipovic
 *
 */

#include "board.h"
#include "log.h"
#include "i2cmux7.h"

#define DEVICE0_NAME                "6DOF IMU 11 click"
#define DEVICE0_POSITION            I2CMUX7_CHANNEL_0
#define DEVICE0_SLAVE_ADDRESS       0x0E
#define DEVICE0_REG_ID              0x00
#define DEVICE0_ID                  0x2D

#define DEVICE1_NAME                "Compass 3 click"
#define DEVICE1_POSITION            I2CMUX7_CHANNEL_7
#define DEVICE1_SLAVE_ADDRESS       0x30
#define DEVICE1_REG_ID              0x2F
#define DEVICE1_ID                  0x0C

static i2cmux7_t i2cmux7;
static log_t logger;

void application_init ( void ) 
{
    log_cfg_t log_cfg;  /**< Logger config object. */
    i2cmux7_cfg_t i2cmux7_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.
    i2cmux7_cfg_setup( &i2cmux7_cfg );
    I2CMUX7_MAP_MIKROBUS( i2cmux7_cfg, MIKROBUS_1 );
    if ( I2C_MASTER_ERROR == i2cmux7_init( &i2cmux7, &i2cmux7_cfg ) ) 
    {
        log_error( &logger, " Communication init." );
        for ( ; ; );
    }
    
    i2cmux7_reset_device ( &i2cmux7 );
    
    log_info( &logger, " Application Task " );
}

void application_task ( void ) 
{
    uint8_t channel, device_id;
    if ( I2CMUX7_OK == i2cmux7_set_channel ( &i2cmux7, DEVICE0_POSITION, DEVICE0_SLAVE_ADDRESS ) )
    {
        if ( I2CMUX7_OK == i2cmux7_read_channel ( &i2cmux7, &channel ) )
        {
            log_printf( &logger, " --- Channel %u --- \r\n", ( uint16_t ) ( channel & I2CMUX7_CHANNEL_NUM_MASK ) );
        }
        if ( I2CMUX7_OK == i2cmux7_generic_read ( &i2cmux7, DEVICE0_REG_ID, &device_id, 1 ) )
        {
            log_printf( &logger, " %s - Device ID: 0x%.2X \r\n\n", ( char * ) DEVICE0_NAME, ( uint16_t ) device_id );
        }
        Delay_ms( 1000 );
    }
    if ( I2CMUX7_OK == i2cmux7_set_channel ( &i2cmux7, DEVICE1_POSITION, DEVICE1_SLAVE_ADDRESS ) )
    {
        if ( I2CMUX7_OK == i2cmux7_read_channel ( &i2cmux7, &channel ) )
        {
            log_printf( &logger, " --- Channel %u --- \r\n", ( uint16_t ) ( channel & I2CMUX7_CHANNEL_NUM_MASK ) );
        }
        if ( I2CMUX7_OK == i2cmux7_generic_read ( &i2cmux7, DEVICE1_REG_ID, &device_id, 1 ) )
        {
            log_printf( &logger, " %s - Device ID: 0x%.2X \r\n\n", ( char * ) DEVICE1_NAME, ( uint16_t ) device_id );
        }
        Delay_ms( 1000 );
    }
}

void main ( void ) 
{
    application_init( );

    for ( ; ; ) 
    {
        application_task( );
    }
}

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