Intermediate
30 min
0

Unlock a new level of precision in UART signal routing with SN74LV4052A and TM4C1294KCPDT

Breaking the barriers of serial routing: Redefine your UART connectivity experience!

UART MUX Click with UNI-DS v8

Published Sep 21, 2023

Click board™

UART MUX Click

Development board

UNI-DS v8

Compiler

NECTO Studio

MCU

TM4C1294KCPDT

With our UART line-switching solution, you can confidently address applications such as multi-device communication, data logging, and UART interface management, where precise and flexible routing is essential

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Hardware Overview

How does it work?

UART MUX Click is based on the SN74LV4052A, a dual 4-channel multiplexer and demultiplexer from Texas Instruments. Two control pins are used to switch to one of four available outputs, from a single UART input, from the mikroBUS™. Control pins labeled as A and B, are routed to the mikroBUS™ and can be operated by both 3.3V and 5V MCUs. The fourth control pin is labeled as EN pin, and it is used to enable the internal multiplexing switches of the IC, when is set to a HIGH logic level (it is active HIGH). A and B pins are routed to CS and PWM pins of the mikroBUS™ respectively. The active low Inhibit (INH) tri-state all the channels when high and when low, depending on the A and B inputs, one of the four independent input/outputs is connected to the

UART communication pins. INH pin is routed to the RST pin on the mikroBUS™. The ultra-low leakage current ensures that there is no signal interference from the inputs that are not selected by the A and B pins. A low crosstalk also ensures that the signal on one channel remains clean of interferences caused by other channels. This ensures a reliable operation of the IC and the Click board™ itself. The output signals can be connected via the 2x4 pin headers. Besides RX and TX pins, every output also has dedicated VCC and GND pins avalilable, so that user can easily route multple devices with this Click board™. Independent power supply input allows the user to work with a wide range of signal amplitudes, depending on the application requirements, as

long as the power supply stays within the limits. More information about the SN74LV4052A can be found in the attached datasheet. However, the Click board™ comes equipped with a library that contains easy to use functions and a usage example that may be used as a reference for the development. 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.

UART MUX Click top side image
UART MUX Click bottom side image

Features overview

Development board

UNI-DS 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 STM32, Kinetis, TIVA, CEC, MSP, PIC, dsPIC, PIC32, and AVR MCUs regardless of their number of pins, and a broad set of unique functions, such as the first-ever embedded debugger/programmer over WiFi. 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, UNI-DS v8 provides a fluid and immersive working experience, allowing access anywhere and under any

circumstances at any time. Each part of the UNI-DS 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. UNI-DS 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.

UNI-DS v8 horizontal image

Microcontroller Overview

MCU Card / MCU

default

Type

8th Generation

Architecture

ARM Cortex-M4

MCU Memory (KB)

512

Silicon Vendor

Texas Instruments

Pin count

128

RAM (Bytes)

262144

Used MCU Pins

mikroBUS™ mapper

NC
NC
AN
Inhibit Input
PK3
RST
Control Pin A
PH0
CS
NC
NC
SCK
NC
NC
MISO
NC
NC
MOSI
Power Supply
3.3V
3.3V
Ground
GND
GND
Control Pin B
PL4
PWM
NC
NC
INT
UART TX
PK1
TX
UART RX
PK0
RX
NC
NC
SCL
NC
NC
SDA
Power Supply
5V
5V
Ground
GND
GND
1

Take a closer look

Schematic

UART MUX Click Schematic 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 UNI-DS v8 as your development board.

Fusion for PIC v8 front image hardware assembly
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 image step 2 hardware assembly
Necto image step 3 hardware assembly
Necto image step 4 hardware assembly
NECTO Compiler Selection Step Image hardware assembly
NECTO Output Selection Step Image hardware assembly
Necto image step 6 hardware assembly
Necto image step 7 hardware assembly
Necto image step 8 hardware assembly
Necto image step 9 hardware assembly
Necto image step 10 hardware assembly
Necto PreFlash Image hardware 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

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

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

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

Software Support

Library Description

This library contains API for UART MUX Click driver.

Key functions:

  • uartmux_send_command - Send command

  • uartmux_set_inhibit_communication - Set INT pin

  • uartmux_choose_channel - Choose channel

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 UartMux Click example
 * 
 * # Description
 * This example reads and processes data from UART Mux clicks.
 *
 * The demo application is composed of two sections :
 * 
 * ## Application Init 
 * Initializes driver.
 * 
 * ## Application Task  
 * Reads the received data.
 * 
 * ## Additional Function
 * - uartmux_process ( ) - The general process of collecting response
 *                                   from module.
 * 
 * \author MikroE Team
 *
 */
// ------------------------------------------------------------------- INCLUDES

#include "board.h"
#include "log.h"
#include "uartmux.h"
#include "string.h"

#define PROCESS_COUNTER 10
#define PROCESS_RX_BUFFER_SIZE 500

#define TEXT_TO_SEND  "MikroE\r\n"

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

#define DEMO_APP_RECEIVER
// #define DEMO_APP_TRANSMITER

static uartmux_t uartmux;
static log_t logger;

static uartmux_channel_t channel;

static int32_t rsp_size;
static char uart_rx_buffer[ PROCESS_RX_BUFFER_SIZE ] = { 0 };

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

static void uartmux_process ( void )
{
    rsp_size = uartmux_generic_read( &uartmux, &uart_rx_buffer, PROCESS_RX_BUFFER_SIZE, &channel );

    if ( rsp_size > 0 )
    {  
        for ( int32_t cnt = 0; cnt < rsp_size; cnt++ )
        {
            log_printf( &logger, "%c", uart_rx_buffer[ cnt ] );
        }
    }  
}

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

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

    /** 
     * 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.

    uartmux_cfg_setup( &cfg );
    UARTMUX_MAP_MIKROBUS( cfg, MIKROBUS_1 );
    uartmux_init( &uartmux, &cfg );

    uartmux_set_inhibit_communication( &uartmux, UARTMUX_PIN_STATE_LOW );
}

void application_task ( void )
{
#ifdef DEMO_APP_RECEIVER
    uartmux_process( );
#endif

#ifdef DEMO_APP_TRANSMITER
    channel.state_a = UARTMUX_STATE_A_CHANNEL_1;
    channel.state_b = UARTMUX_STATE_B_CHANNEL_1;

    uartmux_generic_write( &uartmux, TEXT_TO_SEND, strlen( TEXT_TO_SEND ), &channel );
    Delay_ms( 2000 );
#endif
}

void main ( void )
{
    application_init( );

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

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

Additional Support

Resources