Beginner
10 min

Experience the freedom of choice in signal routing with TS3USB30E and ATmega324P

Simplify, switch, and surge ahead!

USB MUX Click with EasyAVR v7

Published Nov 12, 2023

Click board™

USB MUX Click

Dev Board

EasyAVR v7

Compiler

NECTO Studio

MCU

ATmega324P

Multiplexing differential outputs has never been easier – choose between two corresponding outputs from a USB host or effortlessly merge outputs from two different hosts for enhanced versatility.

A

A

Hardware Overview

How does it work?

USB MUX Click is based on the TS3USB30E, a USB 2.0 1:2 multiplexer/demultiplexer switch with a single enable from Texas Instruments. It is an ESD-protected device capable of bidirectional switching of high-speed USB 2.0 signals while offering little or no attenuation of the high-speed signals at the outputs. Besides the ESD protection, the TS3USB30E offers a low bit-to-bit skew and high channel-to-channel noise isolation. Also, besides USB 2.0, it is compatible with USB 1.1 standard. The maximum speed the TS3USB30E is

capable of is 480Mbps at USB 2.0. USB MUX Click communicates with the host MCU using a few GPIOs. The OE bus-switch enable pin allows users to isolate the bus when not in use and consume less current. With a LOW logic level set on the OE pin, you can use it in combination with the SEL pin to select one of two USB signal paths and connect it to a common USB signal path, with a LOW logic level to a USB1 and a HIGH logic level to a USB2. The USB1 is set by default over the pull-down resistors R5 and R6, which puts both OE and SEL

lines in a low logic state. In addition, the VBUS LED will indicate if the powered USB device is connected to the USB MUX Click. This Click board™ can only be operated with a 3.3V logic voltage level. The board must perform appropriate logic voltage level conversion before using MCUs with different logic levels. 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.

USB MUX Click hardware overview image

Features overview

Development board

EasyAVR v7 is the seventh generation of AVR development boards specially designed for the needs of rapid development of embedded applications. It supports a wide range of 16-bit AVR microcontrollers from Microchip and has a broad set of unique functions, such as a powerful onboard mikroProg programmer and In-Circuit debugger over USB. 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, EasyAVR v7 allows you to connect accessory boards, sensors, and custom electronics more

efficiently than ever. Each part of the EasyAVR 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 a wide range of external power sources, including an external 12V power supply, 7-12V AC or 9-15V 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 which cover a wide range of 16-bit AVR MCUs. EasyAVR 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.

EasyAVR v7 horizontal image

Microcontroller Overview

MCU Card / MCU

ATmega324P

Architecture

AVR

MCU Memory (KB)

32

Silicon Vendor

Microchip

Pin count

40

RAM (Bytes)

2048

Used MCU Pins

mikroBUS™ mapper

NC
NC
AN
Device Enable
PA6
RST
NC
NC
CS
NC
NC
SCK
NC
NC
MISO
NC
NC
MOSI
Power Supply
3.3V
3.3V
Ground
GND
GND
Input Selection
PD4
PWM
NC
NC
INT
NC
NC
TX
NC
NC
RX
NC
NC
SCL
NC
NC
SDA
NC
NC
5V
NC
NC
GND
1

Take a closer look

Schematic

USB MUX Click Schematic schematic

Step by step

Project assembly

EasyAVR v7 front image hardware assembly

Start by selecting your development board and Click board™. Begin with the EasyAVR v7 as your development board.

EasyAVR v7 front image hardware assembly
GNSS2 Click front image hardware assembly
MCU DIP 40 hardware assembly
GNSS2 Click complete accessories setup image hardware assembly
EasyAVR v7 Access DIP 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 DIP image step 7 hardware assembly
EasyPIC PRO v7a Display Selection Necto Step 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 via UART Mode

1. Once the code example is loaded, pressing the "FLASH" button initiates the build process, and programs it on the created setup.

2. After the programming is completed, click on the Tools icon in the upper-right panel, and select the UART Terminal.

3. After opening the UART Terminal tab, first check the baud rate setting in the Options menu (default is 115200). If this parameter is correct, activate the terminal by clicking the "CONNECT" button.

4. Now terminal status changes from Disconnected to Connected in green, and the data is displayed in the Received data field.

UART_Application_Output

Software Support

Library Description

This library contains API for USB MUX Click driver.

Key functions:

  • usbmux_set_oe_pin - USB MUX set OE pin output function.

  • usbmux_enable_output - USB MUX enable output function.

  • usbmux_set_output - USB MUX select output 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 main.c
 * @brief USB MUX Click Example.
 *
 * # Description
 * This example demonstrates the use of the USB MUX Click board.
 * This driver provides functions for device configurations 
 * and for the selection of the output.
 *
 * The demo application is composed of two sections :
 *
 * ## Application Init
 * Initialization of the log UART, performing default configuration which disables the output.
 *
 * ## Application Task
 * Reading user input from UART Terminal and using it for the selection of the output of 
 * disabling output of the USB MUX Click board.
 *
 * @author Stefan Ilic
 *
 */

#include "board.h"
#include "log.h"
#include "usbmux.h"

static usbmux_t usbmux;   /**< USB MUX Click driver object. */
static log_t logger;    /**< Logger object. */

/**
 * @brief Display possible selection function.
 * @details This function is used to display possible selections for the user input.
 * @return Nothing.
 * @note None.
 */
static void display_selection ( void );

void application_init ( void ) 
{
    log_cfg_t log_cfg;  /**< Logger config object. */
    usbmux_cfg_t usbmux_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.
    usbmux_cfg_setup( &usbmux_cfg );
    USBMUX_MAP_MIKROBUS( usbmux_cfg, MIKROBUS_1 );
    if ( DIGITAL_OUT_UNSUPPORTED_PIN == usbmux_init( &usbmux, &usbmux_cfg ) ) 
    {
        log_error( &logger, " Communication init." );
        for ( ; ; );
    }
    
    usbmux_default_cfg( &usbmux );
    
    log_info( &logger, " Application Task " );
    display_selection( );
}

void application_task ( void ) 
{
    static char index;
    
    if ( 1 == log_read( &logger, &index, 1 ) ) 
    {
        switch ( index )
        {
            case ( '0' ):
            {
                log_printf( &logger, " Turning output off. \r\n" );
                usbmux_disable_output( &usbmux );
                break;
            }
            case ( '1' ):
            {
                log_printf( &logger, " USB1 Enabled and selected. \r\n" );
                usbmux_set_output( &usbmux, USBMUX_USB1_SELECT );
                usbmux_enable_output( &usbmux );
                break;
            }
            case ( '2' ):
            {
                log_printf( &logger, " USB2 Enabled and selected. \r\n" );
                usbmux_set_output( &usbmux, USBMUX_USB2_SELECT );
                usbmux_enable_output( &usbmux );
                break;
            }
            default:
            {
                display_selection( );
            }
        }
    }
}

void main ( void ) 
{
    application_init( );

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

static void display_selection ( void )
{
    log_printf( &logger, "  To select USB output settings  \r\n" );
    log_printf( &logger, "  Send one of the numbers: \r\n" );
    log_printf( &logger, "- - - - - - - - - - - - - -\r\n" );
    log_printf( &logger, " '0' - Turn off output  \r\n" );
    log_printf( &logger, " '1' - Enable and select USB1 \r\n" );
    log_printf( &logger, " '2' - Enable and select USB2  \r\n" );
    log_printf( &logger, "---------------------------\r\n" );
}

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

Additional Support

Resources

Love this project?

'Buy This Kit' button takes you directly to the shopping cart where you can easily add or remove products.