Achieve incredible success in analog multiplexing with CD74HC4067 and STM32F302VC

The ultimate analog switching solution

Analog MUX Click with CLICKER 4 for STM32F302VCT6

Published Jul 22, 2025

Click board™

Analog MUX Click

Dev. board

CLICKER 4 for STM32F302VCT6

Compiler

NECTO Studio

MCU

STM32F302VC

Achieve precise control over analog signals in complex systems with our 16-channel input switching solution optimized for high-performance applications in various industries

Hardware Overview

How does it work?

Analog MUX Click is based on the CD74HC4067, a high-speed CMOS logic 16-channel analog multiplexer/demultiplexer from Texas Instruments. It supports 3.3V and 5V power supplies, as well as rail-to-rail operation, allowing it to be used in various applications. Four control pins switch one of sixteen inputs to a single output. Control pins labeled as S0, S1, S2, and S3 are routed to the mikroBUS™ and can be operated by both 3.3V and 5V MCUs. These pins are routed to the RST, PWM, INT, and CS pins of the mikroBUS™, respectively, while the common output pin from the multiplexer is routed to the AN pin on the mikroBUS™. The CD74HC4067 IC is digitally controlled analog switch that utilize silicon-gate CMOS technology to achieve operating speeds similar to LSTTL, with the low power

consumption of standard CMOS integrated circuits. The mentioned analog multiplexer/demultiplexer control analog voltages that may vary across the voltage supply range. The ultra-low leakage current ensures that there is no signal interference from the inputs that are not selected by the S0, S1, S2, and S3 pins. A low crosstalk also ensures that the signal on one channel remains clean of interferences caused by other channels. To prevent any two inputs to be switched at the output at the same time, a break-before-make switching action is utilized. This ensures a reliable operation of the IC and the Click board™ itself. Analog MUX click is bidirectional switch as well, thus allowing any analog input to be used as an output and vice-versa. The switches have low “on” resistance and low “off” leakages.

All of the input channels can be easily connected to the two 9 pole spring action block terminals, without having to use any additional tools, such as screwdrivers. More information about the CD74HC4067 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.

Features overview

Development board

Clicker 4 for STM32F3 is a compact development board designed as a complete solution, you can use it to quickly build your own gadgets with unique functionalities. Featuring a STM32F302VCT6, four mikroBUS™ sockets for Click boards™ connectivity, power managment, and more, it represents a perfect solution for the rapid development of many different types of applications. At its core, there is a STM32F302VCT6 MCU, a powerful microcontroller by STMicroelectronics, based on the high-

performance Arm® Cortex®-M4 32-bit processor core operating at up to 168 MHz frequency. It provides sufficient processing power for the most demanding tasks, allowing Clicker 4 to adapt to any specific application requirements. Besides two 1x20 pin headers, four improved mikroBUS™ sockets represent the most distinctive connectivity feature, allowing access to a huge base of Click boards™, growing on a daily basis. Each section of Clicker 4 is clearly marked, offering an intuitive and clean interface. This makes working with the development

board much simpler and thus, faster. The usability of Clicker 4 doesn’t end with its ability to accelerate the prototyping and application development stages: it is designed as a complete solution which can be implemented directly into any project, with no additional hardware modifications required. Four mounting holes [4.2mm/0.165”] at all four corners allow simple installation by using mounting screws. For most applications, a nice stylish casing is all that is needed to turn the Clicker 4 development board into a fully functional, custom design.

CLICKER 4 for STM32F302VCT6 double image

Microcontroller Overview

MCU Card / MCU

Architecture

ARM Cortex-M4

MCU Memory (KB)

256

Silicon Vendor

STMicroelectronics

Pin count

100

RAM (Bytes)

40960

Used MCU Pins

mikroBUS™ mapper

Common Output

PC4

Control pin 0

PC15

RST

Control pin 3

PA4

SCK

MISO

MOSI

Power Supply

3.3V

Ground

GND

Control pin 1

PE9

PWM

Control pin 2

PD0

INT

SCL

SDA

Power Supply

Ground

GND

Take a closer look

Click board™ Schematic

Step by step

Project assembly

PIC32MZ MXS Data Capture Board front image hardware assembly

Start by selecting your development board and Click board™. Begin with the CLICKER 4 for STM32F302VCT6 as your development board.

Thermo 21 Click front image hardware assembly

Thermo 21 Click complete accessories setup image hardware assembly

Board mapper by product6 hardware assembly

PIC32MZ MXS Data Capture Board NECTO MCU Selection Step hardware assembly

Necto No Display image step 8 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 Analog MUX Click driver.

Key functions:

analogmux_get_voltage - Generic read voltage function
analogmux_set_channel - This function sets the active channel on the MUX.

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 
 * \brief AnalogMUX Click example
 * 
 * # Description
 * This example showcases how to initialize, configure and use the Analog MUX Click module. 
 * The Click switches one of the 16 inputs to output so the adc value of that input 
 * can be read on the COM (AN) pin. The RST, PWM, CS and INT are used as control output pins. 
 *
 * The demo application is composed of two sections :
 * 
 * ## Application Init 
 * This function initializes and configures the logger and Click modules.
 * 
 * ## Application Task  
 * This function reads ADC value and voltage from channel 0 (AN0) and shows the results 
 * on the USB UART every 2 seconds. 
 * 
 * \author MikroE Team
 *
 */
// ------------------------------------------------------------------- INCLUDES

#include "board.h"
#include "log.h"
#include "analogmux.h"

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

static analogmux_t analogmux;
static log_t logger;

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

void application_init ( void )
{
    log_cfg_t log_cfg;
    analogmux_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 );
    Delay_100ms( );
    log_info( &logger, "---- Application Init ----" );

    //  Click initialization.

    analogmux_cfg_setup( &cfg );
    ANALOGMUX_MAP_MIKROBUS( cfg, MIKROBUS_1 );
    analogmux_init( &analogmux, &cfg );

    analogmux_set_channel( &analogmux, ANALOGMUX_CHANNEL_0 );
    log_printf( &logger, " Channel 0 enabled\r\n" );
    log_printf( &logger, " -------------------\r\n" );
}

void application_task ( void )
{
    uint16_t tmp;
    float val;

    tmp = analogmux_generic_read( &analogmux );
    
    log_printf( &logger, " ADC value : %u\r\n", tmp );

    val = analogmux_generic_read_voltage( &analogmux );

    log_printf( &logger, " Voltage: %.3f mV\r\n", val );
    log_printf( &logger, " -------------------\r\n" );

    Delay_ms ( 1000 );
    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