Create general-purpose data selector with TMUX1308 and PIC32MZ1024EFH064

Analog multiplexer

Published Mar 06, 2023

Click board™

Analog MUX 4 Click

Dev. board

PIC32MZ clicker

Compiler

NECTO Studio

MCU

PIC32MZ1024EFH064

Choose one of many analog data inputs

Hardware Overview

How does it work?

Analog MUX 4 Click is based on the TMUX1308, a general-purpose 8:1 single-ended CMOS analog multiplexer from Texas Instruments. The TMUX1308 multiplexer allows for multiple inputs/sensors to be monitored with a single AN pin of the mikroBUS™ socket supporting bidirectional analog and digital signals ranging from 0 to 5V. It has an internal injection current control eliminating the need for external diode and resistor networks to protect the switch, keeping the input signals within the supply voltage. The internal injection current control circuitry allows signals on disabled signal paths to exceed the supply voltage without affecting the signal of the enabled signal path.

Alongside internal injection current control, the TMUX1308 also has another protection feature, called Break-before-make delay, which represents a safety feature preventing two inputs from connecting when the device is switching. The output first breaks from the ON-state switch before connecting with the next ON-state switch. This time delay between the break and the make is known as the break-before-make delay. This Click board™ communicates with MCU using several GPIO pins. It can be enabled or disabled through the EN pin of the mikroBUS™ socket, hence, offering a switch operation to turn ON/OFF power delivery to the TMUX1308. It also provides three address signals, labeled from A0 to A2, that control

the switch configuration and determine the activation of the desired analog input channel based on their setup. Also, each analog input has a jumper for its hardware activation or deactivation and capacitors for additional filtering of the input 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. However, the 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

PIC32MZ Clicker is a compact starter development board that brings the flexibility of add-on Click boards™ to your favorite microcontroller, making it a perfect starter kit for implementing your ideas. It comes with an onboard 32-bit PIC32MZ microcontroller with FPU from Microchip, a USB connector, LED indicators, buttons, a mikroProg connector, and a header for interfacing with external electronics. Thanks to its compact design with clear and easy-recognizable silkscreen markings, it provides a fluid and immersive working experience, allowing access anywhere and under

any circumstances. Each part of the PIC32MZ Clicker development kit contains the components necessary for the most efficient operation of the same board. In addition to the possibility of choosing the PIC32MZ Clicker programming method, using USB HID mikroBootloader, or through an external mikroProg connector for PIC, dsPIC, or PIC32 programmer, the Clicker board also includes a clean and regulated power supply module for the development kit. The USB Micro-B connection can provide up to 500mA of current, which is more than enough to operate all onboard

and additional modules. All communication methods that mikroBUS™ itself supports are on this board, including the well-established mikroBUS™ socket, reset button, and several buttons and LED indicators. PIC32MZ Clicker is an integral part of the Mikroe ecosystem, allowing you to create a new application in minutes. Natively supported by Mikroe software tools, it covers many aspects of prototyping 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

Architecture

PIC32

MCU Memory (KB)

1024

Silicon Vendor

Microchip

Pin count

RAM (Bytes)

524288

Used MCU Pins

mikroBUS™ mapper

Analog Signal

RE4

Switch Control 2

RE5

RST

Enable

RG9

SCK

MISO

MOSI

Power Supply

3.3V

Ground

GND

Switch Control 0

RB3

PWM

Switch Control 1

RB5

INT

SCL

SDA

Power Supply

Ground

GND

Take a closer look

Click board™ Schematic

Step by step

Project assembly

PIC32MZ clicker front image hardware assembly

Start by selecting your development board and Click board™. Begin with the PIC32MZ clicker as your development board.

GNSS2 Click front image hardware assembly

GNSS2 Click complete accessories setup image hardware assembly

Board mapper by product7 hardware assembly

Flip&Click PIC32MZ MCU step hardware assembly

Necto No Display image step 8 hardware assembly

Debug Image Necto Step hardware assembly

Software Support

Library Description

This library contains API for Analog MUX 4 Click driver.

Key functions:

analogmux4_enable_input This function enables analog inputs.
analogmux4_read_an_pin_voltage This function reads the results of the AD conversion of the AN pin and converts them to a proportional voltage level.
analogmux4_set_input_channel This function sets the analog input channel.

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 Analog MUX 4 Click Example.
 *
 * # Description
 * This example demonstrates the use of Analog MUX 4 Click board.
 *
 * The demo application is composed of two sections :
 *
 * ## Application Init
 * Initializes the driver and enables the analog inputs.
 *
 * ## Application Task
 * Reads and displays the voltage of all channels on the USB UART approximately once per second.
 *
 * @note
 * The channel's voltage will "float" when the voltage source is not connected to it.
 *
 * @author Stefan Filipovic
 *
 */

#include "board.h"
#include "log.h"
#include "analogmux4.h"

static analogmux4_t analogmux4;   /**< Analog MUX 4 Click driver object. */
static log_t logger;              /**< Logger object. */

void application_init ( void )
{
    log_cfg_t log_cfg;                /**< Logger config object. */
    analogmux4_cfg_t analogmux4_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.
    analogmux4_cfg_setup( &analogmux4_cfg );
    ANALOGMUX4_MAP_MIKROBUS( analogmux4_cfg, MIKROBUS_1 );
    if ( ADC_ERROR == analogmux4_init( &analogmux4, &analogmux4_cfg ) )
    {
        log_error( &logger, " Application Init Error. " );
        log_info( &logger, " Please, run program again... " );

        for ( ; ; );
    }
    
    analogmux4_enable_input ( &analogmux4 );
    log_info( &logger, " Application Task " );
}

void application_task ( void ) 
{
    float analogmux4_an_voltage = 0;
    
    for ( uint8_t cnt = ANALOGMUX4_CHANNEL_0; cnt <= ANALOGMUX4_CHANNEL_7; cnt++ )
    {
        analogmux4_set_input_channel ( &analogmux4, cnt );
        if ( ADC_ERROR != analogmux4_read_an_pin_voltage ( &analogmux4, &analogmux4_an_voltage ) ) 
        {
            log_printf( &logger, " AN%u voltage : %.3f V\r\n", ( uint16_t ) cnt, analogmux4_an_voltage );
        }
    }
    log_printf( &logger, "\r\n" );
    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