Intermediate
30 min

Convert your signals simultaneously using PCF8591 and PIC32MZ2048EFM100

ADC/DAC combo

ADAC 3 Click with Curiosity PIC32 MZ EF

Published Jul 22, 2025

Click board™

ADAC 3 Click

Dev. board

Curiosity PIC32 MZ EF

Compiler

NECTO Studio

MCU

PIC32MZ2048EFM100

High-performance data acquisition solution

A

A

Hardware Overview

How does it work?

ADAC 3 Click is based on the PCF8591, a low-power CMOS data acquisition device from NXP Semiconductors. The PCF8591 comes with four analog inputs configurable as single-ended or differential inputs used to measure voltages, alongside one analog output representing an 8-bit digital-to-analog converter. In addition to measuring voltage, the user can create them as desired and even use DAC and ADC together to generate an input to a circuit and measure the results with the ADC, making it suitable for various control, monitoring, or measurement applications. By its internal structure, the PCF8591 also consists of

an analog input multiplexing circuit and an on-chip track and hold function alongside a serial interface block. This Click board™ communicates with MCU using the standard I2C 2-Wire interface with a maximum clock frequency of 100kHz. The PCF8591 has a 7-bit slave address with the first four MSBs fixed to 1001. 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 positioning onboard SMD jumpers labeled as ADDR SEL to an appropriate position marked as 0 or 1. Besides, the user can choose the PCF8591

reference voltage value by positioning the SMD jumper labeled VREF SEL, choosing between 2,048 and 4,096V provided by MAX6104 and MAX6106. 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.

adac-3-click-hardware-overview

Features overview

Development board

Curiosity PIC32 MZ EF development board is a fully integrated 32-bit development platform featuring the high-performance PIC32MZ EF Series (PIC32MZ2048EFM) that has a 2MB Flash, 512KB RAM, integrated FPU, Crypto accelerator, and excellent connectivity options. It includes an integrated programmer and debugger, requiring no additional hardware. Users can expand

functionality through MIKROE mikroBUS™ Click™ adapter boards, add Ethernet connectivity with the Microchip PHY daughter board, add WiFi connectivity capability using the Microchip expansions boards, and add audio input and output capability with Microchip audio daughter boards. These boards are fully integrated into PIC32’s powerful software framework, MPLAB Harmony,

which provides a flexible and modular interface to application development a rich set of inter-operable software stacks (TCP-IP, USB), and easy-to-use features. The Curiosity PIC32 MZ EF development board offers expansion capabilities making it an excellent choice for a rapid prototyping board in Connectivity, IOT, and general-purpose applications.

Curiosity PIC32MZ EF double side image

Microcontroller Overview

MCU Card / MCU

default

Architecture

PIC32

MCU Memory (KB)

2048

Silicon Vendor

Microchip

Pin count

100

RAM (Bytes)

524288

Used MCU Pins

mikroBUS™ mapper

NC
NC
AN
NC
NC
RST
NC
NC
CS
NC
NC
SCK
NC
NC
MISO
NC
NC
MOSI
Power Supply
3.3V
3.3V
Ground
GND
GND
NC
NC
PWM
NC
NC
INT
NC
NC
TX
NC
NC
RX
I2C Clock
RPA14
SCL
I2C Data
RPA15
SDA
Power Supply
5V
5V
Ground
GND
GND
1

Take a closer look

Click board™ Schematic

ADAC 3 Click Schematic schematic

Step by step

Project assembly

Curiosity PIC32MZ EF front image hardware assembly

Start by selecting your development board and Click board™. Begin with the Curiosity PIC32 MZ EF as your development board.

Curiosity PIC32MZ EF front image hardware assembly
GNSS2 Click front image hardware assembly
Prog-cut hardware assembly
GNSS2 Click complete accessories setup image hardware assembly
Board mapper by product7 hardware assembly
Necto image step 2 hardware assembly
Necto image step 3 hardware assembly
Necto image step 4 hardware assembly
Necto image step 5 hardware assembly
Necto image step 6 hardware assembly
Curiosity PIC32 MZ EF MCU Step hardware assembly
Necto No Display image step 8 hardware assembly
Necto image step 9 hardware assembly
Necto image step 10 hardware assembly
Debug Image Necto Step hardware assembly

Software Support

Library Description

This library contains API for ADAC 3 Click driver.

Key functions:

  • adac3_write_control This function writes a control byte by using I2C serial interface.

  • adac3_write_dac This function writes a DAC byte by using I2C serial interface.

  • adac3_read_adc This function reads the AD conversion byte 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 ADAC3 Click example
 *
 * # Description
 * This example demonstrates the use of ADAC 3 Click board by setting the DAC output
 * and reading the ADC results from 2 single-ended channels (AIN0, AIN1) and from a 
 * differential channel (AIN2+, AIN3-).
 *
 * The demo application is composed of two sections :
 *
 * ## Application Init
 * Initializes the driver and performs the Click default configuration which enables
 * DAC output, sets the analog input mode to single-ended (AIN0, AIN1) and 
 * differential (AIN2+, AIN3-), and enables the auto increment mode.
 *
 * ## Application Task
 * Sets the DAC output increasing the value by 1 after each iteration, and reads the 
 * ADC results from 2 single-ended and 1 differential channels, and displays the results
 * on the USB UART every 100ms approximately.
 *
 * @note
 * Inputs should be connected to GND when not in use.
 *
 * @author Stefan Filipovic
 *
 */

#include "board.h"
#include "log.h"
#include "adac3.h"

static adac3_t adac3;
static log_t logger;

void application_init ( void ) 
{
    log_cfg_t log_cfg;  /**< Logger config object. */
    adac3_cfg_t adac3_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.
    adac3_cfg_setup( &adac3_cfg );
    ADAC3_MAP_MIKROBUS( adac3_cfg, MIKROBUS_1 );
    if ( I2C_MASTER_ERROR == adac3_init( &adac3, &adac3_cfg ) ) 
    {
        log_error( &logger, " Communication init." );
        for ( ; ; );
    }
    
    if ( ADAC3_ERROR == adac3_default_cfg ( &adac3 ) )
    {
        log_error( &logger, " Default configuration." );
        for ( ; ; );
    }
    
    log_info( &logger, " Application Task " );
}

void application_task ( void ) 
{
    static uint8_t dac = 0;
    uint8_t ain0, ain1, ain2_ain3_diff;
    if ( ADAC3_OK == adac3_write_dac ( &adac3, dac ) )
    {
        log_printf ( &logger, " DAC : %u mV\r\n", 
                     ( uint16_t ) ( ( ADAC3_VREF_2048mV / ADAC3_RESOLUTION ) * dac++ ) );
    }
    if ( ADAC3_OK == adac3_read_adc ( &adac3, &ain0 ) )
    {
        log_printf ( &logger, " AIN0+: %u mV\r\n", 
                     ( uint16_t ) ( ( ADAC3_VREF_2048mV / ADAC3_RESOLUTION ) * ain0 ) );
    }
    if ( ADAC3_OK == adac3_read_adc ( &adac3, &ain1 ) )
    {
        log_printf ( &logger, " AIN1+: %u mV\r\n",
                     ( uint16_t ) ( ( ADAC3_VREF_2048mV / ADAC3_RESOLUTION ) * ain1 ) );
    }
    if ( ADAC3_OK == adac3_read_adc ( &adac3, &ain2_ain3_diff ) )
    {
        log_printf ( &logger, " AIN2+ - AIN3-: %d mV\r\n\n",
                     ( int16_t ) ( ( ADAC3_VREF_2048mV / ADAC3_RESOLUTION ) * ( int8_t ) ain2_ain3_diff ) );
    }
    Delay_ms ( 100 );
}

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

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.