Beginner
10 min

Detect the transition points in sinusoidal waveforms with PIC32MZ2048EFM100

Sense the ebb and flow of sinusoidal signals

Zero-Cross Click with Curiosity PIC32 MZ EF

Published Nov 12, 2023

Click board™

Zero-Cross Click

Dev Board

Curiosity PIC32 MZ EF

Compiler

NECTO Studio

MCU

PIC32MZ2048EFM100

Designed for engineers and innovators, our sinusoidal change detection solution ensures that you capture every shift in your signal, empowering you to respond effectively to dynamic changes in your applications.

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Hardware Overview

How does it work?

Zero-Cross Click is based on the circuitry that provides Zero Crossing Detection (ZCD). The alternate current can be connected over two block terminals. As it is intended for this Click board™ to work with high voltages, the critical components are placed on the bottom side, but still, take all precautions when working with this Click board™. On the top side is an AC ON LED to present the AC presence visually. All the magic is happening in

the circuitry at the bottom side of this Click board™. The current passes through the Graetz bridge circuitry, consisting of four DLGL5980. The alternate current converts to a direct current, which is necessary for driving an LED in an EL357N-G, a phototransistor photocoupler from Everlight. When activated, the optocoupler sends a LOW logic state to a ZC pin, the pin with which the Zero-Cross Click communicates with the

host MCU. 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.

Zero-Cross Click hardware overview image

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
Zero Crossing Detection
RF13
INT
NC
NC
TX
NC
NC
RX
NC
NC
SCL
NC
NC
SDA
Power Supply
5V
5V
Ground
GND
GND
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Take a closer look

Schematic

Zero-Cross 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
Curiosity PIC32 MZ EF MB 1 Access - upright/background 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

Track your results in real time

Application Output via Debug Mode

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

2. After the programming is completed, a header with buttons for various actions within the IDE becomes visible. Clicking the green "PLAY" button starts reading the results achieved with the Click board™. The achieved results are displayed in the Application Output tab.

DEBUG_Application_Output

Software Support

Library Description

This library contains API for Zero-Cross Click driver.

Key functions:

  • zerocross_pin_read - Zero-Cross pin reading function.

  • zerocross_get_freq - Zero-Cross frequency reading 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 Zero-Cross Click Example.
 *
 * # Description
 * This example demonstrates the use of the Zero-Cross Click board.
 *
 * The demo application is composed of two sections :
 *
 * ## Application Init
 * Initialization of the log UART and basic Click initialisation.
 *
 * ## Application Task
 * Reading frequency value approximately once every second.
 *
 * @author Stefan Ilic
 *
 */

#include "board.h"
#include "log.h"
#include "zerocross.h"

static zerocross_t zerocross;   /**< Zero-Cross Click driver object. */
static log_t logger;    /**< Logger object. */

void application_init ( void ) 
{
    log_cfg_t log_cfg;  /**< Logger config object. */
    zerocross_cfg_t zerocross_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.
    zerocross_cfg_setup( &zerocross_cfg );
    ZEROCROSS_MAP_MIKROBUS( zerocross_cfg, MIKROBUS_1 );
    if ( DIGITAL_OUT_UNSUPPORTED_PIN == zerocross_init( &zerocross, &zerocross_cfg ) ) 
    {
        log_error( &logger, " Communication init." );
        for ( ; ; );
    }
    
    log_info( &logger, " Application Task " );
}

void application_task ( void ) 
{
    float freq_val = 0;
    zerocross_get_freq( &zerocross, &freq_val );
    log_printf( &logger, " Freq %.2f Hz \n\r", freq_val );
}

void main ( void ) 
{
    application_init( );

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

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

Additional Support

Resources

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