Detect the transition points in sinusoidal waveforms with PIC18F46K22
Sense the ebb and flow of sinusoidal signals
Published Nov 12, 2023
Click board™
Zero-Cross Click
Dev. board
EasyPIC v8
Compiler
NECTO Studio
MCU
PIC18F46K22
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.
Features overview
Development board
EasyPIC v8 is a development board specially designed for the needs of rapid development of embedded applications. It supports many high pin count 8-bit PIC microcontrollers from Microchip, regardless of their number of pins, and a broad set of unique functions, such as the first-ever embedded debugger/programmer. The development board is well organized and designed so that the end-user has all the necessary elements, such as switches, buttons, indicators, connectors, and others, in one place. Thanks to innovative manufacturing technology, EasyPIC v8 provides a fluid and immersive working experience, allowing access anywhere and under any
circumstances at any time. Each part of the EasyPIC v8 development board contains the components necessary for the most efficient operation of the same board. In addition to the advanced integrated CODEGRIP programmer/debugger module, which offers many valuable programming/debugging options and seamless integration with the Mikroe software environment, the board also includes a clean and regulated power supply module for the development board. It can use a wide range of external power sources, including a battery, an external 12V power supply, and a power source via the USB Type-C (USB-C) connector.
Communication options such as USB-UART, USB DEVICE, and CAN are also included, including the well-established mikroBUS™ standard, two display options (graphical and character-based LCD), and several different DIP sockets. These sockets cover a wide range of 8-bit PIC MCUs, from the smallest PIC MCU devices with only eight up to forty pins. EasyPIC v8 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.
Microcontroller Overview
MCU Card / MCU
Architecture
PIC
MCU Memory (KB)
64
Silicon Vendor
Microchip
Pin count
40
RAM (Bytes)
3896
Used MCU Pins
mikroBUS™ mapper
Take a closer look
Click board™ Schematic
Step by step
Project assembly
Start by selecting your development board and Click board™. Begin with the EasyPIC v8 as your development board.
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
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 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 );
}
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
