Detect the transition points in sinusoidal waveforms with ATmega32
Sense the ebb and flow of sinusoidal signals
Published Nov 01, 2023
Click board™
Zero-Cross Click
Dev. board
EasyAVR v7
Compiler
NECTO Studio
MCU
ATmega32
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
EasyAVR v7 is the seventh generation of AVR development boards specially designed for the needs of rapid development of embedded applications. It supports a wide range of 16-bit AVR microcontrollers from Microchip and has a broad set of unique functions, such as a powerful onboard mikroProg programmer and In-Circuit debugger over USB. The development board is well organized and designed so that the end-user has all the necessary elements in one place, such as switches, buttons, indicators, connectors, and others. With four different connectors for each port, EasyAVR v7 allows you to connect accessory boards, sensors, and custom electronics more
efficiently than ever. Each part of the EasyAVR v7 development board contains the components necessary for the most efficient operation of the same board. An integrated mikroProg, a fast USB 2.0 programmer with mikroICD hardware In-Circuit Debugger, offers many valuable programming/debugging options and seamless integration with the Mikroe software environment. Besides it also includes a clean and regulated power supply block for the development board. It can use a wide range of external power sources, including an external 12V power supply, 7-12V AC or 9-15V DC via DC connector/screw terminals, and a power source via the USB Type-B (USB-B)
connector. Communication options such as USB-UART and RS-232 are also included, alongside the well-established mikroBUS™ standard, three display options (7-segment, graphical, and character-based LCD), and several different DIP sockets which cover a wide range of 16-bit AVR MCUs. EasyAVR v7 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
AVR
MCU Memory (KB)
32
Silicon Vendor
Microchip
Pin count
40
RAM (Bytes)
2048
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 EasyAVR v7 as your development board.
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 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 );
}
void main ( void )
{
application_init( );
for ( ; ; )
{
application_task( );
}
}
// ------------------------------------------------------------------------ END
