Identify and address power quality issues promptly with ACS37800 and PIC18LF26K42
Track and analyze power usage trends
Published Nov 01, 2023
Click board™
PWR Meter 3 Click - 90A
Dev Board
EasyPIC v8
Compiler
NECTO Studio
MCU
PIC18LF26K42
Our solution is designed to accurately measure voltage and current through your connected load, providing critical insights into electrical performance
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Hardware Overview
How does it work?
PWR Meter 3 Click is based on the ACS37800, a simple solution for voltage, current, and power monitoring from Allegro MicroSystems, which simplifies the addition of power monitoring in 60Hz to many AC/DC applications. The ACS37800 includes a copper conduction path that generates a magnetic field proportional to the applied current, sensed differentially to reject errors introduced by common mode fields. It is particularly well suited for high isolation, achieving reinforced isolation ratings of 4800 VRMS and a reliable ±90A bidirectional current sensing range. With high configurability and integrated features, this Click board™ can fit most power monitoring applications. The ACS37800 measures the voltage applied to the REF terminal, in the range from 9.5 to 27V, by resistor dividing it down to fit the input range of the onboard voltage sense amplifier and
add isolation. On the other hand, the current applied to the current sensing terminals is measured using the integrated current loop and galvanically isolated Hall sensor. Both analog signals are then sampled using integrated high-accuracy ADCs before entering the digital system. The metrology engine later determines the frequency, calculates RMS values of current, voltage, and power, and provides a range of averaging and configuration options. PWR Meter 3 Click communicates with an MCU using the standard I2C 2-Wire interface to read data and configure settings, supporting Standard Mode operation with a clock frequency of 100kHz and Fast Mode up to 400kHz. The ACS37800 can be turned on, or off through the EN pin routed to the RST pin of the mikroBUS™ socket, hence offering a switch operation to turn ON/OFF power delivery
to the ACS37800 via TPS2041B. Along with the ability to measure current and voltage, it also has two LED indicators, DIO0 and DIO1, for the realization of visual detection of some anomalies in operation, such as undervoltage and overvoltage reporting, and fast overcurrent fault detection. The DIO0 LED default state application is for zero crossing, while DIO1 stands for overcurrent detection. In addition to the LEDs, this information can be detected through the INT and AN pins of the mikroBUS™ socket, marked as D0 and D1. This Click board™ can be operated only with a 3.3V logic voltage level. The board must perform appropriate logic voltage level conversion before using MCUs with different logic levels. Also, it comes equipped with a library containing 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
28
RAM (Bytes)
4096
Used MCU Pins
mikroBUS™ mapper
Take a closer look
Schematic
Step by step
Project assembly
Start by selecting your development board and Click board™. Begin with the EasyPIC v8 as your development board.
Track your results in real time
Application Output
After pressing the "FLASH" button on the left-side panel, it is necessary to open the UART terminal to display the achieved results. By clicking on the Tools icon in the right-hand panel, multiple different functions are displayed, among which is the UART Terminal. Click on the offered "UART Terminal" icon.
Once the UART terminal is opened, the window takes on a new form. At the top of the tab are two buttons, one for adjusting the parameters of the UART terminal and the other for connecting the UART terminal. The tab's lower part is reserved for displaying the achieved results. Before connecting, the terminal has a Disconnected status, indicating that the terminal is not yet active. Before connecting, it is necessary to check the set parameters of the UART terminal. Click on the "OPTIONS" button.
In the newly opened UART Terminal Options field, we check if the terminal settings are correct, such as the set port and the Baud rate of UART communication. If the data is not displayed properly, it is possible that the Baud rate value is not set correctly and needs to be adjusted to 115200. If all the parameters are set correctly, click on "CONFIGURE".
The next step is to click on the "CONNECT" button, after which the terminal status changes from Disconnected to Connected in green, and the data is displayed in the Received data field.
Software Support
Library Description
This library contains API for PWR Meter 3 Click driver.
Key functions:
pwrmeter3_get_dio0_pin- This function returns the DIO0 pin logic statepwrmeter3_get_dio1_pin- This function returns the DIO1 pin logic statepwrmeter3_read_average_rms- This function reads the voltage and current RMS measurements averaged from a specified number of samples
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 PWR Meter 3 Click example
*
* # Description
* This example demonstrates the use of PWR Meter 3 click board by reading and displaying
* the voltage, current, and power RMS measurements.
*
* The demo application is composed of two sections :
*
* ## Application Init
* Initializes the driver and performs the click default configuration which sets the DC measurement
* and VRMS thresholds to about 28V for overvoltage and about 9.3V for undervoltage flag.
*
* ## Application Task
* Reads the voltage and current RMS values averaged from 500 samples, then calculates the power from it
* and displays the results on the USB UART. Also if an UV or OV flag is detected it will be logged accordingly.
*
* @author Stefan Filipovic
*
*/
#include "board.h"
#include "log.h"
#include "pwrmeter3.h"
static pwrmeter3_t pwrmeter3;
static log_t logger;
void application_init ( void )
{
log_cfg_t log_cfg; /**< Logger config object. */
pwrmeter3_cfg_t pwrmeter3_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.
pwrmeter3_cfg_setup( &pwrmeter3_cfg );
PWRMETER3_MAP_MIKROBUS( pwrmeter3_cfg, MIKROBUS_1 );
if ( I2C_MASTER_ERROR == pwrmeter3_init( &pwrmeter3, &pwrmeter3_cfg ) )
{
log_error( &logger, " Communication init." );
for ( ; ; );
}
if ( PWRMETER3_ERROR == pwrmeter3_default_cfg ( &pwrmeter3 ) )
{
log_error( &logger, " Default configuration." );
for ( ; ; );
}
log_info( &logger, " Application Task " );
}
void application_task ( void )
{
float v_rms, i_rms;
if ( PWRMETER3_OK == pwrmeter3_read_average_rms ( &pwrmeter3, &v_rms, &i_rms, PWRMETER3_DEF_AVG_SAMPLES ) )
{
if ( !pwrmeter3_get_dio0_pin ( &pwrmeter3 ) )
{
log_printf ( &logger, " Over-voltage detected!\r\n" );
}
if ( !pwrmeter3_get_dio1_pin ( &pwrmeter3 ) )
{
log_printf ( &logger, " Under-voltage detected!\r\n" );
}
log_printf ( &logger, " Voltage: %.2f V\r\n", v_rms );
log_printf ( &logger, " Current: %.2f A\r\n", i_rms );
log_printf ( &logger, " Power: %.2f W\r\n\n", i_rms * v_rms );
}
}
void main ( void )
{
application_init( );
for ( ; ; )
{
application_task( );
}
}
// ------------------------------------------------------------------------ END
