30 min

Achieve the highest level of precision in power monitoring with INA228 and PIC18F45K40

Power insight redefined: Elevate performance with ultra-precise monitoring

Power Monitor Click with EasyPIC v8

Published Oct 09, 2023

Click board™

Power Monitor Click

Development board

EasyPIC v8


NECTO Studio



Our ultra-precise power monitoring solution redefines how you gain insight into your power usage, offering unmatched accuracy for optimizing performance, reducing costs, and ensuring the reliability of your systems



Hardware Overview

How does it work?

Power Monitor Click is based on the INA228, an ultra-precise digital power monitor with a 20-bit delta-sigma ADC and I2C digital interface from Texas Instruments. It measures shunt voltage, bus voltage, and internal temperature while calculating the current, power, energy, and charge necessary for accurate decisions in precisely controlled systems. It can measure a full-scale differential input of ±163.84mV or ±40.96mV across a resistive shunt sense element connected on the onboard IN terminal alongside common-mode voltage support up to +85V, which makes it well suited for both high-side and low-side current measurements. The INA228 also measures the bus supply voltage through the VBUS terminal and temperature through the integrated ±1°C accurate temperature sensor, which helps monitor the ambient system temperature. Power, charge, and energy calculations are performed in the

background and do not add to the overall ADC conversion time. Also, the very low offset voltage and noise allow for use in mA to kA sensing applications and provide a wide dynamic range without significant power dissipation losses on the sensing shunt element. Power Monitor Click communicates with MCU using the standard I2C 2-Wire interface to read data and configure settings, supporting a Fast Mode operation up to 400kHz. The INA228 also allows the selection of its I2C slave address using the two SMD cross-shape jumpers labeled A0 and A1. One cross-shape jumper has four positions for select address pins, which can be connected to GND, VS, SCL, or SDA pins. This way, the INA228 provides the opportunity of the 16 possible different I2C addresses by positioning the SMD jumper to an appropriate position. Besides, the INA228 also includes the multipurpose alert(interrupt) pin,

labeled as ALR and routed to the INT pin of the mikroBUS™ socket, used to report multiple diagnostics or as an indicator that the ADC conversion is complete when the device is operating in both triggered and continuous conversion mode. The diagnostics such as shunt over/under voltage limit, bus over/under voltage limit, or temperature or power over-limit are constantly monitored and reported through the ALR pin whenever the monitored output value crosses its associated out-of-range threshold. 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.

Power Monitor Click hardware overview image

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.

EasyPIC v8 horizontal image

Microcontroller Overview

MCU Card / MCU




MCU Memory (KB)


Silicon Vendor


Pin count


RAM (Bytes)


Used MCU Pins

mikroBUS™ mapper

Power Supply
Alert Interrupt
I2C Clock
I2C Data
Power Supply

Take a closer look


Power Monitor Click Schematic schematic

Step by step

Project assembly

EasyPIC v8 front image hardware assembly

Start by selecting your development board and Click board™. Begin with the EasyPIC v8 as your development board.

EasyPIC v8 front image hardware assembly
GNSS2 Click front image hardware assembly
MCU DIP 40 hardware assembly
GNSS2 Click complete accessories setup image hardware assembly
EasyPIC v8 Access DIPMB 1 - upright/background hardware assembly
Necto image step 2 hardware assembly
Necto image step 3 hardware assembly
Necto image step 4 hardware assembly
NECTO Compiler Selection Step Image hardware assembly
NECTO Output Selection Step Image hardware assembly
Necto image step 6 hardware assembly
Necto DIP image step 7 hardware assembly
Necto image step 8 hardware assembly
Necto image step 9 hardware assembly
Necto image step 10 hardware assembly
Necto PreFlash Image hardware assembly

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.

UART Application Output Step 1

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.

UART Application Output Step 2

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".

UART Application Output Step 3

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.

UART Application Output Step 4

Software Support

Library Description

This library contains API for Power Monitor Click driver.

Key functions:

  • powermonitor_get_vshunt - Power Monitor get shunt voltage function

  • powermonitor_get_vbus - Power Monitor get bus voltage function

  • powermonitor_get_current - Power Monitor get current 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 PowerMonitor Click example
 * # Description
 * This library contains API for Power Monitor Click driver.
 * The library initializes and defines the I2C bus drivers 
 * to write and read data from registers. 
 * The library also includes a function for reading 
 * Shunt and Bus voltage ( mV ), Current ( mA ), Power ( W ), Energy ( J ),   
 * as well as the Temperature in degrees Celsius.
 * The demo application is composed of two sections :
 * ## Application Init
 * The initialization of I2C  module, log UART, and additional pins. 
 * After the driver init and then executes a default configuration, 
 * the app checks communication, display Manufacturer, Stores Device and Revision ID. 
 * ## Application Task
 * This is an example that shows the use of a Power Monitor Click board™.
 * Measures and displays Shunt voltage ( mV ), Bus voltage ( mV ), 
 * Current ( mA ), Power ( W ), Energy ( J ) and Temperature ( degrees Celsius ). 
 * Results are being sent to the USART terminal where the user can track their changes. 
 * This task repeats every 2.5 sec.
 * @author Nenad Filipovic

#include "board.h"
#include "log.h"
#include "powermonitor.h"

static powermonitor_t powermonitor;
static log_t logger;

void application_init ( void ) 
    log_cfg_t log_cfg;                    /**< Logger config object. */
    powermonitor_cfg_t powermonitor_cfg;  /**< Click config object. */
    static uint8_t manufacturer_id[ 2 ];
    static uint16_t dieid;
    static uint8_t rev_id;
    powermonitor.shunt = 0.28;

     * 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.
    powermonitor_cfg_setup( &powermonitor_cfg );
    POWERMONITOR_MAP_MIKROBUS( powermonitor_cfg, MIKROBUS_1 );
    err_t init_flag = powermonitor_init( &powermonitor, &powermonitor_cfg );
    if ( I2C_MASTER_ERROR == init_flag ) 
        log_error( &logger, " Application Init Error. " );
        log_info( &logger, " Please, run program again... " );

        for ( ; ; );

    powermonitor_default_cfg ( &powermonitor );
    log_printf( &logger, "----------------------------\r\n" );
    Delay_ms( 100 );
    powermonitor_get_id( &powermonitor, &manufacturer_id, &dieid, &rev_id );
    log_printf( &logger, "  Manufacturer ID  : %.2s\r\n", manufacturer_id );
    log_printf( &logger, "  Stores Device ID : 0x%.3X\r\n", dieid );
    log_printf( &logger, "  Revision ID      : 0x%.1X\r\n", rev_id );
    log_printf( &logger, "----------------------------\r\n" );
    log_info( &logger, " Application Task " );
    log_printf( &logger, "----------------------------\r\n" );
    Delay_ms( 100 );

void application_task ( void ) 
    static float vshunt, vbus, current, power, energy, temperature;
    powermonitor_get_vshunt( &powermonitor, &vshunt );
    log_printf( &logger, " Shunt voltage : %.2f mV\r\n", vshunt );
    Delay_ms( 100 ); 
    powermonitor_get_vbus( &powermonitor, &vbus );
    log_printf( &logger, " BUS voltage   : %.2f mV\r\n", vbus );
    Delay_ms( 100 );
    powermonitor_get_current( &powermonitor, &current );
    log_printf( &logger, " Current       : %.2f mA\r\n", current );
    Delay_ms( 100 ); 
    powermonitor_get_power( &powermonitor, &power );
    log_printf( &logger, " Power         : %.6f W\r\n", power );
    Delay_ms( 100 ); 
    powermonitor_get_energy( &powermonitor, &energy );
    log_printf( &logger, " Energy        : %.6f J\r\n", energy );
    log_printf( &logger, "- - - - - - - - - - - - - - \r\n" );
    Delay_ms( 100 ); 
    powermonitor_get_temperature( &powermonitor, &temperature );
    log_printf( &logger, " Temperature   : %.2f C\r\n", temperature );
    log_printf( &logger, "----------------------------\r\n" );
    Delay_ms( 2000 );

void main ( void ) 
    application_init( );

    for ( ; ; ) 
        application_task( );

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

Additional Support