Beginner
10 min

Provide valuable information about the power consumption of your system with INA219 and STM32F031K6

12-bit power monitor for measuring power consumption

Power Monitor 2 Click with Nucleo 32 with STM32F031K6 MCU

Published Oct 01, 2024

Click board™

Power Monitor 2 Click

Dev. board

Nucleo 32 with STM32F031K6 MCU

Compiler

NECTO Studio

MCU

STM32F031K6

Provide valuable information for monitoring and managing power in embedded systems

A

A

Hardware Overview

How does it work?

Power Monitoring 2 Click is based on two INA219s, a 12-bit I2C-output digital power monitor from Texas Instruments for precise power monitoring. These ICs are specifically designed to monitor the power consumption of connected load devices by measuring the current and voltage on two separate power rails - 3.3V and 5V - of an additional mikroBUS™ socket. This configuration allows for monitoring these two power lines, ideal for evaluating the power usage of any Click board™ inserted into the onboard mikroBUS™ socket. Thanks to its flexibility, the INA219 allows power monitoring without any special power-supply sequencing, making it capable of monitoring power even when the supply or bus voltage is independently present or absent. The INA219s provide real-time digital readings of current, voltage, and power. It achieves this by sensing the voltage drop across shunt resistors (R3 and R4) connected to the bus of interest, and it can handle

bus voltages ranging from 0 to 26V. The device's programmable conversion times and filtering options ensure accurate measurements under various operating conditions. Additionally, the INA219 offers a programmable calibration value that, when combined with an internal multiplier, enables direct readouts of current in amperes and calculates power in watts through a multiplying register. As mentioned, the INA219 communicates with the host MCU using a standard 2-wire I2C interface, supporting High-Speed mode with clock frequencies up to 1MHz. Each INA219 IC on the Power Monitoring 2 Click has a configurable I2C address, which can be set using the ADDR SEL jumpers. These jumpers (U2 or U3, corresponding to each INA219) allow the selection of the desired I2C address by positioning them to either 0 or 1. Additionally, considering that this Click board™ can operate with both 3.3V and 5V logic levels, the voltage to which the pull-up resistors for the I2C

lines are connected can also be selected. This is achieved using the I2C PULL-UP jumpers, where the appropriate voltage level (3.3V or 5V) is selected by adjusting the jumpers accordingly. This board also features an onboard switch labeled CS SEL, which enables the CS line from the mikroBUS™ socket to communicate with the ClickID feature on the board. The CS line is redirected by setting the switch to the ON position, allowing the ClickID feature to function properly for identifying the connected Click board™. This Click board™ can operate with either 3.3V or 5V logic voltage levels. This way, both 3.3V and 5V capable MCUs can use the communication lines properly. As an added feature, it includes two green LED indicators that show which power rail is active, either 3.3V or 5V. 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 2 Click hardware overview image

Features overview

Development board

Nucleo 32 with STM32F031K6 MCU board provides an affordable and flexible platform for experimenting with STM32 microcontrollers in 32-pin packages. Featuring Arduino™ Nano connectivity, it allows easy expansion with specialized shields, while being mbed-enabled for seamless integration with online resources. The

board includes an on-board ST-LINK/V2-1 debugger/programmer, supporting USB reenumeration with three interfaces: Virtual Com port, mass storage, and debug port. It offers a flexible power supply through either USB VBUS or an external source. Additionally, it includes three LEDs (LD1 for USB communication, LD2 for power,

and LD3 as a user LED) and a reset push button. The STM32 Nucleo-32 board is supported by various Integrated Development Environments (IDEs) such as IAR™, Keil®, and GCC-based IDEs like AC6 SW4STM32, making it a versatile tool for developers.

Nucleo 32 with STM32F031K6 MCU double side image

Microcontroller Overview

MCU Card / MCU

default

Architecture

ARM Cortex-M0

MCU Memory (KB)

32

Silicon Vendor

STMicroelectronics

Pin count

32

RAM (Bytes)

4096

You complete me!

Accessories

Click Shield for Nucleo-32 is the perfect way to expand your development board's functionalities with STM32 Nucleo-32 pinout. The Click Shield for Nucleo-32 provides two mikroBUS™ sockets to add any functionality from our ever-growing range of Click boards™. We are fully stocked with everything, from sensors and WiFi transceivers to motor control and audio amplifiers. The Click Shield for Nucleo-32 is compatible with the STM32 Nucleo-32 board, providing an affordable and flexible way for users to try out new ideas and quickly create prototypes with any STM32 microcontrollers, choosing from the various combinations of performance, power consumption, and features. The STM32 Nucleo-32 boards do not require any separate probe as they integrate the ST-LINK/V2-1 debugger/programmer and come with the STM32 comprehensive software HAL library and various packaged software examples. This development platform provides users with an effortless and common way to combine the STM32 Nucleo-32 footprint compatible board with their favorite Click boards™ in their upcoming projects.

Click Shield for Nucleo-32 accessories 1 image

Used MCU Pins

mikroBUS™ mapper

Analog Output
PA0
AN
Reset
PA11
RST
SPI Select / ID COMM
PA4
CS
SPI Clock
PB3
SCK
SPI Data OUT
PB4
MISO
SPI Data IN
PB5
MOSI
Power Supply
3.3V
3.3V
Ground
GND
GND
PWM Signal
PA8
PWM
Interrupt
PA12
INT
UART TX
PA10
TX
UART RX
PA9
RX
I2C Clock
PB6
SCL
I2C Data
PB7
SDA
Power Supply
5V
5V
Ground
GND
GND
1

Take a closer look

Click board™ Schematic

Power Monitor 2 Click Schematic schematic

Step by step

Project assembly

Click Shield for Nucleo-144 front image hardware assembly

Start by selecting your development board and Click board™. Begin with the Nucleo 32 with STM32F031K6 MCU as your development board.

Click Shield for Nucleo-144 front image hardware assembly
Nucleo 144 with STM32L4A6ZG MCU front image hardware assembly
2x4 RGB Click front image hardware assembly
Prog-cut hardware assembly
Nucleo-32 with STM32 MCU MB 1 - 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
Clicker 4 for STM32F4 HA 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

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 Power Monitor 2 Click driver.

Key functions:

  • powermonitor2_set_address - This function sets the device slave address.

  • powermonitor2_read_data - This function reads the shunt voltage, bus voltage, current, and power data measurements.

  • powermonitor2_read_data_avg - This function reads the shunt voltage, bus voltage, current, and power data measurements averaged from num_conv samples.

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 Power Monitor 2 Click example
 *
 * # Description
 * This example demonstrates the use of Power Monitor 2 click by reading and displaying
 * the power consumption at 3V3 and 5V of the connected click board.
 *
 * The demo application is composed of two sections :
 *
 * ## Application Init
 * Initializes the driver and performs the click default configuration.
 *
 * ## Application Task
 * Reads the voltage, current, and power measurements from U2 and U3 sensors averaged
 * from 20 samples and displays the results on the USB UART.
 *
 * @author Stefan Filipovic
 *
 */

#include "board.h"
#include "log.h"
#include "powermonitor2.h"

static powermonitor2_t powermonitor2;
static log_t logger;

void application_init ( void ) 
{
    log_cfg_t log_cfg;  /**< Logger config object. */
    powermonitor2_cfg_t powermonitor2_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.
    powermonitor2_cfg_setup( &powermonitor2_cfg );
    POWERMONITOR2_MAP_MIKROBUS( powermonitor2_cfg, MIKROBUS_1 );
    if ( I2C_MASTER_ERROR == powermonitor2_init( &powermonitor2, &powermonitor2_cfg ) ) 
    {
        log_error( &logger, " Communication init." );
        for ( ; ; );
    }
    
    if ( POWERMONITOR2_ERROR == powermonitor2_default_cfg ( &powermonitor2 ) )
    {
        log_error( &logger, " Default configuration." );
        for ( ; ; );
    }
    
    log_info( &logger, " Application Task " );
}

void application_task ( void ) 
{
    powermonitor2_data_t pm_3v3, pm_5v;

    powermonitor2_set_address ( &powermonitor2, powermonitor2.address_3v3 );
    if ( POWERMONITOR2_OK == powermonitor2_read_data_avg ( &powermonitor2, POWERMONITOR2_DEFAULT_NUM_CONV, &pm_3v3 ) )
    {
        log_printf( &logger, " --- 3V3 Power Monitor ---\r\n" );
        log_printf( &logger, " Voltage: %.3f V\r\n", pm_3v3.bus_v );
        log_printf( &logger, " Current: %.3f A\r\n", pm_3v3.current );
        log_printf( &logger, " Power: %.2f W\r\n", pm_3v3.power );
        log_printf( &logger, " -------------------------\r\n" );
    }
    
    powermonitor2_set_address ( &powermonitor2, powermonitor2.address_5v );
    if ( POWERMONITOR2_OK == powermonitor2_read_data_avg ( &powermonitor2, POWERMONITOR2_DEFAULT_NUM_CONV, &pm_5v ) )
    {
        log_printf( &logger, " ---- 5V Power Monitor ---\r\n" );
        log_printf( &logger, " Voltage: %.3f V\r\n", pm_5v.bus_v );
        log_printf( &logger, " Current: %.3f A\r\n", pm_5v.current );
        log_printf( &logger, " Power: %.2f W\r\n", pm_5v.power );
        log_printf( &logger, " -------------------------\r\n" );
    }

    Delay_ms ( 1000 );
}

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

Additional Support

Resources

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