Intermediate
30 min
0

Create an effective battery voltage balancer with MP2672A and TM4C1294NCZAD

Automatic cell imbalance correction

Balancer 4 Click with UNI Clicker

Published Mar 09, 2023

Click board™

Balancer 4 Click

Development board

UNI Clicker

Compiler

NECTO Studio

MCU

TM4C1294NCZAD

Maintain the charge balance between batteries

A

A

Hardware Overview

How does it work?

Balancer 4 Click is based on the MP2672A, a highly integrated and flexible switch-mode battery charger for two-cell Lithium-Ion batteries in series from Monolithic Power Systems (MPS). The MP2672A features a cell balance function that monitors the voltage across each cell and equalizes them if the difference exceeds the mismatch threshold. It features up to 2A of programmable charge current for batteries with two cells in series, alongside protections like battery temperature monitoring, programmable charging safety timer protection, JEITA-compliant battery NTC monitoring, cell over-voltage protection (OVP), thermal regulation, and thermal shutdown. The MP2672A has a narrow voltage DC (NVDC) power structure. It automatically detects the battery voltage and charges it in three phases: pre-charge, constant current, and voltage charge. With a deeply discharged battery, the MP2672A regulates the system output to a minimum voltage level, which powers the system

instantly while simultaneously charging the battery via integrated FET. It also offers flexible new charging cycle initiation compatible with Standalone mode and Host-control mode of operation selectable through an onboard switch labeled as HOST SEL. Diverse and robust protections include a thermal regulation loop to decrease the charge current if the junction temperature exceeds the thermal loop threshold and battery temperature protection compliant with JEITA standards. Other safety features include input over-voltage protection (OVP), battery OVP, thermal shutdown, battery temperature monitoring, and a configurable backup timer to prevent prolonged charging of a dead battery. Balancer 4 Click communicates with MCU using the standard I2C 2-Wire interface to read data and configure settings, supporting a Standard Mode operation up to 100kHz. It also has two LED indicators, red and green, marked with CHARGE and POWER, which can visually show

the existence of a good power supply to the MP2672A and the active status of the battery charging process. Also, an NTC function is available for temperature-qualified charging, where the MP2672A continuously monitors the battery’s temperature by measuring the voltage on the onboard NTC header pins. This Click board™ can operate with both 3.3V and 5V logic voltage levels selected via the VCC SEL jumper. It allows both 3.3V and 5V capable MCUs to use the communication lines properly. Additionally, there is a possibility for the MP2672A power supply selection via jumper labeled as VIN SEL to supply the MP2672A from an external power supply terminal in the range from 4V to 5.75V or with 5V voltage level from mikroBUS™ power rail. However, the 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.

balancer-4-click-hardware-overview

Features overview

Development board

UNI Clicker is a compact development board designed as a complete solution that brings the flexibility of add-on Click boards™ to your favorite microcontroller, making it a perfect starter kit for implementing your ideas. It supports a wide range of microcontrollers, such as different ARM, PIC32, dsPIC, PIC, and AVR from various vendors like Microchip, ST, NXP, and TI (regardless of their number of pins), four mikroBUS™ sockets for Click board™ connectivity, a USB connector, LED indicators, buttons, a debugger/programmer connector, and two 26-pin headers for interfacing with external electronics. Thanks to innovative manufacturing technology, it allows you to build

gadgets with unique functionalities and features quickly. Each part of the UNI Clicker development kit contains the components necessary for the most efficient operation of the same board. In addition to the possibility of choosing the UNI Clicker programming method, using a third-party programmer or CODEGRIP/mikroProg connected to onboard JTAG/SWD header, the UNI Clicker board also includes a clean and regulated power supply module for the development kit. It provides two ways of board-powering; through the USB Type-C (USB-C) connector, where onboard voltage regulators provide the appropriate voltage levels to each component on the board, or using a Li-Po/Li

Ion battery via an onboard battery connector. All communication methods that mikroBUS™ itself supports are on this board (plus USB HOST/DEVICE), including the well-established mikroBUS™ socket, a standardized socket for the MCU card (SiBRAIN standard), and several user-configurable buttons and LED indicators. UNI Clicker is an integral part of the Mikroe ecosystem, allowing you to create a new application in minutes. Natively supported by Mikroe software tools, it covers many aspects of prototyping thanks to a considerable number of different Click boards™ (over a thousand boards), the number of which is growing every day.

UNI clicker double image

Microcontroller Overview

MCU Card / MCU

default

Type

8th Generation

Architecture

ARM Cortex-M4

MCU Memory (KB)

1024

Silicon Vendor

Texas Instruments

Pin count

212

RAM (Bytes)

262144

You complete me!

Accessories

Li-Polymer Battery is the ideal solution for devices that demand a dependable and long-lasting power supply while emphasizing mobility. Its compatibility with mikromedia boards ensures easy integration without additional modifications. With a voltage output of 3.7V, the battery meets the standard requirements of many electronic devices. Additionally, boasting a capacity of 2000mAh, it can store a substantial amount of energy, providing sustained power for extended periods. This feature minimizes the need for frequent recharging or replacement. Overall, the Li-Polymer Battery is a reliable and autonomous power source, ideally suited for devices requiring a stable and enduring energy solution. You can find a more extensive choice of Li-Polymer batteries in our offer.

Balancer 4 Click accessories image

Used MCU Pins

mikroBUS™ mapper

NC
NC
AN
NC
NC
RST
NC
NC
CS
NC
NC
SCK
NC
NC
MISO
NC
NC
MOSI
Power Supply
3.3V
3.3V
Ground
GND
GND
NC
NC
PWM
NC
NC
INT
NC
NC
TX
NC
NC
RX
I2C Clock
PB2
SCL
I2C Data
PB3
SDA
Power Supply
5V
5V
Ground
GND
GND
1

Take a closer look

Schematic

Balancer 4 Click Schematic schematic

Step by step

Project assembly

UNI Clicker front image hardware assembly

Start by selecting your development board and Click board™. Begin with the UNI Clicker as your development board.

UNI Clicker front image hardware assembly
GNSS2 Click front image hardware assembly
SiBRAIN for STM32F745VG front image hardware assembly
Prog-cut hardware assembly
GNSS2 Click complete accessories setup image hardware assembly
UNI Clicker Access 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
Necto image step 7 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

After loading the code example, pressing the "DEBUG" button builds and programs it on the selected setup.

Application Output Step 1

After programming is completed, a header with buttons for various actions available in the IDE appears. By clicking the green "PLAY "button, we start reading the results achieved with Click board™.

Application Output Step 3

Upon completion of programming, the Application Output tab is automatically opened, where the achieved result can be read. In case of an inability to perform the Debug function, check if a proper connection between the MCU used by the setup and the CODEGRIP programmer has been established. A detailed explanation of the CODEGRIP-board connection can be found in the CODEGRIP User Manual. Please find it in the RESOURCES section.

Application Output Step 4

Software Support

Library Description

This library contains API for Balancer 4 Click driver.

Key functions:

  • balancer4_write_register This function writes a desired data byte to the selected register by using I2C serial interface.

  • balancer4_write_and_verify_register This function writes a desired data byte to the selected register and verifies if it is written correctly by reading it.

  • balancer4_read_register This function reads a data byte from the selected register by using I2C serial interface.

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 Balancer4 Click example
 *
 * # Description
 * This example demonstrates the use of Balancer 4 click board by configuring
 * the click board for charging and then reading the status and fault registers.
 *
 * The demo application is composed of two sections :
 *
 * ## Application Init
 * Initializes the driver and configures the click board for charging.
 *
 * ## Application Task
 * Reads and displays the status and fault registers on the USB UART every 500ms approximately.
 *
 * @author Stefan Filipovic
 *
 */

#include "board.h"
#include "log.h"
#include "balancer4.h"

static balancer4_t balancer4;
static log_t logger;

void application_init ( void ) 
{
    log_cfg_t log_cfg;  /**< Logger config object. */
    balancer4_cfg_t balancer4_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.
    balancer4_cfg_setup( &balancer4_cfg );
    BALANCER4_MAP_MIKROBUS( balancer4_cfg, MIKROBUS_1 );
    if ( I2C_MASTER_ERROR == balancer4_init( &balancer4, &balancer4_cfg ) ) 
    {
        log_error( &logger, " Communication init." );
        for ( ; ; );
    }
    
    if ( BALANCER4_ERROR == balancer4_default_cfg ( &balancer4 ) )
    {
        log_error( &logger, " Default configuration." );
        for ( ; ; );
    }
    
    log_info( &logger, " Application Task " );
}

void application_task ( void ) 
{
    uint8_t status, fault;
    if ( BALANCER4_OK == balancer4_read_register ( &balancer4, BALANCER4_REG_STATUS, &status ) )
    {
        log_printf ( &logger, "\r\n - STATUS - \r\n", status );
        log_printf ( &logger, " Battery status: " );
        if ( status & BALANCER4_STATUS_BATTERY_MISSING )
        {
            log_printf ( &logger, "missing\r\n" );
        }
        else
        {
            log_printf ( &logger, "present\r\n" );
            log_printf ( &logger, " Charging status: " );
            switch ( status & BALANCER4_STATUS_CHG_STAT_MASK )
            {
                case BALANCER4_STATUS_NOT_CHARGING:
                {
                    log_printf ( &logger, "not charging\r\n" );
                    break;
                }
                case BALANCER4_STATUS_PRE_CHARGE:
                {
                    log_printf ( &logger, "pre-charge\r\n" );
                    break;
                }
                case BALANCER4_STATUS_CONSTANT_CHARGE:
                {
                    log_printf ( &logger, "constant current or constant voltage charge\r\n" );
                    break;
                }
                case BALANCER4_STATUS_CHARGING_COMPLETE:
                {
                    log_printf ( &logger, "charging complete\r\n" );
                    break;
                }
            }
        }
    }
    if ( BALANCER4_OK == balancer4_read_register ( &balancer4, BALANCER4_REG_FAULT, &fault ) )
    {
        if ( fault )
        {
            log_printf ( &logger, "\r\n - FAULT - \r\n" );
            if ( fault & BALANCER4_FAULT_WD )
            {
                log_printf ( &logger, " The watchdog timer has expired\r\n" );
            }
            if ( fault & BALANCER4_FAULT_INPUT )
            {
                log_printf ( &logger, " Input OVP has occured\r\n" );
            }
            if ( fault & BALANCER4_FAULT_THERMAL_SD )
            {
                log_printf ( &logger, " Thermal shutdown\r\n" );
            }
            if ( fault & BALANCER4_FAULT_TIMER )
            {
                log_printf ( &logger, " The safety timer has expired\r\n" );
            }
            if ( fault & BALANCER4_FAULT_BAT )
            {
                log_printf ( &logger, " Battery OVP has occured\r\n" );
            }
            switch ( fault & BALANCER4_FAULT_NTC_MASK )
            {
                case BALANCER4_FAULT_NTC_COLD:
                {
                    log_printf ( &logger, " An NTC cold fault has occured\r\n" );
                    break;
                }
                case BALANCER4_FAULT_NTC_COOL:
                {
                    log_printf ( &logger, " An NTC cool fault has occured\r\n" );
                    break;
                }
                case BALANCER4_FAULT_NTC_WARM:
                {
                    log_printf ( &logger, " An NTC warm fault has occured\r\n" );
                    break;
                }
                case BALANCER4_FAULT_NTC_HOT:
                {
                    log_printf ( &logger, " An NTC hot fault has occured\r\n" );
                    break;
                }
            }
        }
    }
    Delay_ms ( 500 );
}

void main ( void ) 
{
    application_init( );

    for ( ; ; ) 
    {
        application_task( );
    }
}

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

Additional Support

Resources