Deliver swift and efficient power with BQ25792 and STM32G071RB
Fast, efficient, Li-Ion charging at your fingertips
Published Oct 08, 2024
Click board™
Charger 25 Click
Dev Board
Nucleo 64 with STM32G071RB MCU
Compiler
NECTO Studio
MCU
STM32G071RB
Elevate your charging experience with our Li-Ion battery charger, meticulously designed to deliver not just power, but optimized performance and prolonged device life.
A
A
Hardware Overview
How does it work?
Charger 25 Click is based on the BQ25792, a buck-boost battery charger with a dual-input selector and a USB PD3.0 OTG output from Texas Instruments. Additionally, the BQ25792 supports input source detection through D+ and D-, which is compatible with USB 2.0 and USB 3.0 power delivery, non-standard adapters, and high voltage adapters. With dual input source selection, USB OTG support, and an integrated 16-bit multi-channel analog-to-digital converter (ADC), the BQ25792 is a complete charging solution. The ADC monitors the charge current and input/battery/system voltages, the temperature qualification voltage input pin, and the die temperature, the data that can be used in BQ25792’s protection and interrupt systems. Charger 25 Click allows you to select the number of cells (cell count) to be charged and its optimal configuration over the 4-position CELL SEL jumper, where the 1s (1 cell) is set by default. With this feature, not only the cell count will be set, but also the switching frequency, where the values can be found in the table of the BQ25792’s datasheet, according to the used resistors on Charger 25 Click (for 1s, the switching frequency is 1.5MHz). This further sets the default charging current and voltage, which can be later altered depending on the selected cell count in a range from 3V up to 18.8V. The charging current also depends on the
cell count and can be either 1A or 2A. A BATT JST connector connects a battery (or batteries). Another cool feature of Charger 25 Click is the ability to use an external negative temperature coefficient thermistor (NTC) over the appropriate 2-pin header. The charge is suspended when the temperature is out of range. This feature can be enabled over the NTC SEL jumper where the NRM (normal) is set by default. A STAT LED indicator indicates charging in progress, charge complete, Hi-Z mode, charge suspend, and other statuses. The VBUS LED indicates the presence of the voltage on the VBUS rail, which includes both the USB C and a nearby VBUS header. Over the VBUS header, the charger can be supplied over a wide range of input voltages (3.6V – 24V). The charger employs a synchronous buck-boost converter that allows charging the 1s to 4s batteries from a legacy 5V USB input source, HVDCP, and USB-PD power sources. It operates uninterruptedly and continuously in buck, boost, or buck-boost mode, depending on the input-to-system output voltage difference. The converter operates in a proprietary buck-boost mode when the input voltage is close to the system output voltage. The charger output voltage to the system is available over the VSYS terminal. In the absence of the input sources, Charger 25 Click supports the USB
OtG function and can generate an adjustable 2.8V-22V voltage on the USB C connector (and VBUS terminal, too), which complies with the USB PD 3.0 specification. Fast Charging is also supported, as BQ25792 provides D+/D- handshake and is compliant with both USB 2.0 and USB 3.0 PD. Charger 25 Click uses a standard 2-Wire I2C interface to communicate with the host MCU, supporting a clock frequency of up to 1MHz. In addition to the I2C host-controlled charging mode, Charger 25 Click also supports autonomous charging mode. This way, after powering up, the charging is enabled with all default settings and can complete charging without software engagement. The QON pin can be used as a wake-up pin (ship FET enable) or for a system power reset control. The charger interrupts the host MCU over the INT pin, which can be statuses of even 18 events. The charge-enable CE pin can be used to turn off the charger. If connected to a LOW logic, the charger can complete charging autonomously. 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
Nucleo-64 with STM32G071RB MCU offers a cost-effective and adaptable platform for developers to explore new ideas and prototype their designs. This board harnesses the versatility of the STM32 microcontroller, enabling users to select the optimal balance of performance and power consumption for their projects. It accommodates the STM32 microcontroller in the LQFP64 package and includes essential components such as a user LED, which doubles as an ARDUINO® signal, alongside user and reset push-buttons, and a 32.768kHz crystal oscillator for precise timing operations. Designed with expansion and flexibility in mind, the Nucleo-64 board features an ARDUINO® Uno V3 expansion connector and ST morpho extension pin
headers, granting complete access to the STM32's I/Os for comprehensive project integration. Power supply options are adaptable, supporting ST-LINK USB VBUS or external power sources, ensuring adaptability in various development environments. The board also has an on-board ST-LINK debugger/programmer with USB re-enumeration capability, simplifying the programming and debugging process. Moreover, the board is designed to simplify advanced development with its external SMPS for efficient Vcore logic supply, support for USB Device full speed or USB SNK/UFP full speed, and built-in cryptographic features, enhancing both the power efficiency and security of projects. Additional connectivity is
provided through dedicated connectors for external SMPS experimentation, a USB connector for the ST-LINK, and a MIPI® debug connector, expanding the possibilities for hardware interfacing and experimentation. Developers will find extensive support through comprehensive free software libraries and examples, courtesy of the STM32Cube MCU Package. This, combined with compatibility with a wide array of Integrated Development Environments (IDEs), including IAR Embedded Workbench®, MDK-ARM, and STM32CubeIDE, ensures a smooth and efficient development experience, allowing users to fully leverage the capabilities of the Nucleo-64 board in their projects.
Microcontroller Overview
MCU Card / MCU
Architecture
ARM Cortex-M0
MCU Memory (KB)
128
Silicon Vendor
STMicroelectronics
Pin count
64
RAM (Bytes)
36864
You complete me!
Accessories
Click Shield for Nucleo-64 comes equipped with two proprietary mikroBUS™ sockets, allowing all the Click board™ devices to be interfaced with the STM32 Nucleo-64 board with no effort. This way, Mikroe allows its users to add any functionality from our ever-growing range of Click boards™, such as WiFi, GSM, GPS, Bluetooth, ZigBee, environmental sensors, LEDs, speech recognition, motor control, movement sensors, and many more. More than 1537 Click boards™, which can be stacked and integrated, are at your disposal. The STM32 Nucleo-64 boards are based on the microcontrollers in 64-pin packages, a 32-bit MCU with an ARM Cortex M4 processor operating at 84MHz, 512Kb Flash, and 96KB SRAM, divided into two regions where the top section represents the ST-Link/V2 debugger and programmer while the bottom section of the board is an actual development board. These boards are controlled and powered conveniently through a USB connection to program and efficiently debug the Nucleo-64 board out of the box, with an additional USB cable connected to the USB mini port on the board. Most of the STM32 microcontroller pins are brought to the IO pins on the left and right edge of the board, which are then connected to two existing mikroBUS™ sockets. This Click Shield also has several switches that perform functions such as selecting the logic levels of analog signals on mikroBUS™ sockets and selecting logic voltage levels of the mikroBUS™ sockets themselves. Besides, the user is offered the possibility of using any Click board™ with the help of existing bidirectional level-shifting voltage translators, regardless of whether the Click board™ operates at a 3.3V or 5V logic voltage level. Once you connect the STM32 Nucleo-64 board with our Click Shield for Nucleo-64, you can access hundreds of Click boards™, working with 3.3V or 5V logic voltage levels.
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.
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 Nucleo 64 with STM32G071RB MCU as your development board.
Track your results in real time
Application Output via Debug Mode
1. Once the code example is loaded, pressing the "DEBUG" button initiates the build process, programs it on the created setup, and enters Debug mode.
2. After the programming is completed, a header with buttons for various actions within the IDE becomes visible. Clicking the green "PLAY" button starts reading the results achieved with the Click board™. The achieved results are displayed in the Application Output tab.
Software Support
Library Description
This library contains API for Charger 25 Click driver.
Key functions:
charger25_get_vbat- Charger 25 get VBAT function.charger25_get_status- Charger 25 get charging status function.charger25_get_vbat_lim- Charger 25 get battery voltage limit 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 Charger 25 Click example
*
* # Description
* This example demonstrates the use of Charger 25 click board™
* by enabling battery charging and displaying battery voltage and charging status.
*
* The demo application is composed of two sections :
*
* ## Application Init
* Initialization of I2C module and log UART.
* After driver initialization, the app executes a default configuration.
*
* ## Application Task
* The demo application reads and displays the results of the battery voltage,
* minimal system voltage, battery voltage limit and charging status.
* Results are being sent to the UART Terminal, where you can track their changes.
*
* ## Additional Function
* - static void charger25_display_status ( void )
*
* @author Nenad Filipovic
*
*/
#include "board.h"
#include "log.h"
#include "charger25.h"
static charger25_t charger25;
static log_t logger;
static charger25_status_t status;
/**
* @brief Charger 25 displays the status.
* @details This function displays the charging status.
* @note None.
*/
static void charger25_display_status ( void );
void application_init ( void )
{
log_cfg_t log_cfg; /**< Logger config object. */
charger25_cfg_t charger25_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.
charger25_cfg_setup( &charger25_cfg );
CHARGER25_MAP_MIKROBUS( charger25_cfg, MIKROBUS_1 );
if ( I2C_MASTER_ERROR == charger25_init( &charger25, &charger25_cfg ) )
{
log_error( &logger, " Communication init." );
for ( ; ; );
}
if ( CHARGER25_ERROR == charger25_default_cfg ( &charger25 ) )
{
log_error( &logger, " Default configuration." );
for ( ; ; );
}
log_info( &logger, " Application Task " );
log_printf( &logger, " ----------------\r\n" );
Delay_ms( 100 );
}
void application_task ( void )
{
static uint16_t vtg_data = 0;
if ( CHARGER25_OK == charger25_get_status ( &charger25, &status ) )
{
charger25_display_status( );
}
Delay_ms( 100 );
if ( CHARGER25_OK == charger25_get_vbat( &charger25, &vtg_data ) )
{
log_printf( &logger, " VBAT: %u [mV]\r\n", vtg_data );
}
Delay_ms( 100 );
if ( CHARGER25_OK == charger25_get_vsys_min( &charger25, &vtg_data ) )
{
log_printf( &logger, " VMIN: %u [mV]\r\n", vtg_data );
}
Delay_ms( 100 );
if ( CHARGER25_OK == charger25_get_vbat_lim( &charger25, &vtg_data ) )
{
log_printf( &logger, " VLIM: %u [mV]\r\n", vtg_data );
}
log_printf( &logger, " ----------------\r\n" );
Delay_ms( 1000 );
}
void main ( void )
{
application_init( );
for ( ; ; )
{
application_task( );
}
}
static void charger25_display_status ( void )
{
log_printf( &logger, " Charge Status: " );
switch ( status.chg_stat )
{
case CHARGER25_CH_STAT_NOT_CHARGING:
{
log_printf( &logger, " Not Charging\r\n" );
break;
}
case CHARGER25_CH_STAT_TRICKLE_CHARGE:
{
log_printf( &logger, " Trickle Charge\r\n" );
break;
}
case CHARGER25_CH_STAT_PRE_CHARGE:
{
log_printf( &logger, " Pre-charge\r\n" );
break;
}
case CHARGER25_CH_STAT_FAST_CHARGE:
{
log_printf( &logger, " Fast charge \r\n" );
break;
}
case CHARGER25_CH_STAT_TAPER_CHARGE:
{
log_printf( &logger, " Taper Charge\r\n" );
break;
}
case CHARGER25_CH_STAT_TIMER_ACT_CHARGING:
{
log_printf( &logger, " Top-off Timer Active Charging\r\n" );
break;
}
case CHARGER25_CH_STAT_CHARGE_TERMIN_DONE:
{
log_printf( &logger, " Charge Termination Done\r\n" );
break;
}
default:
{
log_printf( &logger, " Unknown\r\n" );
break;
}
}
log_printf( &logger, " Battery Status: " );
if ( status.vbat_present_stat )
{
log_printf( &logger, " Battery present\r\n" );
}
else
{
log_printf( &logger, " No battery\r\n" );
}
log_printf( &logger, " - - - - - - - - \r\n" );
}
// ------------------------------------------------------------------------ END
