Achieve fast-charging of various rechargeable batteries with LT1571 and STM32L073RZ
Charge like a pro!
Published Feb 26, 2024
Click board™
Charger 16 Click
Dev. board
Nucleo-64 with STM32L073RZ MCU
Compiler
NECTO Studio
MCU
STM32L073RZ
Get the best of both worlds - add a high-performance battery charger to your solution that is both affordable and reliable
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Hardware Overview
How does it work?
Charger 16 Click is based on the LT1571, a current-mode PWM step-down (buck) charger from Analog Devices. This battery charger represents a simple, efficient solution to fast-charge rechargeable batteries, including lithium-ion (Li-Ion), nickel-metal-hydride (NiMH), and nickel-cadmium (NiCd) using constant-current or constant-voltage control. The internal switch can deliver a 1.5A DC (2A peak current). A saturating switch operates at 500kHz, which provides high efficiency and a small charger size. Charger 16 Click communicates with MCU using two GPIO pins. The Enable pin, labeled as EN and routed to the CS pin of the mikroBUS™ socket, optimizes power consumption and is used for power ON/OFF purposes (driver operation permission). The onboard current sense resistor (R7) allows simple charge current
programming with 5% accuracy. Charge current can be programmed with the PWM from the mikroBUS™ socket by pulse width modulating current on a PROG pin with a switch Q2 to R7 at a frequency higher than a few kHz. Charge current will be proportional to the duty cycle of Q2 with full current at 100% duty cycle. This Click board™ also comes with an indication, red LED labeled as CHARGE, for battery near full-charge state when the charge current drops to 20% of the programmed value, and selectable constant voltage for 4.1V or 4.2V per cell with 0.6% accuracy. Selection can be performed by onboard SMD jumper labeled as CELL SEL. Besides, the charge termination-flag threshold can be reduced from the default 20% level to as low as 7.5% of the programmed full charge current by positioning an onboard R5 resistor of appropriate value.
The Charger 16 Click supports an external power supply for the LT1571, which can be connected to the input terminal labeled as VIN and should be within the range of 8V to 20V. When the input voltage is removed, its supply voltage pin drops to 0.7V below the battery voltage forcing the charger into a low-battery drain (5mA typical) Sleep mode. This Click board™ can only be operated with a 5V logic voltage level. The board must perform appropriate logic voltage level conversion before using MCUs with different logic levels. However, the Click board™ 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 STM32L073RZ 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)
192
Silicon Vendor
STMicroelectronics
Pin count
64
RAM (Bytes)
20480
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
Click board™ Schematic
Step by step
Project assembly
Start by selecting your development board and Click board™. Begin with the Nucleo-64 with STM32L073RZ MCU as your development board.
Software Support
Library Description
This library contains API for Charger 16 Click driver.
Key functions:
charger16_cfg_setup- Config Object Initialization function.charger16_init- Initialization function.charger16_default_cfg- Click Default Configuration function.
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 Charger 16 Click Example.
*
* # Description
* This library contains API for the Charger 16 Click driver.
* This demo application shows use of a Charger 16 Click board™.
*
* The demo application is composed of two sections :
*
* ## Application Init
* Initialization of GPIO module and log UART.
* After driver initialization the app set default settings.
*
* ## Application Task
* This is an example that shows the use of an Charger 16 Click board™.
* The app turns the battery charge on and off every 10 seconds.
* Results are being sent to the Usart Terminal where you can track their changes.
*
* @author Nenad Filipovic
*
*/
#include "board.h"
#include "log.h"
#include "charger16.h"
static charger16_t charger16; /**< Charger 16 Click driver object. */
static log_t logger; /**< Logger object. */
void application_init ( void )
{
log_cfg_t log_cfg; /**< Logger config object. */
charger16_cfg_t charger16_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.
charger16_cfg_setup( &charger16_cfg );
CHARGER16_MAP_MIKROBUS( charger16_cfg, MIKROBUS_1 );
if ( charger16_init( &charger16, &charger16_cfg ) == DIGITAL_OUT_UNSUPPORTED_PIN )
{
log_error( &logger, " Application Init Error. " );
log_info( &logger, " Please, run program again... " );
for ( ; ; );
}
charger16_default_cfg ( &charger16 );
log_info( &logger, " Application Task " );
Delay_ms ( 100 );
}
void application_task ( void )
{
log_printf( &logger, "-----------------\r\n" );
log_printf( &logger, " Enable charging \r\n" );
charger16_enable_charging( &charger16 );
// 10 seconds delay
Delay_ms ( 1000 );
Delay_ms ( 1000 );
Delay_ms ( 1000 );
Delay_ms ( 1000 );
Delay_ms ( 1000 );
Delay_ms ( 1000 );
Delay_ms ( 1000 );
Delay_ms ( 1000 );
Delay_ms ( 1000 );
Delay_ms ( 1000 );
log_printf( &logger, "------------------\r\n" );
log_printf( &logger, " Disable charging \r\n" );
charger16_disable_charging( &charger16 );
// 10 seconds delay
Delay_ms ( 1000 );
Delay_ms ( 1000 );
Delay_ms ( 1000 );
Delay_ms ( 1000 );
Delay_ms ( 1000 );
Delay_ms ( 1000 );
Delay_ms ( 1000 );
Delay_ms ( 1000 );
Delay_ms ( 1000 );
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
Category:Battery charger
