Improve your battery performance with MCP73871 and STM32F091RC
Charge smarter, charge faster
Published Feb 26, 2024
Click board™
MCP73871 click
Dev. board
Nucleo-64 with STM32F091RC MCU
Compiler
NECTO Studio
MCU
STM32F091RC
Upgrade your solution with state-of-the-art battery charger technology and ensure reliable charging performance every time
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Hardware Overview
How does it work?
MCP73871 Click is based on the MCP73871, a system load sharing and Li-Po/Li-Ion battery charge management integrated circuit from Microchip. This device completely manages the power distribution, utilizing many different steps. The input voltage is constantly monitored, and with no battery connected or with a battery element that is deeply depleted, the power to the connected load will be delivered straight from the external power supply provided by the 5V rail of the mikroBUS™ socket. The current that can be delivered in this mode depends on the limiting factor selected by the PRG2 pin. If the PRG2 pin is set to a LOW logic level, the current will be limited to 80mA - 100mA. If the PRG2 pin is set to a HIGH logic level, the current supplied to the load will be limited to 400mA - 500mA. Several conditions set by the MCP73871 device define the behavior of the power management logic. If a Li-Po/Li-Ion battery is connected to the battery connector, the charging procedure will go through the following steps.
The preconditioning mode is activated if the connected battery is deeply depleted and the CE (Charge Enable) pin is set to a HIGH logic level. The charging current is only a fraction of the regulated charging current used for fast charging, preventing battery damage and overheating. Suppose the battery voltage exceeds the preconditioning threshold voltage set by the MCP73871 device. In that case, the fast charging will begin, and the charging current is set by the PRG2 pin, as described above, and a voltage equal to 4.35V, as per factory settings of the MCP73871 IC. The charger circuit will stop the charging process when the complete charging conditions are met. The battery voltage is monitored, and another charging cycle will be repeated when it falls under the recharge threshold. During all the charging modes, the temperature of the MCP73871 die is monitored, so the charging current is regulated accordingly. The overtemperature protection will put the device in shutdown mode, preventing damage.
If the TE pin enables the Timer, it will limit the charging time if the battery voltage never reaches the end-of-charge condition. The MCP73871 power-sharing system logic enables simultaneously charging and powering up the system load, connected to the onboard output screw terminal. The power-sharing system is always active and prioritizes connected load over battery charging. Li-Po/Li-Ion battery can be connected to the onboard 2.54mm two-pin header. Three LEDs are used to indicate good power status, as well as the charging status. 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 STM32F091RC 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)
256
Silicon Vendor
STMicroelectronics
Pin count
64
RAM (Bytes)
32768
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 STM32F091RC MCU as your development board.
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 MCP73871 Click driver.
Key functions:
mcp73871_enable_pin_control- Enable pin controlmcp73871_prog_pin_control-Prog pin controlmcp73871_timer_pin_control- Timer pin control
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
* \brief MCP73871 Click example
*
* # Description
* This application is battery charger.
*
* The demo application is composed of two sections :
*
* ## Application Init
* Initializes the click driver, and enables the click board.
*
* ## Application Task
* This is the example of MCP73871 click functions usage.
* It enables this click, sets input current to 100mA,
* and enables safety timer.
*
* \author MikroE Team
*
*/
// ------------------------------------------------------------------- INCLUDES
#include "board.h"
#include "log.h"
#include "mcp73871.h"
// ------------------------------------------------------------------ VARIABLES
static mcp73871_t mcp73871;
static log_t logger;
// ------------------------------------------------------ APPLICATION FUNCTIONS
void application_init ( void )
{
log_cfg_t log_cfg;
mcp73871_cfg_t cfg;
/**
* 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.
mcp73871_cfg_setup( &cfg );
MCP73871_MAP_MIKROBUS( cfg, MIKROBUS_1 );
mcp73871_init( &mcp73871, &cfg );
}
void application_task ( void )
{
mcp73871_enable_pin_control( &mcp73871, 1 );
mcp73871_prog_pin_control( &mcp73871, 0 );
mcp73871_timer_pin_control( &mcp73871, 0 );
}
void main ( void )
{
application_init( );
for ( ; ; )
{
application_task( );
}
}
// ------------------------------------------------------------------------ END
