Powering a sustainable future using BQ25570 and STM32F031K6
Efficient power, happy planet!
Published Oct 01, 2024
Click board™
Solar energy click
Dev. board
Nucleo 32 with STM32F031K6 MCU
Compiler
NECTO Studio
MCU
STM32F031K6
Provide power to your solution using the solar panel and charge the LiPo rechargeable battery efficiently
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Hardware Overview
How does it work?
Solar energy Click is based on the BQ25570, a nano-power high-efficiency boost charger, and buck converter from Texas Instruments, designed to work with very low-power energy harvesting elements. It can both provide power to the connected external load and charge the LiPo rechargeable battery using the solar panel as the photovoltaic element - employing its energy harvesting capabilities. The connected load will be powered on from the connected LiPo battery or the supercapacitor soldered on board. When the battery voltage drops under 2.85V, the interrupt pin (routed to the mikroBUS™ INT pin) will be driven to a LOW logic state. The integrated nano-power management unit provides the proper
charging conditions for the battery. When the battery is charged up to 3.25V due to the hysteresis set with the voltage divider resistors, the INT pin will again go to a HIGH logic state. Also, thanks to the nano-power management unit, the battery will not get overcharged above 4.06V. The click board™ provides 2.6V/100mA for the connected external load on the output terminal. The internal supercapacitor will be used as the energy storage element when the battery is not connected. This is useful for continuous powering up of very low-power applications, as the supercapacitor should be able to provide power continuously since it will get recharged by the solar panel before the load drains it out.
The internal converter will be disabled if the storage element voltage drops under the internally set under-voltage level of 1.95V, preventing the damage of completely draining out the connected storage element. In addition to the INT pin, there are two more pins of the BQ25570 routed to the mikroBUS™, used to enable the BQ25570 internal sections (EN) and to enable the power output for the connected load (OUT). Setting the EN pin to the LOW logic level will allow the BQ25570 internal sections and the power charger features, while the HIGH logic level on the OUT pin will enable the power output for the connected load.
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.
Microcontroller Overview
MCU Card / MCU
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.
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.
Solar Panel offers an efficient alternative powering solution for your device, harnessing the remarkable photoelectric effect to generate electricity when exposed to sunlight. Comprising monocrystalline silicon solar cells encapsulated with PC film lamination, this panel ensures durability and protection from environmental elements. The magic lies in the photoelectric effect, where sunlight excites electrons in the silicon cells, creating an electric current. The panel's construction optimizes sunlight absorption and conversion, enabling it to generate a minimum output of 4.0V. It can produce electrical power under a maximum load of 100mA, making it ideal for various applications. This solar panel offers a sustainable and eco-friendly approach, providing a renewable energy source that reduces reliance on conventional power grids and promotes environmental consciousness.
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 32 with STM32F031K6 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 Solar energy Click driver.
Key functions:
solarenergy_charge_enable- Charge enable functionsolarenergy_charge_disable- Charge disable functionssolarenergy_check_indicator- Battery good indicator functions
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 SOLAR ENERGY Click example
*
* # Description
* This application charge the batery when is empty.
*
* The demo application is composed of two sections :
*
* ## Application Init
* Initialization driver enables - GPIO and start to write log.
*
* ## Application Task
* This is an example which demonstrates the use of Solar Energy Click board.
* The following example will charge the battery if it is empty, and stop charging
* when the battery is full. When battery full status is detected, the device is
* disabled, but will check battery status every 10 seconds.
* Results are being sent to the Usart Terminal where you can track their changes.
*
* \author MikroE Team
*
*/
// ------------------------------------------------------------------- INCLUDES
#include "board.h"
#include "log.h"
#include "solarenergy.h"
// ------------------------------------------------------------------ VARIABLES
static solarenergy_t solarenergy;
static log_t logger;
void application_init ( void )
{
log_cfg_t log_cfg;
solarenergy_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.
solarenergy_cfg_setup( &cfg );
SOLARENERGY_MAP_MIKROBUS( cfg, MIKROBUS_1 );
solarenergy_init( &solarenergy, &cfg );
log_printf( &logger, " Initialization \r\n" );
log_printf( &logger, "--------------------\r\n" );
log_printf( &logger, " Charge the battery \r\n" );
log_printf( &logger, "--------------------\r\n" );
Delay_ms( 1000 );
}
void application_task ( void )
{
if ( solarenergy_check_indicator( &solarenergy ) )
{
solarenergy_charge_disable( &solarenergy );
Delay_ms ( 10000 );
}
else
{
solarenergy_charge_enable( &solarenergy );
}
}
void main ( void )
{
application_init( );
for ( ; ; )
{
application_task( );
}
}
// ------------------------------------------------------------------------ END
Additional Support
Resources
Category:Battery charger
