Intermediate
30 min

Powering a sustainable future using BQ25570 and PIC32MZ2048EFH100

Efficient power, happy planet!

Solar energy click with Flip&Click PIC32MZ

Published Jun 08, 2023

Click board™

Solar energy click

Dev. board

Flip&Click PIC32MZ

Compiler

NECTO Studio

MCU

PIC32MZ2048EFH100

Provide power to your solution using the solar panel and charge the LiPo rechargeable battery efficiently

A

A

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.

solar-energy-click-hardware-overview

Features overview

Development board

Flip&Click PIC32MZ 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 comes with an onboard 32-bit PIC32MZ microcontroller, the PIC32MZ2048EFH100 from Microchip, four mikroBUS™ sockets for Click board™ connectivity, two USB connectors, LED indicators, buttons, debugger/programmer connectors, and two headers compatible with Arduino-UNO pinout. Thanks to innovative manufacturing technology,

it allows you to build gadgets with unique functionalities and features quickly. Each part of the Flip&Click PIC32MZ development kit contains the components necessary for the most efficient operation of the same board. In addition, there is the possibility of choosing the Flip&Click PIC32MZ programming method, using the chipKIT bootloader (Arduino-style development environment) or our USB HID bootloader using mikroC, mikroBasic, and mikroPascal for PIC32. This kit includes a clean and regulated power supply block through the USB Type-C (USB-C) connector. All communication

methods that mikroBUS™ itself supports are on this board, including the well-established mikroBUS™ socket, user-configurable buttons, and LED indicators. Flip&Click PIC32MZ development kit allows 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.

Flip&Click PIC32MZ double image

Microcontroller Overview

MCU Card / MCU

default

Architecture

PIC32

MCU Memory (KB)

2048

Silicon Vendor

Microchip

Pin count

100

RAM (Bytes)

524288

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.

Solar energy Click accessories-1 image

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.

Solar energy Click accessories-2 image

Used MCU Pins

mikroBUS™ mapper

Buck Enable
RB11
AN
NC
NC
RST
Chip Enable
RA0
CS
NC
NC
SCK
NC
NC
MISO
NC
NC
MOSI
Power Supply
3.3V
3.3V
Ground
GND
GND
NC
NC
PWM
Battery OK Indication
RD9
INT
NC
NC
TX
NC
NC
RX
NC
NC
SCL
NC
NC
SDA
NC
NC
5V
Ground
GND
GND
1

Take a closer look

Click board™ Schematic

Solar energy click Schematic schematic

Step by step

Project assembly

Flip&Click PIC32MZ front image hardware assembly

Start by selecting your development board and Click board™. Begin with the Flip&Click PIC32MZ as your development board.

Flip&Click PIC32MZ front image hardware assembly
GNSS2 Click front image hardware assembly
Prog-cut hardware assembly
GNSS2 Click complete accessories setup image hardware assembly
Flip&Click PIC32MZ MB1 Access - 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
Flip&Click PIC32MZ MCU step 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

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 function

  • solarenergy_charge_disable  - Charge disable functions

  • solarenergy_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

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