Expand I/O capabilities and streamline data management with PCAL6524 and STM32G071RB
Versatile I/O expansion: Unlock I/O potential with ease!
Published Oct 08, 2024
Click board™
Expand 10 Click
Dev Board
Nucleo 64 with STM32G071RB MCU
Compiler
NECTO Studio
MCU
STM32G071RB
Transform your electronics design with our I/O expansion solution, offering a reliable and efficient means for connecting and controlling a wide range of devices and peripherals
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Hardware Overview
How does it work?
Expand 10 Click is based on the PCAL6524, a 24-bit ultra-low-voltage translating general-purpose I/O expander from NXP Semiconductors. This port expander is a simple solution for when additional I/Os are needed while keeping interconnections to a minimum. It is particularly great for system monitoring applications, industrial controllers, and portable equipment. The PCAL6524 has a built-in level shifting feature that makes it highly flexible in power supply systems where communication between incompatible I/O voltages is required. The PCAL6524 implements Agile I/O features designed to enhance the I/O. These additional features are programmable output drive strength, latchable inputs, programmable
pull-up/pull-down resistors, maskable interrupt, interrupt status register, and programmable open-drain or push-pull outputs. Expand 10 Click communicates with MCU using the standard I2C 2-Wire interface to read data and configure settings, supporting a Fast Mode Plus operation up to 1MHz. At the Power-On sequence, the I/Os are configured as inputs. However, the host MCU can enable the I/Os as inputs or outputs by writing to the I/O configuration bits. In addition to I2C communication, two GPIO pins connected to the mikroBUS™ socket pins are also used. The reset pin routed to the RST pin of the mikroBUS™ socket, is used to place the PCAL6524 registers in their default state, while the interrupt, routed
to the INT pin of the mikroBUS™ socket, may be configured as an interrupt to notify the host MCU of incoming data on any port. Besides, it also allows the choice of the least significant bit of its I2C slave address by positioning the SMD jumper labeled ADDR SEL to an appropriate position marked as 1 and 0. This Click board™ can operate with either 3.3V or 5V logic voltage levels selected via the VCC SEL jumper. This way, both 3.3V and 5V capable MCUs can use the communication lines properly. Also, this Click board™ comes equipped with a library containing easy-to-use 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.
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 Expand 10 Click driver.
Key functions:
expand10_set_pin_direction- This function sets the direction of the selected pinsexpand10_set_pin_value- This function sets the value of the selected pinsexpand10_read_port_value- This function reads the value of the selected port input pins
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 Expand10 Click example
*
* # Description
* This example demonstrates the use of Expand 10 click board.
*
* The demo application is composed of two sections :
*
* ## Application Init
* Initializes the driver and performs the click default configuration which sets the first two ports
* as output and the third port as input with pull-down enabled.
*
* ## Application Task
* Sets the pins of the first two ports and then reads and displays the status of
* all ports on the USB UART approximately once per second.
*
* @author Stefan Filipovic
*
*/
#include "board.h"
#include "log.h"
#include "expand10.h"
static expand10_t expand10;
static log_t logger;
void application_init ( void )
{
log_cfg_t log_cfg; /**< Logger config object. */
expand10_cfg_t expand10_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.
expand10_cfg_setup( &expand10_cfg );
EXPAND10_MAP_MIKROBUS( expand10_cfg, MIKROBUS_1 );
err_t init_flag = expand10_init( &expand10, &expand10_cfg );
if ( I2C_MASTER_ERROR == init_flag )
{
log_error( &logger, " Application Init Error. " );
log_info( &logger, " Please, run program again... " );
for ( ; ; );
}
init_flag = expand10_default_cfg ( &expand10 );
if ( EXPAND10_ERROR == init_flag )
{
log_error( &logger, " Default Config Error. " );
log_info( &logger, " Please, run program again... " );
for ( ; ; );
}
log_info( &logger, " Application Task " );
}
void application_task ( void )
{
uint8_t port_value = 0;
for ( uint16_t pin_num = EXPAND10_PIN_0_MASK; pin_num <= EXPAND10_PIN_7_MASK; pin_num <<= 1 )
{
expand10_set_all_pins_value( &expand10, pin_num );
expand10_read_port_value( &expand10, EXPAND10_PORT_0, &port_value );
log_printf( &logger, " Status P0 (output): 0x%.2X\r\n", ( uint16_t ) port_value );
expand10_read_port_value( &expand10, EXPAND10_PORT_1, &port_value );
log_printf( &logger, " Status P1 (output): 0x%.2X\r\n", ( uint16_t ) port_value );
expand10_read_port_value( &expand10, EXPAND10_PORT_2, &port_value );
log_printf( &logger, " Status P2 (input) : 0x%.2X\r\n\r\n", ( uint16_t ) port_value );
Delay_ms( 1000 );
}
}
void main ( void )
{
application_init( );
for ( ; ; )
{
application_task( );
}
}
// ------------------------------------------------------------------------ END
