Upgrade your I/O control with TCA6424A and PIC18F57Q43
From limited to limitless
Published Feb 13, 2024
Click board™
EXPAND 5 Click
Dev. board
Curiosity Nano with PIC18F57Q43
Compiler
NECTO Studio
MCU
PIC18F57Q43
Our port expander solution simplifies and amplifies your I/O capabilities, enabling seamless expansion of pins for diverse applications, from automation and IoT to robotics and prototyping
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Hardware Overview
How does it work?
EXPAND 5 Click is based on the TCA6424A, low-voltage 24-bit I2C, and SMBus I/O expander from Texas Instruments. This 24-bit I/O expander for the two-line bidirectional bus is designed to provide general-purpose remote I/O expansion for most microcontroller families via the 400-kHz fast I2C bus. This Click board™ features on-board I2C address jumpers, pull-up resistors, power supply bypass capacitor, and power LED. It operates over a flexible power supply voltage range of 1.65V to 5.5V, which makes it suitable for 3.3V and 5V microcontrollers. At power-on, the I/O pins are configured as inputs. However, the microcontroller can enable the I/Os as either inputs or outputs by writing to the I/O configuration bits. The data for each input or output is kept in the corresponding input or output register. The polarity of the Input Port register can be inverted with the Polarity Inversion register. The microcontroller can reset the TCA6424A in the event of a timeout or other
improper operation by asserting a low in the RESET input. The power-on reset puts the registers in their default state and initializes the I2C interface. The RESET pin causes the same reset/initialization to occur without depowering the part. This Click board™ also has an open-drain interrupt (INT) output that is activated when any input state differs from its corresponding Input Port register state and is used to indicate to the microcontroller that an input state has changed. By sending an interrupt signal on this line, the remote I/O can inform the microcontroller if there is incoming data on its ports without having to communicate via the I2C bus. Thus, the TCA6424A can remain a simple slave device. The TCA6424A communicates with MCU using the standard I2C 2-wire interface. The TCA6424A can respond to one of two 7-bit I2C Bus Slave addresses. The first 6 bits (MSBs) have been factory programmed to 010001. The address pin, ADDR (Pin 26) is
programmed by the user and determines the LSB of the slave address and it can be selected by onboard SMD jumper labeled as ADDR SEL allowing selection of the slave address LSB. The last bit of the slave address defines the operation (read or write) to be performed. A high (1) selects a read operation, while a low (0) selects a write operation. This Click board™ can be supplied and interfaced with both 3.3V and 5V without the need for any external components. The onboard SMD jumper labeled as VCC SEL allows voltage selection for interfacing with both 3.3V and 5V microcontrollers. More information about the TCA6424A can be found in the attached datasheet. However, this Click board™ comes equipped with a library that contains easy to use functions and a usage example that may be used as a reference for the development.
Features overview
Development board
PIC18F57Q43 Curiosity Nano evaluation kit is a cutting-edge hardware platform designed to evaluate microcontrollers within the PIC18-Q43 family. Central to its design is the inclusion of the powerful PIC18F57Q43 microcontroller (MCU), offering advanced functionalities and robust performance. Key features of this evaluation kit include a yellow user LED and a responsive
mechanical user switch, providing seamless interaction and testing. The provision for a 32.768kHz crystal footprint ensures precision timing capabilities. With an onboard debugger boasting a green power and status LED, programming and debugging become intuitive and efficient. Further enhancing its utility is the Virtual serial port (CDC) and a debug GPIO channel (DGI
GPIO), offering extensive connectivity options. Powered via USB, this kit boasts an adjustable target voltage feature facilitated by the MIC5353 LDO regulator, ensuring stable operation with an output voltage ranging from 1.8V to 5.1V, with a maximum output current of 500mA, subject to ambient temperature and voltage constraints.
Microcontroller Overview
MCU Card / MCU
Architecture
PIC
MCU Memory (KB)
128
Silicon Vendor
Microchip
Pin count
48
RAM (Bytes)
8196
You complete me!
Accessories
Curiosity Nano Base for Click boards is a versatile hardware extension platform created to streamline the integration between Curiosity Nano kits and extension boards, tailored explicitly for the mikroBUS™-standardized Click boards and Xplained Pro extension boards. This innovative base board (shield) offers seamless connectivity and expansion possibilities, simplifying experimentation and development. Key features include USB power compatibility from the Curiosity Nano kit, alongside an alternative external power input option for enhanced flexibility. The onboard Li-Ion/LiPo charger and management circuit ensure smooth operation for battery-powered applications, simplifying usage and management. Moreover, the base incorporates a fixed 3.3V PSU dedicated to target and mikroBUS™ power rails, alongside a fixed 5.0V boost converter catering to 5V power rails of mikroBUS™ sockets, providing stable power delivery for various connected devices.
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 Curiosity Nano with PIC18F57Q43 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 EXPAND 5 Click driver.
Key functions:
expand5_write_all_banks- Set all OUTPUT pins' logic levels in all banks functionexpand5_get_bank_pol- Get all pin polarity ( normal/inverted ) settings from one bank functionexpand5_get_pin_dir- Get a single pin's direction ( I/O ) setting 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
* \brief Expand5 Click example
*
* # Description
* This example demonstrates the use of Expand 5 Click board.
*
* The demo application is composed of two sections :
*
* ## Application Init
* Initalizes I2C driver, resets the device, configures all pins as output and makes an initial log.
*
* ## Application Task
* This example shows the capabilities of the EXPAND 5 click by toggling each of the 24 available pins.
*
* \author MikroE Team
*
*/
// ------------------------------------------------------------------- INCLUDES
#include "board.h"
#include "log.h"
#include "expand5.h"
// ------------------------------------------------------------------ VARIABLES
static expand5_t expand5;
static log_t logger;
uint8_t pin_num;
uint8_t bank_out = 0x00;
uint8_t bank_low = 0x00;
char log_txt[ 50 ];
// ------------------------------------------------------ APPLICATION FUNCTIONS
void application_init ( void )
{
log_cfg_t log_cfg;
expand5_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.
expand5_cfg_setup( &cfg );
EXPAND5_MAP_MIKROBUS( cfg, MIKROBUS_1 );
expand5_init( &expand5, &cfg );
Delay_ms( 100 );
log_printf( &logger, "------------------- \r\n" );
log_printf( &logger, " EXPAND 5 click \r\n" );
log_printf( &logger, "------------------- \r\n" );
expand5_reset( &expand5 );
expand5_set_all_dir( &expand5, bank_out, bank_out, bank_out );
Delay_ms( 100 );
log_printf( &logger, " Pins configured \r\n" );
log_printf( &logger, " as output \r\n" );
log_printf( &logger, "------------------- \r\n" );
}
void application_task ( void )
{
for ( pin_num = EXPAND5_P00; pin_num <= EXPAND5_P27; pin_num++ )
{
expand5_write_all_banks ( &expand5, bank_low, bank_low, bank_low );
expand5_write_pin ( &expand5, pin_num, EXPAND5_HIGH );
log_printf( &logger, "Pin %u is high \r\n", ( uint16_t ) pin_num );
Delay_ms( 200 );
expand5_write_all_banks ( &expand5, bank_low, bank_low, bank_low );
}
log_printf( &logger, "------------------- \r\n" );
Delay_ms( 1000 );
}
void main ( void )
{
application_init( );
for ( ; ; )
{
application_task( );
}
}
// ------------------------------------------------------------------------ END
Additional Support
Resources
Category:Port expander
