Optimize the efficiency of your control systems and smart solutions with our multi-port I/O expander, enabling precise input and output management for data regulation and energy conservation
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Hardware Overview
How does it work?
Expand 15 Click is based on the TCAL6416, a general-purpose I/O expander from Texas Instruments. The TCAL6416 comes in one P-port configuration and allows easy addition of I/O through a standard I2C serial interface. Its digital core consists of 8-bit data registers, allowing users to configure the I/O port characteristics. The I/Os are configured as inputs at Power-On or after a Reset condition. However, the host controller can configure the I/Os as either inputs or outputs by writing to the Configuration registers. The data for each input or output is kept in the corresponding Input Port or Output Port register, with the possibility to invert the polarity of the Input Port with the Polarity Inversion register. The P-port channels configured as outputs can sink up to 25mA for directly driving LEDs, but the current
must be limited externally with additional resistance. Additionally, the TCAL6416 has Agile I/O functionality specifically targeted to enhance the I/O ports, including programmable output drive strength, programmable pull-up and pull-down resistors, latchable inputs, maskable interrupts, interrupt status register, and programmable open-drain or push-pull outputs. These configuration registers improve the I/O by increasing flexibility and allowing users to optimize their design for power consumption, speed, and EMI. This Click board™ communicates with MCU using the standard I2C 2-Wire interface to read data and configure settings with a maximum frequency of 1MHz. Also, the TCAL6416 allows choosing the least significant bits (LSB) of its I2C slave address using the SMD jumper labeled ADDR SEL. It also
possesses a general reset signal routed on the RST pin of the mikroBUS™ socket to reset the TCAL6416 and an additional interrupt signal routed on the INT pin of the mikroBUS™ socket whenever an input port changes state. This Click board™ can only be operated with a 3.3V logic voltage level. Additionally, there is a possibility for the TCAL6416 power supply selection via jumper labeled VCCP SEL to supply the TCAL6416 from 1.08V to 3.6V external power supply (V pin) or with 3V3 mikroBUS™ power rail. The board must perform appropriate logic voltage level conversion before using MCUs with different logic levels. 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
Arduino Mega 2560 is a robust microcontroller platform built around the ATmega 2560 chip. It has extensive capabilities and boasts 54 digital input/output pins, including 15 PWM outputs, 16 analog inputs, and 4 UARTs. With a 16MHz crystal
oscillator ensuring precise timing, it offers seamless connectivity via USB, a convenient power jack, an ICSP header, and a reset button. This all-inclusive board simplifies microcontroller projects; connect it to your computer via USB or power it up
using an AC-to-DC adapter or battery. Notably, the Mega 2560 maintains compatibility with a wide range of shields crafted for the Uno, Duemilanove, or Diecimila boards, ensuring versatility and ease of integration.
Microcontroller Overview
MCU Card / MCU

Architecture
AVR
MCU Memory (KB)
256
Silicon Vendor
Microchip
Pin count
100
RAM (Bytes)
8192
You complete me!
Accessories
Click Shield for Arduino Mega comes equipped with four mikroBUS™ sockets, with two in the form of a Shuttle connector, allowing all the Click board™ devices to be interfaced with the Arduino Mega board with no effort. Featuring an AVR 8-bit microcontroller with advanced RISC architecture, 54 digital I/O pins, and Arduino™ compatibility, the Arduino Mega board offers limitless possibilities for prototyping and creating diverse applications. This board is controlled and powered conveniently through a USB connection to program and debug the Arduino Mega board efficiently out of the box, with an additional USB cable connected to the USB B port on the board. Simplify your project development with the integrated ATmega16U2 programmer and unleash creativity using the extensive I/O options and expansion capabilities. There are eight switches, which you can use as inputs, and eight LEDs, which can be used as outputs of the MEGA2560. In addition, the shield features the MCP1501, a high-precision buffered voltage reference from Microchip. This reference is selected by default over the EXT REF jumper at the bottom of the board. You can choose an external one, as you would usually do with an Arduino Mega board. There is also a GND hook for testing purposes. Four additional LEDs are PWR, LED (standard pin D13), RX, and TX LEDs connected to UART1 (mikroBUS™ 1 socket). 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 Arduino Mega board with Click Shield for Arduino Mega, 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
Click board™ Schematic

Step by step
Project 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 Expand 15 Click driver.
Key functions:
expand15_hw_reset
- Expand 15 hardware reset functionexpand15_get_in_pin_state
- Expand 15 get input pin state functionexpand15_set_out_pin_state
- Expand 15 set output pin state 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 main.c
* @brief Expand 15 Click example
*
* # Description
* This example demonstrates the use of Expand 15 Click board by setting and reading
* the ports state.
*
* The demo application is composed of two sections :
*
* ## Application Init
* Initializes the driver and performs the Click default configuration which sets
* half of the port 0 and port 1 pins as output ( P00, P02, P04, P06, P10, P12, P14 and P16) and the
* half of the port 0 and port 1 pins as inputs ( P01, P03, P05, P07, P11, P13, P15 and P17).
*
* ## Application Task
* Sets the state of the output pins of one port and then reads the status of input pins of that port
* and displays the results on the USB UART approximately 2 seconds.
*
* @note
* In order for this example to work as intended it is necessary to connect the input and output pins
* eg. P00 and P01, P02 and P03 etc. Floating input pins will be shown as a high state.
*
* @author Stefan Ilic
*
*/
#include "board.h"
#include "log.h"
#include "expand15.h"
static expand15_t expand15;
static log_t logger;
void application_init ( void )
{
log_cfg_t log_cfg; /**< Logger config object. */
expand15_cfg_t expand15_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.
expand15_cfg_setup( &expand15_cfg );
EXPAND15_MAP_MIKROBUS( expand15_cfg, MIKROBUS_1 );
if ( I2C_MASTER_ERROR == expand15_init( &expand15, &expand15_cfg ) )
{
log_error( &logger, " Communication init." );
for ( ; ; );
}
if ( EXPAND15_ERROR == expand15_default_cfg ( &expand15 ) )
{
log_error( &logger, " Default configuration." );
for ( ; ; );
}
log_info( &logger, " Application Task " );
log_printf( &logger, "- - - - - - - - - - - - - - - - - - - - - - - - - - \r\n" );
}
void application_task ( void )
{
uint8_t output_pin_state;
uint8_t input_pin_state;
// Setting port0 output pin ( P00, P02, P04 and P06 ) to high
output_pin_state = EXPAND15_PIN_00_MASK | EXPAND15_PIN_02_MASK | EXPAND15_PIN_04_MASK | EXPAND15_PIN_06_MASK;
expand15_set_out_pin_state( &expand15, EXPAND15_PORT_0, output_pin_state );
Delay_ms ( 10 );
// Checking state of the input pins on port0
expand15_get_in_pin_state( &expand15, EXPAND15_PORT_0, &input_pin_state );
log_printf( &logger, "OUTPUT PINS HIGH \r\n" );
log_printf( &logger, "INPUT PINS |" );
log_printf( &logger, " P01 : %c |", ( ( input_pin_state & EXPAND15_PIN_01_MASK ) ? 'H' : 'L' ) );
log_printf( &logger, " P03 : %c |", ( ( input_pin_state & EXPAND15_PIN_03_MASK ) ? 'H' : 'L' ) );
log_printf( &logger, " P05 : %c |", ( ( input_pin_state & EXPAND15_PIN_05_MASK ) ? 'H' : 'L' ) );
log_printf( &logger, " P07 : %c \r\n", ( ( input_pin_state & EXPAND15_PIN_07_MASK ) ? 'H' : 'L' ) );
Delay_ms ( 500 );
// Setting port0 output pin ( P00, P02, P04 and P06 ) to low
output_pin_state = EXPAND15_ALL_PINS_OFF;
expand15_set_out_pin_state( &expand15, EXPAND15_PORT_0, output_pin_state );
Delay_ms ( 10 );
// Checking state of the input pins on port0
expand15_get_in_pin_state( &expand15, EXPAND15_PORT_0, &input_pin_state );
log_printf( &logger, "OUTPUT PINS LOW \r\n" );
log_printf( &logger, "INPUT PINS |" );
log_printf( &logger, " P01 : %c |", ( ( input_pin_state & EXPAND15_PIN_01_MASK ) ? 'H' : 'L' ) );
log_printf( &logger, " P03 : %c |", ( ( input_pin_state & EXPAND15_PIN_03_MASK ) ? 'H' : 'L' ) );
log_printf( &logger, " P05 : %c |", ( ( input_pin_state & EXPAND15_PIN_05_MASK ) ? 'H' : 'L' ) );
log_printf( &logger, " P07 : %c \r\n", ( ( input_pin_state & EXPAND15_PIN_07_MASK ) ? 'H' : 'L' ) );
log_printf( &logger, "- - - - - - - - - - - - - - - - - - - - - - - - - - \r\n" );
Delay_ms ( 1000 );
Delay_ms ( 1000 );
// Setting port1 output pin ( P10, P12, P14 and P01 ) to high
output_pin_state = EXPAND15_PIN_10_MASK | EXPAND15_PIN_12_MASK | EXPAND15_PIN_14_MASK | EXPAND15_PIN_16_MASK;
expand15_set_out_pin_state( &expand15, EXPAND15_PORT_1, output_pin_state );
Delay_ms ( 10 );
// Checking state of the input pins on port1
expand15_get_in_pin_state( &expand15, EXPAND15_PORT_1, &input_pin_state );
log_printf( &logger, "OUTPUT PINS HIGH \r\n" );
log_printf( &logger, "INPUT PINS |" );
log_printf( &logger, " P11 : %c |", ( ( input_pin_state & EXPAND15_PIN_11_MASK ) ? 'H' : 'L' ) );
log_printf( &logger, " P13 : %c |", ( ( input_pin_state & EXPAND15_PIN_13_MASK ) ? 'H' : 'L' ) );
log_printf( &logger, " P15 : %c |", ( ( input_pin_state & EXPAND15_PIN_15_MASK ) ? 'H' : 'L' ) );
log_printf( &logger, " P17 : %c \r\n", ( ( input_pin_state & EXPAND15_PIN_17_MASK ) ? 'H' : 'L' ) );
Delay_ms ( 500 );
// Setting port1 output pin ( P10, P12, P14 and P16 ) to low
output_pin_state = EXPAND15_ALL_PINS_OFF;
expand15_set_out_pin_state( &expand15, EXPAND15_PORT_1, output_pin_state );
Delay_ms ( 10 );
// Checking state of the input pins on port1
expand15_get_in_pin_state( &expand15, EXPAND15_PORT_1, &input_pin_state );
log_printf( &logger, "OUTPUT PINS LOW \r\n" );
log_printf( &logger, "INPUT PINS |" );
log_printf( &logger, " P11 : %c |", ( ( input_pin_state & EXPAND15_PIN_11_MASK ) ? 'H' : 'L' ) );
log_printf( &logger, " P13 : %c |", ( ( input_pin_state & EXPAND15_PIN_13_MASK ) ? 'H' : 'L' ) );
log_printf( &logger, " P15 : %c |", ( ( input_pin_state & EXPAND15_PIN_15_MASK ) ? 'H' : 'L' ) );
log_printf( &logger, " P17 : %c \r\n", ( ( input_pin_state & EXPAND15_PIN_17_MASK ) ? 'H' : 'L' ) );
log_printf( &logger, "- - - - - - - - - - - - - - - - - - - - - - - - - - \r\n" );
Delay_ms ( 1000 );
Delay_ms ( 1000 );
}
int main ( void )
{
/* Do not remove this line or clock might not be set correctly. */
#ifdef PREINIT_SUPPORTED
preinit();
#endif
application_init( );
for ( ; ; )
{
application_task( );
}
return 0;
}
// ------------------------------------------------------------------------ END
Additional Support
Resources
Category:Port expander