Expand 16 Click

How does it work?

Expand 16 Click is based on the FXL6408, a fully configurable 8-bit GPIO expander from onsemi. The input default values can be programmed independently, allowing customized input detection. All inputs can be configured with pull−up or pull−down resistors to pre−bias the inputs in open−drain or non−driven applications. The FXL6408 is designed to allow voltage translation from levels as low as 1.65V and up to 4.0V. For this purpose, you can supply the FXL6408 with an external voltage source over the VEXT terminal. The choice between the external voltage and the 3.3V from the mikroBUS™ socket for the voltage reference input of the I/O expander can be set over the VDDIO SEL jumper.

Expand 16 Click uses a standard 2-wire I2C interface to communicate with the host MCU, supporting clock frequency up to 400kHz. The I2C address can be selected over the ADDR SEL jumper. The FXL6408 has three reset options: power-on reset, over the software, and the RST pin by writing the logic LOW. When the event occurs, the I/O expander will assert the host MCU over the interrupt INT pin.

This Click board™ can be operated only with a 3.3V logic voltage level. The board must perform appropriate logic voltage level conversion before using MCUs with different logic levels. Also, it comes equipped with a library containing functions and an example code that can be used as a reference for further development.

Specifications

Pinout diagram

This table shows how the pinout on Expand 16 Click corresponds to the pinout on the mikroBUS™ socket (the latter shown in the two middle columns).

Notes	Pin					Pin	Notes
	NC	1	AN	PWM	16	NC
Reset	RST	2	RST	INT	15	INT	Interrupt
ID COMM	CS	3	CS	RX	14	NC
	NC	4	SCK	TX	13	NC
	NC	5	MISO	SCL	12	SCL	I2C Clock
	NC	6	MOSI	SDA	11	SDA	I2C Data
Power Supply	3.3V	7	3.3V	5V	10	NC
Ground	GND	8	GND	GND	9	GND	Ground

Onboard settings and indicators

Expand 16 Click electrical specifications

Software Support

We provide a library for the Expand 16 Click as well as a demo application (example), developed using MIKROE compilers. The demo can run on all the main MIKROE development boards.

Package can be downloaded/installed directly from NECTO Studio Package Manager(recommended), downloaded from our LibStock™ or found on Mikroe github account.

Library Description

This library contains API for Expand 16 Click driver.

Key functions

• expand16_write_reg Expand 16 register write function.

• expand16_set_io_dir Expand 16 set pin input or output direction function.

• expand16_set_output_state Expand 16 set output pins state function.

Example Description

This example demonstrates the use of Expand 16 click board by setting and reading the ports state.

void application_task ( void )  
 { 
     uint8_t tmp_data = 0; 

     log_printf( &logger, "Output pins state: HIGH rn" ); 
     log_printf( &logger, "- - - - - - - - - - - - -rn" ); 
     expand16_set_output_state( &expand16, EXPAND16_PIN_MASK_NONE, EXPAND16_PIN_MASK_GPIO_4 |  
                                           EXPAND16_PIN_MASK_GPIO_5 | EXPAND16_PIN_MASK_GPIO_6 |  
                                           EXPAND16_PIN_MASK_GPIO_7 ); 
     expand16_read_reg( &expand16, EXPAND16_REG_INPUT_STATE, &tmp_data );  
     show_input_pin_state( tmp_data ); 
     Delay_ms( 2000 ); 

     log_printf( &logger, "Output pins state: LOW rn" ); 
     log_printf( &logger, "- - - - - - - - - - - - -rn" ); 
     expand16_set_output_state( &expand16, EXPAND16_PIN_MASK_GPIO_4 | EXPAND16_PIN_MASK_GPIO_5 |  
                                           EXPAND16_PIN_MASK_GPIO_6 | EXPAND16_PIN_MASK_GPIO_7,  
                                           EXPAND16_PIN_MASK_NONE ); 
     expand16_read_reg( &expand16, EXPAND16_REG_INPUT_STATE, &tmp_data );  
     show_input_pin_state( tmp_data ); 
     Delay_ms( 2000 ); 
 }

The full application code, and ready to use projects can be installed directly from NECTO Studio Package Manager(recommended), downloaded from our LibStock™ or found on Mikroe github account.

Other Mikroe Libraries used in the example:

• MikroSDK.Board
• MikroSDK.Log
• Click.Expand16

Additional notes and informations

Depending on the development board you are using, you may need USB UART click, USB UART 2 Click or RS232 Click to connect to your PC, for development systems with no UART to USB interface available on the board. UART terminal is available in all MIKROE compilers.

mikroSDK

This Click board™ is supported with mikroSDK - MIKROE Software Development Kit. To ensure proper operation of mikroSDK compliant Click board™ demo applications, mikroSDK should be downloaded from the LibStock and installed for the compiler you are using.

For more information about mikroSDK, visit the official page.