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CapSense 2 Click is a compact add-on board that easily integrates projected capacitive touch into user's applications. This board features the CAP1114, a multi-channel capacitive touch sensor that takes human body capacitance as an input and directly provides the real-time sensor information via the I2C serial interface from Microchip. This board contains capacitive sensing elements, a 7-segment slider, two buttons, and four LED indicators that visually detect the activation on some of these parts. This Click board™ offers reliable and accurate sensing for any application that uses capacitive touch sensing functions.
- Author : Stefan Filipovic
- Date : Dec 2021.
- Type : I2C type
We provide a library for the CapSense 2 Click as well as a demo application (example), developed using MikroElektronika compilers. The demo can run on all the main MikroElektronika development boards.
Package can be downloaded/installed directly from NECTO Studio Package Manager(recommended way), downloaded from our LibStock™ or found on Mikroe github account.
This library contains API for CapSense 2 Click driver.
capsense2_cfg_setupConfig Object Initialization function.
void capsense2_cfg_setup ( capsense2_cfg_t *cfg );capsense2_initInitialization function.
err_t capsense2_init ( capsense2_t *ctx, capsense2_cfg_t *cfg );capsense2_default_cfgClick Default Configuration function.
err_t capsense2_default_cfg ( capsense2_t *ctx );capsense2_read_registerThis function reads a data byte from the selected register by using I2C serial interface.
err_t capsense2_read_register ( capsense2_t *ctx, uint8_t reg, uint8_t *data_out );capsense2_get_alert_pinThis function returns the alert pin logic state.
uint8_t capsense2_get_alert_pin ( capsense2_t *ctx );capsense2_clear_interruptThis function clears the INT bit of the main status register if the interrupt pin is asserted.
err_t capsense2_clear_interrupt ( capsense2_t *ctx );This example demonstrates the use of CapSense 2 click board by reading and displaying the sensor's events.
The demo application is composed of two sections :
Initializes the driver and performs the click default configuration which resets the click board and links the desired LEDs to buttons and swipe sensors.
void application_init ( void )
{
log_cfg_t log_cfg; /**< Logger config object. */
capsense2_cfg_t capsense2_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.
capsense2_cfg_setup( &capsense2_cfg );
CAPSENSE2_MAP_MIKROBUS( capsense2_cfg, MIKROBUS_1 );
if ( I2C_MASTER_ERROR == capsense2_init( &capsense2, &capsense2_cfg ) )
{
log_error( &logger, " Communication init." );
for ( ; ; );
}
if ( CAPSENSE2_ERROR == capsense2_default_cfg ( &capsense2 ) )
{
log_error( &logger, " Default configuration." );
for ( ; ; );
}
log_info( &logger, " Application Task " );
}Waits for an event interrupt and displays the event on the USB UART.
void application_task ( void )
{
if ( capsense2_get_alert_pin ( &capsense2 ) )
{
uint8_t button_status = 0;
if ( CAPSENSE2_OK == capsense2_read_register ( &capsense2, CAPSENSE2_REG_BUTTON_STATUS_1, &button_status ) )
{
static uint8_t button_press_state = 0;
static uint8_t swipe_state = 0;
if ( button_status & CAPSENSE2_BUTTON_STATUS_1_UP_SLIDER )
{
if ( CAPSENSE2_BUTTON_STATUS_1_UP_SLIDER != swipe_state )
{
log_printf ( &logger, " Swipe UP \r\n\n" );
swipe_state = CAPSENSE2_BUTTON_STATUS_1_UP_SLIDER;
}
}
if ( button_status & CAPSENSE2_BUTTON_STATUS_1_DOWN_SLIDER )
{
if ( CAPSENSE2_BUTTON_STATUS_1_DOWN_SLIDER != swipe_state )
{
log_printf ( &logger, " Swipe DOWN \r\n\n" );
swipe_state = CAPSENSE2_BUTTON_STATUS_1_DOWN_SLIDER;
}
}
if ( button_status & CAPSENSE2_BUTTON_STATUS_1_BUTTON_1 )
{
if ( !( button_press_state & CAPSENSE2_BUTTON_STATUS_1_BUTTON_1 ) )
{
log_printf ( &logger, " Button 1 pressed \r\n\n" );
button_press_state |= CAPSENSE2_BUTTON_STATUS_1_BUTTON_1;
}
}
if ( button_status & CAPSENSE2_BUTTON_STATUS_1_BUTTON_2 )
{
if ( !( button_press_state & CAPSENSE2_BUTTON_STATUS_1_BUTTON_2 ) )
{
log_printf ( &logger, " Button 2 pressed \r\n\n" );
button_press_state |= CAPSENSE2_BUTTON_STATUS_1_BUTTON_2;
}
}
capsense2_clear_interrupt ( &capsense2 );
// check if buttons are released
if ( CAPSENSE2_OK == capsense2_read_register ( &capsense2, CAPSENSE2_REG_BUTTON_STATUS_1, &button_status ) )
{
if ( ( button_press_state & CAPSENSE2_BUTTON_STATUS_1_BUTTON_1 ) &&
!( button_status & CAPSENSE2_BUTTON_STATUS_1_BUTTON_1 ) )
{
log_printf ( &logger, " Button 1 released \r\n\n" );
button_press_state &= ~CAPSENSE2_BUTTON_STATUS_1_BUTTON_1;
}
if ( ( button_press_state & CAPSENSE2_BUTTON_STATUS_1_BUTTON_2 ) &&
!( button_status & CAPSENSE2_BUTTON_STATUS_1_BUTTON_2 ) )
{
log_printf ( &logger, " Button 2 released \r\n\n" );
button_press_state &= ~CAPSENSE2_BUTTON_STATUS_1_BUTTON_2;
}
}
// check if swipe event is finished and display the slider position
uint8_t slider = 0;
if ( CAPSENSE2_OK == capsense2_read_register ( &capsense2, CAPSENSE2_REG_SLIDER_POSITION_DATA, &slider ) )
{
if ( slider )
{
log_printf ( &logger, " Slider position: %u \r\n\n", ( uint16_t ) slider );
}
else
{
swipe_state = 0;
}
}
}
capsense2_clear_interrupt ( &capsense2 );
}
}The full application code, and ready to use projects can be installed directly from NECTO Studio Package Manager(recommended way), downloaded from our LibStock™ or found on Mikroe github account.
Other Mikroe Libraries used in the example:
- MikroSDK.Board
- MikroSDK.Log
- Click.CapSense2
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 MikroElektronika compilers.