captouch4  2.1.0.0
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Cap Touch 4 click

Cap Touch 4 Click is a compact add-on board for wake-on-touch and activation applications. This board features the IQS211B, a single-channel capacitive controller from Azoteq, featuring ProxSense® technology for highly sensitive self-capacitance measurements. The board includes a defined circular touch-sensing area, signal conditioning for parasitic capacitance, and a low-power Sleep mode with wake-up functionality, ensuring efficient energy consumption. It communicates via the I2C interface with a fixed address of 0x47, operates at 3.3V logic, and features the new Click Snap for added flexibility.

click Product page


Click library

  • Author : Stefan Filipovic
  • Date : Apr 2024.
  • Type : I2C type

Software Support

We provide a library for the Cap Touch 4 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.

Library Description

This library contains API for Cap Touch 4 Click driver.

Standard key functions :

Example key functions :

  • captouch4_read_system_flags This function reads the system flags register.
    err_t captouch4_read_system_flags ( captouch4_t *ctx, uint8_t *sysflags );
  • captouch4_read_cap_counts This function reads the counts number directly proportional to capacitance. The system is calibrated to make the counts as sensitive as possible to changes in capacitance for relative measurements.
    err_t captouch4_read_cap_counts ( captouch4_t *ctx, uint16_t *cap_counts );
  • captouch4_read_lta This function reads the long-term averate (LTA) value. The LTA is used as reference to compare with capacitance counts.
    err_t captouch4_read_lta ( captouch4_t *ctx, uint16_t *lta );

Example Description

This example demonstrates the use of Cap Touch 4 click board by reading the proximity, touch, and movement events.

The demo application is composed of two sections :

Application Init

Initializes the driver and performs the click default configuration.

void application_init ( void )
{
log_cfg_t log_cfg;
captouch4_cfg_t captouch4_cfg;
LOG_MAP_USB_UART( log_cfg );
log_init( &logger, &log_cfg );
log_info( &logger, " Application Init " );
// Click initialization.
captouch4_cfg_setup( &captouch4_cfg );
CAPTOUCH4_MAP_MIKROBUS( captouch4_cfg, MIKROBUS_1 );
if ( I2C_MASTER_ERROR == captouch4_init( &captouch4, &captouch4_cfg ) )
{
log_error( &logger, " Communication init." );
for ( ; ; );
}
if ( CAPTOUCH4_ERROR == captouch4_default_cfg ( &captouch4 ) )
{
log_error( &logger, " Default configuration." );
for ( ; ; );
}
log_info( &logger, " Application Task " );
}

Application Task

Reads the proximity, touch, and movement events and approximately displays the results on the USB UART every 200ms. The capacitance counts and the long-term average values are also displayed.

void application_task ( void )
{
uint8_t sys_flags = 0;
uint8_t movement = 0;
uint16_t cap_counts = 0;
uint16_t lta = 0;
if ( CAPTOUCH4_OK == captouch4_read_system_flags ( &captouch4, &sys_flags ) )
{
if ( sys_flags & CAPTOUCH4_SYSFLAGS0_PROX )
{
log_printf( &logger, " Proximity detected\r\n" );
}
if ( sys_flags & CAPTOUCH4_SYSFLAGS0_TOUCH )
{
log_printf( &logger, " Touch detected\r\n" );
}
if ( sys_flags & CAPTOUCH4_SYSFLAGS0_MOVEMENT )
{
if ( CAPTOUCH4_OK == captouch4_read_movement ( &captouch4, &movement ) )
{
log_printf( &logger, " Movement detected: %u\r\n", ( uint16_t ) movement );
}
}
if ( ( sys_flags & CAPTOUCH4_SYSFLAGS0_MOVEMENT ) ||
( sys_flags & CAPTOUCH4_SYSFLAGS0_PROX ) ||
( sys_flags & CAPTOUCH4_SYSFLAGS0_TOUCH ) )
{
if ( CAPTOUCH4_OK == captouch4_read_cap_counts ( &captouch4, &cap_counts ) )
{
log_printf( &logger, " Capacitance counts: %u\r\n", cap_counts );
}
if ( CAPTOUCH4_OK == captouch4_read_lta ( &captouch4, &lta ) )
{
log_printf( &logger, " Long-term average: %u\r\n\n", lta );
}
}
else
{
log_printf( &logger, " No detected events\r\n\n" );
}
}
Delay_ms ( 200 );
}

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.CapTouch4

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.


captouch4_read_cap_counts
err_t captouch4_read_cap_counts(captouch4_t *ctx, uint16_t *cap_counts)
Cap Touch 4 read cap counts function.
CAPTOUCH4_SYSFLAGS0_MOVEMENT
#define CAPTOUCH4_SYSFLAGS0_MOVEMENT
Cap Touch 4 SYSFLAGS0 register setting.
Definition: captouch4.h:124
captouch4_read_lta
err_t captouch4_read_lta(captouch4_t *ctx, uint16_t *lta)
Cap Touch 4 read lta function.
captouch4_init
err_t captouch4_init(captouch4_t *ctx, captouch4_cfg_t *cfg)
Cap Touch 4 initialization function.
captouch4_cfg_setup
void captouch4_cfg_setup(captouch4_cfg_t *cfg)
Cap Touch 4 configuration object setup function.
application_task
void application_task(void)
Definition: main.c:66
captouch4_read_system_flags
err_t captouch4_read_system_flags(captouch4_t *ctx, uint8_t *sysflags)
Cap Touch 4 read system flags function.
CAPTOUCH4_MAP_MIKROBUS
#define CAPTOUCH4_MAP_MIKROBUS(cfg, mikrobus)
MikroBUS pin mapping.
Definition: captouch4.h:170
captouch4_t
Cap Touch 4 Click context object.
Definition: captouch4.h:183
captouch4_read_movement
err_t captouch4_read_movement(captouch4_t *ctx, uint8_t *movement)
Cap Touch 4 read movement function.
CAPTOUCH4_ERROR
@ CAPTOUCH4_ERROR
Definition: captouch4.h:218
CAPTOUCH4_OK
@ CAPTOUCH4_OK
Definition: captouch4.h:217
captouch4_default_cfg
err_t captouch4_default_cfg(captouch4_t *ctx)
Cap Touch 4 default configuration function.
application_init
void application_init(void)
Definition: main.c:30
captouch4_cfg_t
Cap Touch 4 Click configuration object.
Definition: captouch4.h:202
CAPTOUCH4_SYSFLAGS0_TOUCH
#define CAPTOUCH4_SYSFLAGS0_TOUCH
Definition: captouch4.h:127
CAPTOUCH4_SYSFLAGS0_PROX
#define CAPTOUCH4_SYSFLAGS0_PROX
Definition: captouch4.h:126