ldctouch  2.0.0.0
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LDC Touch click

LDC Touch Click is a compact add-on board optimized for inductive touch applications. This board features the LDC3114-Q1, a four-channel inductance-to-digital converter for low-power proximity and touch-button sensing from Texas Instruments. It comes with an adjustable sensitivity per input channel and operational power mode selection and measures frequency shifts caused by micro-deflection in the conductive targets formed by button presses. These presses are reported through a compatible I2C interface beside four LED indicators for its visual indication. This Click boardâ„¢ enables touch button design for human-machine interface and precise linear position sensing of metal targets for automotive, consumer, and industrial applications by allowing access to the raw data representing the inductance value.

click Product page


Click library

  • Author : Stefan Filipovic
  • Date : May 2022.
  • Type : I2C type

Software Support

We provide a library for the LDC Touch 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 LDC Touch Click driver.

Standard key functions :

Example key functions :

Example Description

This example demonstrates the use of LDC Touch click board by configuring

the buttons to trigger on finger press, and reading the buttons state in the loop.

The demo application is composed of two sections :

Application Init

Initializes the driver and configures the buttons to be active on finger press.

void application_init ( void )
{
log_cfg_t log_cfg;
ldctouch_cfg_t ldctouch_cfg;
LOG_MAP_USB_UART( log_cfg );
log_init( &logger, &log_cfg );
log_info( &logger, " Application Init " );
// Click initialization.
ldctouch_cfg_setup( &ldctouch_cfg );
LDCTOUCH_MAP_MIKROBUS( ldctouch_cfg, MIKROBUS_1 );
if ( I2C_MASTER_ERROR == ldctouch_init( &ldctouch, &ldctouch_cfg ) )
{
log_error( &logger, " Communication init." );
for ( ; ; );
}
if ( LDCTOUCH_ERROR == ldctouch_default_cfg ( &ldctouch ) )
{
log_error( &logger, " Default configuration." );
for ( ; ; );
}
log_info( &logger, " Application Task " );
}

Application Task

Waits for the button active event interrupt and then reads and displays the buttons

state and their raw data on the USB UART every 200ms approximately.

void application_task ( void )
{
static bool button_active = true;
if ( !ldctouch_get_int_pin ( &ldctouch ) )
{
ldctouch_data_t button_data;
if ( LDCTOUCH_OK == ldctouch_get_data ( &ldctouch, &button_data ) )
{
button_active = true;
log_printf ( &logger, " Active button: -" );
for ( uint8_t cnt = 0; cnt < 4; cnt++ )
{
if ( button_data.out_state & ( 1 << cnt ) )
{
log_printf ( &logger, " %u - ", ( uint16_t ) cnt );
}
}
log_printf ( &logger, "\r\n Button 0 raw data: %d\r\n", button_data.ch0_raw_button );
log_printf ( &logger, " Button 1 raw data: %d\r\n", button_data.ch1_raw_button );
log_printf ( &logger, " Button 2 raw data: %d\r\n", button_data.ch2_raw_button );
log_printf ( &logger, " Button 3 raw data: %d\r\n\n", button_data.ch3_raw_button );
Delay_ms ( 200 );
}
}
else
{
if ( button_active )
{
button_active = false;
log_printf ( &logger, " Active button: - none -\r\n" );
}
}
}

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.LDCTouch

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.


ldctouch_get_data
err_t ldctouch_get_data(ldctouch_t *ctx, ldctouch_data_t *button_data)
LDC Touch get data function.
ldctouch_get_int_pin
uint8_t ldctouch_get_int_pin(ldctouch_t *ctx)
LDC Touch get int pin function.
ldctouch_data_t::ch0_raw_button
int16_t ch0_raw_button
Definition: ldctouch.h:293
ldctouch_data_t::ch1_raw_button
int16_t ch1_raw_button
Definition: ldctouch.h:294
application_task
void application_task(void)
Definition: main.c:65
ldctouch_cfg_t
LDC Touch Click configuration object.
Definition: ldctouch.h:270
LDCTOUCH_ERROR
@ LDCTOUCH_ERROR
Definition: ldctouch.h:307
ldctouch_data_t::ch2_raw_button
int16_t ch2_raw_button
Definition: ldctouch.h:295
LDCTOUCH_OK
@ LDCTOUCH_OK
Definition: ldctouch.h:306
ldctouch_t
LDC Touch Click context object.
Definition: ldctouch.h:249
ldctouch_data_t::out_state
uint8_t out_state
Definition: ldctouch.h:292
ldctouch_data_t::ch3_raw_button
int16_t ch3_raw_button
Definition: ldctouch.h:296
ldctouch_cfg_setup
void ldctouch_cfg_setup(ldctouch_cfg_t *cfg)
LDC Touch configuration object setup function.
ldctouch_init
err_t ldctouch_init(ldctouch_t *ctx, ldctouch_cfg_t *cfg)
LDC Touch initialization function.
application_init
void application_init(void)
Definition: main.c:29
ldctouch_set_operation_mode
err_t ldctouch_set_operation_mode(ldctouch_t *ctx, uint8_t mode)
LDC Touch set operation mode function.
ldctouch_default_cfg
err_t ldctouch_default_cfg(ldctouch_t *ctx)
LDC Touch default configuration function.
LDCTOUCH_MAP_MIKROBUS
#define LDCTOUCH_MAP_MIKROBUS(cfg, mikrobus)
MikroBUS pin mapping.
Definition: ldctouch.h:232
ldctouch_data_t
LDC Touch Click data object.
Definition: ldctouch.h:290