qtouch_demo.c File Reference

SAM4S-Xplained QTouch and LED demonstration.

Copyright (c) 2012-2018 Microchip Technology Inc. and its subsidiaries.

#include "asf.h"
#include "conf_example.h"

Macros
#define	DEFAULT_LED_FREQ   4
	Set default LED blink period to 250ms*3. More...
#define	GET_ROTOR_SLIDER_POSITION(ROTOR_SLIDER_NUMBER)
#define	GET_SENSOR_STATE(SENSOR_NUMBER)
#define	LED_BLINK_PERIOD   3
	LED blink period. More...
#define	LED_FREQ_DIV   3
	frequency divider for LED blinking More...
#define	QT_MAX_DATA   255
	QTouch max data value. More...
#define	QTOUCH_LIB_COMPILER_MASK   0x01
	QTouch library compiler type mask. More...
#define	QTOUCH_LIB_COMPILER_OFFSET   2
	QTouch library compiler type offset: GCC / IAR. More...
#define	QTOUCH_LIB_KEY_ONLY_MASK   0x01
	QTouch library supports keys only mask. More...
#define	QTOUCH_LIB_KEY_ONLY_OFFSET   10
	QTouch library supports keys only offset. More...
#define	QTOUCH_LIB_MAX_CHANNEL_MASK   0x7F
	QTouch library maximum channels mask. More...
#define	QTOUCH_LIB_MAX_CHANNEL_OFFSET   3
	QTouch library maximum channels offset. More...
#define	QTOUCH_LIB_ROTOR_NUM_MASK   0x1F
	QTouch library maximum rotors/sliders mask. More...
#define	QTOUCH_LIB_ROTOR_NUM_OFFSET   11
	QTouch library maximum rotors/sliders offset. More...
#define	QTOUCH_LIB_TPYE_MASK   0x01
	QTouch library type: QTouch / QMatrix. More...

Functions
static void	config_sensors (void)
	Configure the sensors. More...
static void	configure_tc (uint32_t freq)
	Configure Timer Counter 0 to generate an interrupt with the specific frequency. More...
static void	init_system (void)
	initialize pins, watchdog, etc. More...
static void	init_timer_isr (void)
	Configure timer ISR to fire regularly. More...
int	main (void)
	getting-started Application entry point. More...
static void	qt_set_parameters (void)
	This will fill the default threshold values in the configuration data structure.But User can change the values of these parameters. More...
void	SysTick_Handler (void)
	Handler for System Tick interrupt. More...
void	TC0_Handler (void)
	Interrupt handler for TC0 interrupt. More...

Variables
static volatile uint16_t	current_time_ms_touch = 0u
	Current time, set by timer ISR. More...
static volatile uint32_t	led_blink_period = 0
	LED blink period. More...
uint16_t	qt_measurement_period_msec = 25u
	Timer period in msec. More...
uint32_t	qt_shift_data = 0
	Shift data gotten from the QTouch. More...
static volatile uint8_t	time_to_measure_touch = 0u
	Flag set by timer ISR when it's time to measure touch. More...

#define DEFAULT_LED_FREQ   4

Set default LED blink period to 250ms*3.

Referenced by init_system().

#define GET_ROTOR_SLIDER_POSITION

(

ROTOR_SLIDER_NUMBER

)

Value:

qt_measure_data.    \
    qt_touch_status.rotor_slider_values[ROTOR_SLIDER_NUMBER]

Referenced by main().

#define GET_SENSOR_STATE

(

SENSOR_NUMBER

)

Value:

(qt_measure_data.qt_touch_status. \
    sensor_states[(SENSOR_NUMBER / \
    8)] & (1 << (SENSOR_NUMBER % 8)))

#define LED_BLINK_PERIOD   3

LED blink period.

Referenced by TC0_Handler().

#define LED_FREQ_DIV   3

frequency divider for LED blinking

Referenced by main().

#define QT_MAX_DATA   255

QTouch max data value.

Referenced by main().

#define QTOUCH_LIB_COMPILER_MASK   0x01

QTouch library compiler type mask.

#define QTOUCH_LIB_COMPILER_OFFSET   2

QTouch library compiler type offset: GCC / IAR.

#define QTOUCH_LIB_KEY_ONLY_MASK   0x01

QTouch library supports keys only mask.

#define QTOUCH_LIB_KEY_ONLY_OFFSET   10

QTouch library supports keys only offset.

#define QTOUCH_LIB_MAX_CHANNEL_MASK   0x7F

QTouch library maximum channels mask.

#define QTOUCH_LIB_MAX_CHANNEL_OFFSET   3

QTouch library maximum channels offset.

#define QTOUCH_LIB_ROTOR_NUM_MASK   0x1F

QTouch library maximum rotors/sliders mask.

#define QTOUCH_LIB_ROTOR_NUM_OFFSET   11

QTouch library maximum rotors/sliders offset.

#define QTOUCH_LIB_TPYE_MASK   0x01

QTouch library type: QTouch / QMatrix.

static void config_sensors ( void  )

static

Configure the sensors.

References AKS_GROUP_1, HYST_6_25, and RES_8_BIT.

Referenced by main().

static void configure_tc ( uint32_t  freq )

static

Configure Timer Counter 0 to generate an interrupt with the specific frequency.

Parameters

freq	Timer counter frequency.

Configure TC with the frequency and trigger on RC compare.

Start the counter.

References sysclk_get_cpu_hz(), tc_disable_interrupt(), tc_enable_interrupt(), tc_find_mck_divisor(), tc_init(), tc_start(), tc_stop(), and tc_write_rc().

Referenced by init_system(), and main().

static void init_system ( void  )

static

initialize pins, watchdog, etc.

References configure_tc(), DEFAULT_LED_FREQ, gpio_configure_pin, pmc_enable_periph_clk(), sysclk_init(), and wdt_disable().

Referenced by main().

static void init_timer_isr ( void  )

static

Configure timer ISR to fire regularly.

References qt_measurement_period_msec, and sysclk_get_cpu_hz().

Referenced by main().

int main

(

void

)

getting-started Application entry point.

Returns

Unused (ANSI-C compatibility).

References config_sensors(), configure_tc(), current_time_ms_touch, GET_ROTOR_SLIDER_POSITION, init_system(), init_timer_isr(), LED_FREQ_DIV, qt_filter_callback, qt_init_sensing, QT_MAX_DATA, qt_measure_sensors(), qt_reset_sensing(), qt_set_parameters(), qt_shift_data, QTLIB_BURST_AGAIN, and time_to_measure_touch.

static void qt_set_parameters ( void  )

static

This will fill the default threshold values in the configuration data structure.But User can change the values of these parameters.

References DEF_QT_DI, DEF_QT_DRIFT_HOLD_TIME, DEF_QT_MAX_ON_DURATION, DEF_QT_NEG_DRIFT_RATE, DEF_QT_POS_DRIFT_RATE, DEF_QT_POS_RECAL_DELAY, DEF_QT_RECAL_THRESHOLD, qt_config_data, tag_qt_touch_lib_config_data_t::qt_di, tag_qt_touch_lib_config_data_t::qt_drift_hold_time, tag_qt_touch_lib_config_data_t::qt_max_on_duration, tag_qt_touch_lib_config_data_t::qt_neg_drift_rate, tag_qt_touch_lib_config_data_t::qt_pos_drift_rate, tag_qt_touch_lib_config_data_t::qt_pos_recal_delay, and tag_qt_touch_lib_config_data_t::qt_recal_threshold.

Referenced by main().

void SysTick_Handler

(

void

)

Handler for System Tick interrupt.

Process System Tick Event

References current_time_ms_touch, qt_measurement_period_msec, and time_to_measure_touch.

void TC0_Handler

(

void

)

Interrupt handler for TC0 interrupt.

Toggles the state of LEDs.

Toggle LED state.

References gpio_toggle_pin, LED_BLINK_PERIOD, led_blink_period, and tc_get_status().

volatile uint16_t current_time_ms_touch = 0u

static

Current time, set by timer ISR.

volatile uint32_t led_blink_period = 0

static

LED blink period.

Referenced by TC0_Handler().

uint32_t qt_shift_data = 0

Shift data gotten from the QTouch.

Referenced by main().

volatile uint8_t time_to_measure_touch = 0u

static

Flag set by timer ISR when it's time to measure touch.