//! [callback_funcs]
void tc_callback_to_change_duty_cycle(
struct tc_module *const module_inst)
{
static uint16_t i = 0;
i += 128;
tc_set_compare_value(module_inst, TC_COMPARE_CAPTURE_CHANNEL_0, i + 1);
}
/*!
* @brief Implements a delay of the length of the argument in
econds
*
* @param[in] NULL
*
* @param[out] NULL
*
* @return NULL
*
*/
void tc4_wait_for_msec (uint32_t msec)
{
/* Set the compare value */
tc_set_compare_value(&tc4_instance, TC_COMPARE_CAPTURE_CHANNEL_0, (msec *500));
/* start counting */
tc_start_counter(&tc4_instance);
/* delay until required time is elapsed */
while (!tc4_callback_flag);
/* stop the counter */
tc_stop_counter(&tc4_instance);
/* reset the interrupt flag */
tc4_callback_flag = false;
}
void Adafruit_ZeroTimer::setCompare(uint8_t channum, uint32_t compare) {
if (channum > 1) return;
// set the configuration
if (_countersize == TC_COUNTER_SIZE_8BIT) {
config_tc.counter_8_bit.compare_capture_channel[channum] = compare;
}
else if (_countersize == TC_COUNTER_SIZE_16BIT) {
config_tc.counter_16_bit.compare_capture_channel[channum] = compare;
}
else if (_countersize == TC_COUNTER_SIZE_32BIT) {
config_tc.counter_32_bit.compare_capture_channel[channum] = compare;
}
// set it live
tc_set_compare_value(&tc_instance, (tc_compare_capture_channel)channum, compare);
}
void us_ticker_set_interrupt(timestamp_t timestamp)
{
uint32_t cur_time;
int32_t delta;
cur_time = us_ticker_read();
delta = (int32_t)((uint32_t)timestamp - cur_time);
if (delta < 0) {
/* Event already occurred in past */
us_ticker_irq_handler();
return;
}
NVIC_DisableIRQ(TICKER_COUNTER_IRQn);
NVIC_SetVector(TICKER_COUNTER_IRQn, (uint32_t)TICKER_COUNTER_Handlr);
/* Enable the callback */
tc_enable_callback(&us_ticker_module, TC_CALLBACK_CC_CHANNEL0);
tc_set_compare_value(&us_ticker_module, TC_COMPARE_CAPTURE_CHANNEL_0, (uint32_t)timestamp);
NVIC_EnableIRQ(TICKER_COUNTER_IRQn);
}
/*! \brief to load compare value in channel compare register
*/
void tmr_write_cmpreg(uint16_t compare_value)
{
tc_set_compare_value(&module_inst, TC_COMPARE_CAPTURE_CHANNEL_0,
(uint32_t)compare_value);
}
/* Timer 0 Initialization */
void timer_init(void)
{
struct tc_config conf_tc;
struct tc_events conf_tc_events = {.generate_event_on_compare_channel[0] = 1};
tc_get_config_defaults(&conf_tc);
conf_tc.clock_source = GCLK_GENERATOR_0;
conf_tc.wave_generation = TC_WAVE_GENERATION_MATCH_FREQ;
conf_tc.counter_16_bit.compare_capture_channel[0] = 0xFFFF;
tc_init(&tc_inst, TC0, &conf_tc);
tc_enable_events(&tc_inst, &conf_tc_events);
tc_enable(&tc_inst);
tc_stop_counter(&tc_inst);
/* Enable TC0 match/capture channel 0 interrupt */
TC0->COUNT16.INTENSET.bit.MC0 = 1;
/* Enable TC0 module interrupt */
NVIC_EnableIRQ(TC0_IRQn);
}
/* DAC Initialization */
void dac_initialize(void)
{
struct dac_config conf_dac;
struct dac_events conf_dac_events = {.on_event_start_conversion = 1};
dac_get_config_defaults(&conf_dac);
conf_dac.clock_source = GCLK_GENERATOR_3;
conf_dac.reference = DAC_REFERENCE_INT1V;
dac_init(&dac_inst, DAC, &conf_dac);
dac_enable_events(&dac_inst, &conf_dac_events);
dac_enable(&dac_inst);
}
/* Event System Initialization */
void evsys_init(void)
{
struct events_resource conf_event_resource;
struct events_config conf_event;
events_get_config_defaults(&conf_event);
conf_event.edge_detect = EVENTS_EDGE_DETECT_NONE;
conf_event.path = EVENTS_PATH_ASYNCHRONOUS;
conf_event.generator = EVSYS_ID_GEN_TC0_MCX_0;
events_allocate(&conf_event_resource, &conf_event);
events_attach_user(&conf_event_resource, EVSYS_ID_USER_DAC_START);
}
/* Initialize the selected waveform buffer with output data */
void buffer_init(void)
{
#if WAVE_MODE==SINE_WAVE
for (i = 0; i < DEGREES_PER_CYCLE; i++) {
sine_wave_buf[i] = (uint16_t)(500 + (500*sin((double)i*DEGREE)));
}
#elif WAVE_MODE==SAW_TOOTH_WAVE
for (i = 0; i < 256; i++) {
sawtooth_wave_buf[i] = i*4;
}
#elif WAVE_MODE==TRIANGLE_WAVE
for (i = 0; i < 128; i++) {
triangle_wave_buf[i] = i*8;
}
for (i = 128; i < 256; i++) {
triangle_wave_buf[i] = 1023 - (i*8);
}
#endif
}
/* Main function */
int main(void)
{
system_init();
timer_init();
dac_initialize();
evsys_init();
buffer_init();
/* Set the TC0 compare value corresponding to specified frequency */
#if WAVE_MODE==SINE_WAVE
tc_set_compare_value(&tc_inst, 0, \
system_gclk_gen_get_hz(GCLK_GENERATOR_0)/(FREQUENCY*360));
#else
tc_set_compare_value(&tc_inst, 0, \
system_gclk_gen_get_hz(GCLK_GENERATOR_0)/(FREQUENCY*256));
#endif
/* Start TC0 timer */
tc_start_counter(&tc_inst);
/* Enable global interrupt */
system_interrupt_enable_global();
while (true) {
}
}
