/**
* \brief Handler for ADC interrupt.
*/
void ADC_Handler(void)
{
uint32_t low_threshold;
uint32_t high_threshold;
uint32_t status = adc_get_status(ADC);
/* Read the status to ack the IT */
if ((status & ADC_ISR_COMPE) == ADC_ISR_COMPE) {
/* Get the potentiometer initial value */
pontentiometer_value = adc_get_channel_value( ADC,
ADC_CHANNEL_POTENTIOMETER );
/* Set Window threshold according to the initial values */
low_threshold = pontentiometer_value -
(NB_INTERVALS * (0x1000 / 256));
if (low_threshold > 0xf0000000) {
low_threshold = 0;
}
high_threshold = pontentiometer_value +
(NB_INTERVALS * (0x1000 / 256));
if (high_threshold >= 0x1000) {
high_threshold = 0x1000 - 1;
}
/* Normalize the value 0 -> 255 */
pontentiometer_value
= pontentiometer_value*100 + 1;
ppt_delay_clapse_counter = 0;
/* Setup Threshold*/
adc_set_comparison_window( ADC, low_threshold,
high_threshold);
/* Compare mode, in the window. */
adc_enable_interrupt(ADC, ADC_IER_COMPE);
}
if (status & ADC_ISR_ENDRX) {
/* Start next buffer */
ADC->ADC_RNPR = (uint32_t)
frame_buffer[(adc_buf_ndx + 2) % AUDIO_NB_BUFFER];
ADC->ADC_RNCR = AUDIO_FRAME_SIZE;
adc_buf_ndx = (adc_buf_ndx + 1) % AUDIO_NB_BUFFER;
adc_nb_samples += AUDIO_FRAME_SIZE;
}
}
/**
* \brief Example entry point.
*
* Initialize ADC to 12-bit, enable channel "ADC_CHANNEL_POTENTIOMETER", then
* enable hardware trigger with TIOA0 every second. Finally, start conversion.
*
* \return Unused (ANSI-C compatibility).
*/
int main(void)
{
uint8_t c_choice;
int16_t s_adc_value;
int16_t s_threshold = 0;
/* Initialize the SAM system. */
sysclk_init();
board_init();
configure_console();
/* Output example information. */
puts(STRING_HEADER);
/* Initialize threshold. */
gs_us_low_threshold = 0x0;
gs_us_high_threshold = MAX_DIGITAL;
/* Enable peripheral clock. */
pmc_enable_periph_clk(ID_ADC);
/* Initialize ADC. */
/* startup = 10: 640 periods of ADCClock
* for prescale = 4
* prescale: ADCClock = MCK / ( (PRESCAL+1) * 2 ) => 64MHz / ((4+1)*2) = 6.4MHz
* ADC clock = 6.4 MHz
*/
adc_init(ADC, sysclk_get_cpu_hz(), 6400000, 10);
#if SAM3S || SAM3XA || SAM4S
adc_configure_timing(ADC, 0, ADC_SETTLING_TIME_3, 1);
#elif SAM3N
adc_configure_timing(ADC, 0);
#endif
adc_check(ADC, sysclk_get_cpu_hz());
/* Hardware trigger TIOA0. */
adc_configure_trigger(ADC, ADC_TRIG_TIO_CH_0, 0);
/* Enable channels for x,y and z. */
adc_enable_channel(ADC, ADC_CHANNEL_POTENTIOMETER);
/* Configure TC. */
configure_tc0();
/* Channel 5 has to be compared. */
adc_set_comparison_channel(ADC, ADC_CHANNEL_POTENTIOMETER);
/* Compare mode, in the window. */
adc_set_comparison_mode(ADC, ADC_EMR_CMPMODE_IN);
/* Set up Threshold. */
adc_set_comparison_window(ADC, gs_us_high_threshold, gs_us_low_threshold);
/* Enable ADC interrupt. */
NVIC_EnableIRQ(ADC_IRQn);
/* Start TC0 and hardware trigger. */
tc_start(TC0, 0);
/* Display main menu. */
display_menu();
while (1) {
while (uart_read(CONSOLE_UART, &c_choice)) {
}
printf("%c\r\n", c_choice);
switch (c_choice) {
case '0':
s_adc_value = adc_get_channel_value(ADC,
ADC_CHANNEL_POTENTIOMETER);
printf("-I- Current voltage is %d mv, %d%% of ADVREF\n\r",
(s_adc_value * VOLT_REF / MAX_DIGITAL), (s_adc_value * 100 / MAX_DIGITAL));
break;
case '1':
puts("Low threshold is set to(mv):");
s_threshold = get_voltage();
puts("\r");
if (s_threshold >= 0) {
s_adc_value = s_threshold * MAX_DIGITAL /
VOLT_REF;
adc_set_comparison_window(ADC, s_adc_value,
gs_us_high_threshold);
/* Renew low threshold. */
gs_us_low_threshold = s_adc_value;
float f_low_threshold = (float)gs_us_low_threshold * VOLT_REF / MAX_DIGITAL;
uint32_t ul_low_threshold = f_to_int(f_low_threshold);
printf("Setting low threshold to %u mv (reg value to 0x%x ~%d%%)\n\r",
ul_low_threshold,
gs_us_low_threshold,
gs_us_low_threshold * 100 / MAX_DIGITAL);
}
break;
case '2':
puts("High threshold is set to(mv):");
s_threshold = get_voltage();
puts("\r");
if (s_threshold >= 0) {
s_adc_value = s_threshold * MAX_DIGITAL /
VOLT_REF;
adc_set_comparison_window(ADC, gs_us_low_threshold,
s_adc_value);
/* Renew high threshold. */
gs_us_high_threshold = s_adc_value;
float f_high_threshold = (float)gs_us_high_threshold * VOLT_REF / MAX_DIGITAL;
uint32_t ul_high_threshold = f_to_int(f_high_threshold);
printf("Setting high threshold to %u mv (reg value to 0x%x ~%d%%)\n\r",
ul_high_threshold,
gs_us_high_threshold,
gs_us_high_threshold * 100 / MAX_DIGITAL);
}
break;
case '3':
puts("-a. Below low threshold.\n\r"
"-b. Above high threshold.\n\r"
"-c. In the comparison window.\n\r"
"-d. Out of the comparison window.\n\r"
"-q. Quit the setting.\r");
c_choice = get_comparison_mode();
adc_set_comparison_mode(ADC, c_choice);
printf("Comparison mode is %c.\n\r", 'a' + c_choice);
break;
case 'm':
case 'M':
display_menu();
break;
case 'i':
case 'I':
display_info();
break;
case 's':
case 'S':
enter_asleep();
break;
}
puts("Press \'m\' or \'M\' to display the main menu again!\r");
}
}
/**
* \brief Turn on/off ADC module.
*
* \param on True to start ADC, false to turn off.
*/
static void demo_start_adc(bool on)
{
uint32_t low_threshold, high_threshold;
if (on == true) {
/* Check if already enabled */
if (demo_adc_on) {
return;
}
demo_config_adc();
/* Start TC0 and hardware trigger. */
tc_start(TC0, 1);
/* Get the potentiometer initial value */
pontentiometer_value = adc_get_channel_value(ADC,
ADC_CHANNEL_POTENTIOMETER);
/* Set Window threshold according to the initial values */
low_threshold = pontentiometer_value -
(NB_INTERVALS * (0x1000 / 256));
if (low_threshold > 0xf000000) {
low_threshold = 0;
}
high_threshold = pontentiometer_value +
(NB_INTERVALS * (0x1000 / 256));
if (high_threshold >= 0x1000) {
high_threshold = 0x1000 - 1;
}
pontentiometer_value
= pontentiometer_value*100 + 1;
/* Channel 5 has to be compared. */
adc_set_comparison_channel(ADC, ADC_CHANNEL_POTENTIOMETER);
/* Compare mode, out the window. */
adc_set_comparison_mode(ADC, ADC_EMR_CMPMODE_OUT);
/* Set up Threshold. */
adc_set_comparison_window(ADC, low_threshold,
high_threshold);
/* Enable ADC interrupt. */
NVIC_EnableIRQ(ADC_IRQn);
/* Enable Compare Interrupt. */
adc_enable_interrupt(ADC, ADC_IER_COMPE);
/* Set adc on flag */
demo_adc_on = 1;
/* Reset clapse time */
ppt_delay_clapse_counter = 0;
} else {
tc_stop(TC0, 1);
/* Enable ADC interrupt. */
NVIC_DisableIRQ(ADC_IRQn);
/* Enable Compare Interrupt. */
adc_disable_interrupt(ADC, ADC_IDR_COMPE);
/* Set adc off flag */
demo_adc_on = 0;
}
}