// Measure the offset from the rising edge of the ZCD to the true zero crossing.
// An oscilloscope trace of the ZCD pcb, used in the project can be found here:
// http://electronics.stackexchange.com/questions/201605/automatic-calibration-of-a-zero-cross-detector-latency
// It is evident, that the pulse is wide, but centered around the ZC.
// Therefore, we measure its width and divide it by two to get the offset from the rising edge to the true ZC.
time_t zcd_calibrate(void)
{
// Restore interrupt status after exit.
// Enable all interrupts here, because there were glitches when altering TIMSK1 form an ISR.
char sreg = SREG;
sei();
TIMSK1 = (1<<ICIE1); // Enable edge interrupts.
// Wait for rising edge of the zcd pulse.
g_calibration_mode = true;
start_timer1_capture_rising();
while(!g_event_captured);
g_event_captured = false;
ATOMIC{ TCNT1 = 0; } // Clear timer1.
// Measure pulse width.
ATOMIC{ start_timer1_capture_falling(); }
while(!g_event_captured);
volatile time_t count;
ATOMIC{ count = ICR1; } // Width of the zcd pulse, in CPU cycles.
stop_timer1();
// Estimate offset from measured to real zc.
time_t rising_to_zc = count / 2; // In CPU cycles.
SREG = sreg;
return rising_to_zc;
}
/**
* \fn void note(char temps, int note)
* \brief Permet de jouer une note pendant un certain temps
* \param [IN] temps est la duree pendant laquelle on souhaite jouer la note
- temps ne doit pas depasser la valeur 11 ( 2^8 / 5760 )
[IN] note est la fréquence d'OCR0A que l'on souhaite jouer
*/
void note(char temps, int note)
{
start_timer0(note);
start_timer1(temps * 5760); // 100 ms
wait_OCR1A_timer1();
stop_timer1();
stop_timer0();
}
uint8_t process_ARE_frame(uint8_t status_code)
{
uint8_t ack_needed;
uint8_t data_size=0;
uint8_t command;
// LEDs_ToggleLEDs(LED0); // indicate correct frame
command=(uint8_t)ARE_frame.request_code;
CIM_frame.cim_feature=ARE_frame.cim_feature;
CIM_frame.serial_number=ARE_frame.serial_number;
CIM_frame.reply_code=(((uint16_t)status_code)<<8) + command;
data_size=(uint8_t)ARE_frame.data_size;
ack_needed=1;
// if ((status_code & (CIM_ERROR_INVALID_ARE_VERSION | CIM_ERROR_CRC_MISMATCH)) == 0)
if ((status_code & CIM_ERROR_INVALID_ARE_VERSION) == 0)
{
// UART_Print(" feature "); UART_Putchar(command);
// no serious packet error
switch (command) { // process requested command
case CMD_REQUEST_FEATURELIST:
if (data_size==0) {
reply_FeatureList(); // reply requested feature list
ack_needed=0;
} else status_code |= CIM_ERROR_INVALID_FEATURE;
break;
case CMD_REQUEST_RESET_CIM:
if (data_size!=0) status_code |= CIM_ERROR_INVALID_FEATURE;
break;
case CMD_REQUEST_START_CIM:
if (data_size==0) {
cli();
init_CIM_frame();
setupHardware();
start_timer1();
sei();
} else status_code |= CIM_ERROR_INVALID_FEATURE;
break;
case CMD_REQUEST_STOP_CIM:
if (data_size==0) {
first_packet=1; // reset first frame indicator etc.
stop_timer1();
} else status_code |= CIM_ERROR_INVALID_FEATURE;
break;
case CMD_REQUEST_READ_FEATURE: // read feature from CIM
switch (ARE_frame.cim_feature) {
case TEENSY_CIM_FEATURE_UNIQUENUMBER: // read unique serial number
if (data_size==0) {
reply_UniqueNumber();
ack_needed=0;
} else status_code |= CIM_ERROR_INVALID_FEATURE;
break;
default: // not a valid read feature;
status_code |= CIM_ERROR_INVALID_FEATURE;
}
break;
case CMD_REQUEST_WRITE_FEATURE: // write feature to CIM
switch (ARE_frame.cim_feature) { // which feature address ?
case TEENSY_CIM_FEATURE_MODE_SELECTION:
if (data_size==2) {
cli();
selection = (uint16_t)ARE_frame.data[0];
selection += ((uint16_t)ARE_frame.data[1])<<8;
sei();
}
break;
case TEENSY_CIM_FEATURE_SET_THRESHOLD:
if (data_size==2) {
cli();
threshold = (uint16_t)ARE_frame.data[0];
threshold += ((uint16_t)ARE_frame.data[1])<<8;
sei();
}
break;
/*case TEENSY_CIM_FEATURE_SET_ADCPERIOD:
if (data_size==2) {
cli();
ADC_updatetime= (uint16_t)ARE_frame.data[0];
ADC_updatetime+= ((uint16_t)ARE_frame.data[1])<<8;
sei();
}
break;*/
default: // not a valid write feature;
status_code |= CIM_ERROR_INVALID_FEATURE;
}
}
}
if (status_code & CIM_ERROR_INVALID_FEATURE) { // invalid data size or feature
// LEDs_ToggleLEDs(LED5); // indicate wrong feature
// UART_Print(" invalid data size or no feature ");
}
if (ack_needed) {
reply_Acknowledge();
}
return(1);
}
