// Calculate & set any offsets to account for execution times.
//
// Args:
// hz: The frequency to calibrate at >= 1000Hz. Default is 38000Hz.
//
// Status: ALPHA / Untested.
//
// NOTE:
// This will generate an 65535us mark() IR LED signal.
// This only needs to be called once, if at all.
void IRsend::calibrate(uint16_t hz) {
if (hz < 1000) // Were we given kHz? Supports the old call usage.
hz *= 1000;
periodOffset = 0; // Turn off any existing offset while we calibrate.
enableIROut(hz);
IRtimer usecTimer = IRtimer(); // Start a timer *just* before we do the call.
uint16_t pulses = mark(UINT16_MAX); // Generate a PWM of 65,535 us. (Max.)
uint32_t timeTaken = usecTimer.elapsed(); // Record the time it took.
// While it shouldn't be neccesary, assume at least 1 pulse, to avoid a
// divide by 0 situation.
pulses = std::max(pulses, (uint16_t) 1U);
uint32_t calcPeriod = calcUSecPeriod(hz); // e.g. @38kHz it should be 26us.
// Assuming 38kHz for the example calculations:
// In a 65535us pulse, we should have 2520.5769 pulses @ 26us periods.
// e.g. 65535.0us / 26us = 2520.5769
// This should have caused approx 2520 loops through the main loop in mark().
// The average over that many interations should give us a reasonable
// approximation at what offset we need to use to account for instruction
// execution times.
//
// Calculate the actual period from the actual time & the actual pulses
// generated.
double_t actualPeriod = (double_t) timeTaken / (double_t) pulses;
// Store the difference between the actual time per period vs. calculated.
periodOffset = (int8_t) ((double_t) calcPeriod - actualPeriod);
}
// Set the output frequency modulation and duty cycle.
//
// Args:
// freq: The freq we want to modulate at. Assumes < 1000 means kHz else Hz.
// duty: Percentage duty cycle of the LED. e.g. 25 = 25% = 1/4 on, 3/4 off.
//
// Note:
// Integer timing functions & math mean we can't do fractions of
// microseconds timing. Thus minor changes to the freq & duty values may have
// limited effect. You've been warned.
void IRsend::enableIROut(uint32_t freq, uint8_t duty) {
// Can't have more than 100% duty cycle.
duty = std::min(duty, (uint8_t) 100);
if (freq < 1000) // Were we given kHz? Supports the old call usage.
freq *= 1000;
uint32_t period = calcUSecPeriod(freq);
// Nr. of uSeconds the LED will be on per pulse.
onTimePeriod = (period * duty) / 100;
// Nr. of uSeconds the LED will be off per pulse.
offTimePeriod = period - onTimePeriod;
}
// Send a Pronto Code formatted message.
//
// Args:
// data: An array of uint16_t containing the pronto codes.
// len: Nr. of entries in the data[] array.
// repeat: Nr. of times to repeat the message.
//
// Status: ALPHA / Not tested in the real world.
//
// Note:
// Pronto codes are typically represented in hexadecimal.
// You will need to convert the code to an array of integers, and calculate
// it's length.
// e.g.
// A Sony 20 bit DVD remote command.
// "0000 0067 0000 0015 0060 0018 0018 0018 0030 0018 0030 0018 0030 0018
// 0018 0018 0030 0018 0018 0018 0018 0018 0030 0018 0018 0018 0030 0018
// 0030 0018 0030 0018 0018 0018 0018 0018 0030 0018 0018 0018 0018 0018
// 0030 0018 0018 03f6"
//
// converts to:
//
// uint16_t prontoCode[46] = {
// 0x0000, 0x0067, 0x0000, 0x0015,
// 0x0060, 0x0018, 0x0018, 0x0018, 0x0030, 0x0018, 0x0030, 0x0018,
// 0x0030, 0x0018, 0x0018, 0x0018, 0x0030, 0x0018, 0x0018, 0x0018,
// 0x0018, 0x0018, 0x0030, 0x0018, 0x0018, 0x0018, 0x0030, 0x0018,
// 0x0030, 0x0018, 0x0030, 0x0018, 0x0018, 0x0018, 0x0018, 0x0018,
// 0x0030, 0x0018, 0x0018, 0x0018, 0x0018, 0x0018, 0x0030, 0x0018,
// 0x0018, 0x03f6};
// // Send the Pronto(Sony) code. Repeat twice as Sony's require that.
// sendPronto(prontoCode, 46, SONY_MIN_REPEAT);
//
// Ref:
// http://www.etcwiki.org/wiki/Pronto_Infrared_Format
// http://www.remotecentral.com/features/irdisp2.htm
void IRsend::sendPronto(uint16_t data[], uint16_t len, uint16_t repeat) {
// Check we have enough data to work out what to send.
if (len < PRONTO_MIN_LENGTH) return;
// We only know how to deal with 'raw' pronto codes types. Reject all others.
if (data[PRONTO_TYPE_OFFSET] != 0) return;
// Pronto frequency is in Hz.
uint16_t hz = (uint16_t) (1000000U / (data[PRONTO_FREQ_OFFSET] *
PRONTO_FREQ_FACTOR));
enableIROut(hz);
// Grab the length of the two sequences.
uint16_t seq_1_len = data[PRONTO_SEQ_1_LEN_OFFSET] * 2;
uint16_t seq_2_len = data[PRONTO_SEQ_2_LEN_OFFSET] * 2;
// Calculate where each sequence starts in the buffer.
uint16_t seq_1_start = PRONTO_DATA_OFFSET;
uint16_t seq_2_start = PRONTO_DATA_OFFSET + seq_1_len;
uint32_t periodic_time = calcUSecPeriod(hz, false);
// Normal (1st sequence) case.
// Is there a first (normal) sequence to send?
if (seq_1_len > 0) {
// Check we have enough data to send the complete first sequence.
if (seq_1_len + seq_1_start > len) return;
// Send the contents of the 1st sequence.
for (uint16_t i = seq_1_start; i < seq_1_start + seq_1_len; i += 2) {
mark(data[i] * periodic_time);
space(data[i + 1] * periodic_time);
}
} else {
// There was no first sequence to send, it is implied that we have to send
// the 2nd/repeat sequence an additional time. i.e. At least once.
repeat++;
}
// Repeat (2nd sequence) case.
// Is there a second (repeat) sequence to be sent?
if (seq_2_len > 0) {
// Check we have enough data to send the complete second sequence.
if (seq_2_len + seq_2_start > len) return;
// Send the contents of the 2nd sequence.
for (uint16_t r = 0; r < repeat; r++)
for (uint16_t i = seq_2_start; i < seq_2_start + seq_2_len; i += 2) {
mark(data[i] * periodic_time);
space(data[i + 1] * periodic_time);
}
}
}
// Set the output frequency modulation and duty cycle.
//
// Args:
// freq: The freq we want to modulate at. Assumes < 1000 means kHz else Hz.
// duty: Percentage duty cycle of the LED. e.g. 25 = 25% = 1/4 on, 3/4 off.
// This is ignored if modulation is disabled at object instantiation.
//
// Note:
// Integer timing functions & math mean we can't do fractions of
// microseconds timing. Thus minor changes to the freq & duty values may have
// limited effect. You've been warned.
void IRsend::enableIROut(uint32_t freq, uint8_t duty) {
// Set the duty cycle to use if we want freq. modulation.
if (modulation) {
_dutycycle = std::min(duty, (uint8_t) DUTY_MAX);
} else {
_dutycycle = DUTY_MAX;
}
if (freq < 1000) // Were we given kHz? Supports the old call usage.
freq *= 1000;
uint32_t period = calcUSecPeriod(freq);
// Nr. of uSeconds the LED will be on per pulse.
onTimePeriod = (period * _dutycycle) / DUTY_MAX;
// Nr. of uSeconds the LED will be off per pulse.
offTimePeriod = period - onTimePeriod;
}
