{

int compareValue = (SYSCLOCK / (TIMER_PRESCALER_DIV * frequencyHz)) - 1;

//Serial.println(compareValue);

TcCount16* TC = (TcCount16*) TC3;

// Make sure the count is in a proportional position to where it was

// to prevent any jitter or disconnect when changing the compare value.

TC->COUNT.reg = map(TC->COUNT.reg, 0, TC->CC[0].reg, 0, compareValue);

TC->CC[0].reg = compareValue;

//Serial.print("COUNT.reg ");

//Serial.println(TC->COUNT.reg);

//Serial.print("CC[0].reg ");

//Serial.println(TC->CC[0].reg);

while (TC->STATUS.bit.SYNCBUSY == 1);

{

REG_GCLK_CLKCTRL = (uint16_t) (GCLK_CLKCTRL_CLKEN | GCLK_CLKCTRL_GEN_GCLK0 | GCLK_CLKCTRL_ID_TCC2_TC3);

while (GCLK->STATUS.bit.SYNCBUSY == 1); // wait for sync

TcCount16* TC = (TcCount16*) TC3;

TC->CTRLA.reg &= ~TC_CTRLA_ENABLE;

while (TC->STATUS.bit.SYNCBUSY == 1); // wait for sync

// Use the 16-bit timer

TC->CTRLA.reg |= TC_CTRLA_MODE_COUNT16;

while (TC->STATUS.bit.SYNCBUSY == 1); // wait for sync

// Use match mode so that the timer counter resets when the count matches the compare register

TC->CTRLA.reg |= TC_CTRLA_WAVEGEN_MFRQ;

while (TC->STATUS.bit.SYNCBUSY == 1); // wait for sync

// Set prescaler to 1024

//TC->CTRLA.reg |= TC_CTRLA_PRESCALER_DIV1024;

TC->CTRLA.reg |= TC_CTRLA_PRESCALER_DIV64;

while (TC->STATUS.bit.SYNCBUSY == 1); // wait for sync

setTimerFrequency(1000000 / USECPERTICK);

// Enable the compare interrupt

TC->INTENSET.reg = 0;

TC->INTENSET.bit.MC0 = 1;

NVIC_EnableIRQ(TC3_IRQn);

TC->CTRLA.reg |= TC_CTRLA_ENABLE;

while (TC->STATUS.bit.SYNCBUSY == 1); // wait for sync

{

// Interrupt Service Routine - Fires every 50uS

//Serial.println("Starting timer");

startTimer();

//Serial.println("Started timer");

// Initialize state machine variables

irparams.rcvstate = STATE_IDLE;

irparams.rawlen = 0;

// Set pin modes

pinMode(irparams.recvpin, INPUT);

{

TcCount16* TC = (TcCount16*) TC3;

// If this interrupt is due to the compare register matching the timer count

// we toggle the LED.

if (TC->INTFLAG.bit.MC0 == 1) {

TC->INTFLAG.bit.MC0 = 1;

irs();

}