/*
This example shows how to configure TCC0 for basic timer operation.
The timer will run at the main clock frequency (32MHz) so we need
to do a bit of math to derive the number of clock cycles to arrive
at the desired microsecond time out.
*/
void startTimer(uint16_t microseconds)
{
uint32_t cycles;
// There are 31.25 nano seconds per clock cycle.
// So we multiply the micro seconds by the clock period to determine
// the number of clock cycles to achieve the microsecond timeout.
// That number of cycles becomes our TOP value.
// We will use 32 nano seconds to preclude floating point arithmetic.
cycles = 32*microseconds;
// Set period/TOP value.
TCC0.CCA = cycles;
// Set the CNT to 0.
TC_SetCount(&TCC0, 0);
/* Enable Input "Capture or Compare" channel A. */
TC0_EnableCCChannels( &TCC0, TC0_CCAEN_bm );
// Select clock source and start the timer.
TC0_ConfigClockSource( &TCC0, TC_CLKSEL_DIV1_gc );
// Enable CCA interrupt.
TC0_SetCCAIntLevel( &TCC0, TC_CCAINTLVL_LO_gc );
PMIC.CTRL |= PMIC_LOLVLEN_bm;
}
void battery_init()
{
PORTD.DIRSET = PIN4_bm | PIN5_bm | PIN6_bm; // battery level indicator
PORTD.OUT = 0x00;
PORTC.DIRSET = PIN7_bm; // signal to stop the boost converters
PORTC.OUTSET = PIN7_bm; // start with the converters stopped to avoid power
// surges on the battery. When the voltage recovers
// the converters will be enabled again
PORTC.DIRCLR = PIN6_bm; // input V_USB_CHG
PORTE.DIRCLR = PIN3_bm; // input CHG_STAT
// update once for each second (1Hz)
TC_SetPeriod(&TCE0, 31250);
TC0_ConfigClockSource(&TCE0, TC_CLKSEL_DIV256_gc);
TC0_ConfigWGM(&TCE0, TC_WGMODE_NORMAL_gc);
TC0_EnableCCChannels(&TCE0, TC0_CCAEN_bm);
TC0_SetCCAIntLevel(&TCE0, TC_CCAINTLVL_LO_gc);
}
