// This function initializes the PWMs
void Init_PWM( void )
{
// Set PWM outputs
MOTOR_OUTPUT.DIRSET = 0x03; // PD0/PD1 set as outputs
// Configure timer
TC0_ConfigWGM(&MOTOR_TIMER, TC_WGMODE_SS_gc);
TC0_EnableCCChannels(&MOTOR_TIMER, TC0_CCAEN_bm|TC0_CCBEN_bm);
TC_SetCompareA(&MOTOR_TIMER, 0);
TC_SetCompareB(&MOTOR_TIMER, 0);
TC_SetPeriod(&MOTOR_TIMER, MAX_PWM);
TC0_ConfigClockSource(&MOTOR_TIMER, TC_CLKSEL_DIV1_gc); // 32MHz
}
int main( void )
{
/* To change the duty cycle for the PWM for the LED control, use a variable to increase/decrease the
* CCx registers once for each period */
int16_t pwm_delta = 300;
// Add code to select a Single Slope PWM as Waveform Generation mode.
// This is done by setting the WGM bits,in the CTRLB register for the TC.
/* Add code to enable the CC channels we wish to use. Each channel must be separately enabled
* by setting the corresponding CCxEN bits in the CTRLB register for the TC.
* Code for enabling CCA is already added, but add code to enable CCB, CCC and CCD */
TCE0.CTRLB |= TC0_CCAEN_bm;
//Insert code to enable CC for the other channels, B, C and D.
/* The corresponding port pins MUST be ouput for the Waveform to be visible
* on the pin. For TCE0 the corresponding port is PORTE, and pin 0 to 3 for
* CC channel A to D */
PORTE.DIRSET = 0x0F;
/* Note how the inverted signal is always controlled from the Port pin configuration in XMEGA
* This can be used with all other peripherals connected to the pin to have inverted output.
* Below is example code on how you can set inverted ouput on a pin using the Pin Control Register*/
//PORTE.PIN0CTRL &= ~PORT_INVEN_bm;
/* Set a compare value for each compare channel, just as in task2.
* The compare value decide the PWM duty cycle for the waveform.
*
* Code for CC channel A is added, add code for channel B, C, and D
* with the compare value 3000 */
TC_SetCompareA(&TCE0, 3000);
//Insert function calls to set the other compare values
/* Using the TC_driver we set the Period and
* start the timer with no prescaling */
TC_SetPeriod(&TCE0, 60000);
TC0_ConfigClockSource(&TCE0, TC_CLKSEL_DIV1_gc);
while(1)
{
/* The code check if the overflow flag is set,
* if so it clears the flag and sets a new duty cycle for all
* CC channels */
/* Check if overflow flag (OVFIF) is set,
* clear flag and set a new duty cycle
*/
if(TC_GetOverflowFlag(&TCE0) != 0)
{
TC_ClearOverflowFlag(&TCE0); //Clear the IF by writing a logical 1 to the flag
if(TCE0.CCA >= 59000)
{ //Some "random" values above 0 and below TOP is selected
pwm_delta = -300; //for the PWM changes, and make the LED look ok.
}
else if(TCE0.CCA <= 5000)
{
pwm_delta = +300;
}
TCE0.CCABUF += pwm_delta; //Change the compare value to change duty cycle
TCE0.CCBBUF += pwm_delta;
TCE0.CCCBUF += pwm_delta;
TCE0.CCDBUF += pwm_delta;
}
}
}
