Mikroelektronika MIKROE-742 데이터 시트

The example changes PWM duty ratio on PB3 and PB7 pins continually. If LED is
connected to PB3 and PB7, you can observe the gradual change of emitted light.

program PWM_Test;

var current_duty : byte;

current_duty1 : byte;

DDRB.B0 := 0;                  // Set PORTB pin 0 as input

DDRB.B1 := 0;                  // Set PORTB pin 1 as input

DDRC.B0 := 0;                  // Set PORTC pin 0 as input
DDRC.B1 := 0;                  // Set PORTC pin 1 as input

current_duty     := 127;         // initial value for current_duty
current_duty1    := 127;         // initial value for current_duty

DDRB.B3 := 1;                   // Set PORTB pin 3 as output pin

for the PWM (according to datasheet)

DDRD.B7 := 1;                    // Set PORTD pin 7 as output pin

for the PWM1 (according to datasheet)

PWM_Init(_PWM_PHASE_CORRECT_MODE, _PWM_PRESCALER_8,

_PWM_NON_INVERTED, 127);

PWM1_Init(_PWM1_PHASE_CORRECT_MODE, _PWM1_PRESCALER_8,

_PWM1_NON_INVERTED, 127);

while TRUE do

if (PINB.0 <> 0) then

// Detect if PORTB pin 0 is pressed

Delay_ms(40);      // Small delay to avoid deboucing effect

Inc(current_duty);                // Increment duty ratio

PWM_Set_Duty(current_duty);        // Set incremented duty

if (PINB.1 <> 0) then

// Detect if PORTB pin 1 is pressed

Delay_ms(40);    // Small delay to avoid deboucing effect

Dec(current_duty);              // Decrement duty ratio

PWM_Set_Duty(current_duty);         // Set decremented

duty ratio

328

- SOFTWARE AND HARDWARE SOLUTIONS FOR EMBEDDED WORLD

CHAPTER 6