]> www.fi.muni.cz Git - bike-lights.git/blobdiff - firmware/pwm.c
firmware: move PWM_MAX to lights.h
[bike-lights.git] / firmware / pwm.c
index 0c4f3d081a5b78ddbc9f2493255a17b0da6496bf..201770f8152f440fe7ef21a219c336fb9f382b5f 100644 (file)
@@ -15,28 +15,32 @@ void init_pwm()
                ;
        PLLCSR |= _BV(PCKE);
 
-       TCCR1C = _BV(COM1D0) | _BV(COM1D1) | _BV(PWM1D);
-       TCCR1A = _BV(COM1A0) | _BV(COM1A1) | _BV(COM1B0) | _BV(COM1B1) | _BV(PWM1A) | _BV(PWM1B);
-       TCCR1B = _BV(7)                         // PWM1X: PWM inversion mode
-               | _BV(CS10)                     // no clock prescaling
-               ;
-       TC1H = 0x01;
-       OCR1C = 0xFF;                           // TOP value
+       // PWM channel D is inverted, ...
+       TCCR1C = _BV(COM1D1) | _BV(COM1D0) | _BV(PWM1D);
+       // PWM channels A and B are not
+       TCCR1A = _BV(COM1A1) | _BV(COM1B1) | _BV(PWM1A) | _BV(PWM1B);
+       TCCR1D = 0;
+       TCCR1B = _BV(CS10);                     // no clock prescaling
+
+       TC1H = PWM_MAX >> 8;
+       OCR1C = PWM_MAX & 0xFF;                         // TOP value
+
+       TC1H = PWM_MAX >> 8;            // PWM3 is inverted
+       OCR1D = PWM_MAX & 0xFF;
 
        TC1H = 0x00;
-       OCR1D = OCR1B = OCR1A = 0;              // initial stride is 0
+       OCR1B = OCR1A = 0;              // initial stride is 0
 
        DDRB  &= ~(_BV( PB1 ) | _BV( PB3 ) | _BV( PB5 )); // tristate it
        PORTB &= ~(_BV( PB1 ) | _BV( PB3 ) | _BV( PB5 )); // set to zero
 }
 
-void pwm_on(unsigned char n)
+void susp_pwm()
 {
-       switch (n) {
-       case 0: DDRB |= _BV(PB1); break;
-       case 1: DDRB |= _BV(PB3); break;
-       case 2: DDRB |= _BV(PB5); break;
-       }
+       DDRB &= ~(_BV( PB1 ) | _BV( PB3 ) | _BV( PB5 ));
+       TCCR1D = TCCR1C = TCCR1B = TCCR1A = 0;
+       TIMSK = 0;
+       TIFR = 0;
 }
 
 void pwm_off(unsigned char n)
@@ -48,13 +52,35 @@ void pwm_off(unsigned char n)
        }
 }
 
-void pwm_set(unsigned char n, unsigned char stride)
+void pwm_set(unsigned char n, uint16_t stride)
 {
-       TC1H = 0x00;
+       unsigned char hi, lo;
+
+       if (stride > PWM_MAX)
+               stride = PWM_MAX;
+
+       if (n == 2)
+               stride = PWM_MAX - stride;
+
+       hi = stride >> 8;
+       lo = stride & 0xFF;
+
        switch (n) {
-       case 0: OCR1A = stride; break;
-       case 1: OCR1B = stride; break;
-       case 2: OCR1D = stride; break;
+       case 0:
+               TC1H = hi;
+               OCR1A = lo;
+               DDRB |= _BV(PB1);
+               break;
+       case 1:
+               TC1H = hi;
+               OCR1B = lo;
+               DDRB |= _BV(PB3);
+               break;
+       case 2:
+               TC1H = hi;
+               OCR1D = lo;
+               DDRB |= _BV(PB5);
+               break;
        }
 }