X-Git-Url: https://www.fi.muni.cz/~kas/git//home/kas/public_html/git/?p=bike-lights.git;a=blobdiff_plain;f=firmware%2Fpwm.c;fp=firmware%2Fpwm.c;h=10c03ba700677a9141ad165ef761357a64f0d3d1;hp=4eb2f83183a1ee411176b58815180afe12d786d0;hb=38a3c5783c24a17e6cf1fbf0af40ae1dec805419;hpb=50b66ac17ddb7c5cf2105959905bdb3ca183a978

diff --git a/firmware/pwm.c b/firmware/pwm.c
index 4eb2f83..10c03ba 100644
--- a/firmware/pwm.c
+++ b/firmware/pwm.c
@@ -4,7 +4,7 @@
 
 #include "lights.h"
 
-#define PWM_MAX 0x0FF
+#define PWM_MAX 0x1FF
 
 void init_pwm()
 {
@@ -23,10 +23,11 @@ void init_pwm()
 	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;
+	TC1H = PWM_MAX >> 8;		// PWM3 is inverted
 	OCR1D = PWM_MAX & 0xFF;
 
 	TC1H = 0x00;
@@ -45,26 +46,34 @@ 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;
+		TC1H = hi;
+		OCR1A = lo;
 		DDRB |= _BV(PB1);
 		break;
-	case 1: OCR1B = stride;
+	case 1:
+		TC1H = hi;
+		OCR1B = lo;
 		DDRB |= _BV(PB3);
 		break;
-	case 2: {
-			uint16_t s16 = PWM_MAX - (uint16_t)stride;
-			volatile unsigned char hi, lo;
-			hi = s16 >> 8;
-			lo = s16 & 0xFF;
-			TC1H = hi;
-			OCR1D = lo;
-			DDRB |= _BV(PB5);
-		}
+	case 2:
+		TC1H = hi;
+		OCR1D = lo;
+		DDRB |= _BV(PB5);
 		break;
 	}
 }