From 102f482d8e40e8a1a9a80e8c7be813577b9b9dbd Mon Sep 17 00:00:00 2001
From: john stone <john@tuxcode.org>
Date: Mon, 6 Aug 2012 13:25:33 +0200
Subject: [PATCH] all sample and legacy code thrown out of main

---
 firmware/main.c | 86 +++++++++++++++++++++----------------------------
 1 file changed, 36 insertions(+), 50 deletions(-)

diff --git a/firmware/main.c b/firmware/main.c
index 5a759e9..04da2ca 100644
--- a/firmware/main.c
+++ b/firmware/main.c
@@ -10,42 +10,51 @@
 
 static void init_sampletimer(void)
 {
-	// Timer 0
-	// set timer0 to CTC & prescaler 64 == 125k
+	/* 
+	 * Timer 0
+	 */
+
+	/* set timer0 to CTC & prescaler 64 → 125kHz increment */
 	TCCR0A = (1 << WGM01);
 	TCCR0B = (1 << CS00) | (1 << CS01);
-	// count up to 5 :
-	OCR0A = 3;
+
+	OCR0A = 3; /* TOP */
 	TCNT0 = 0;
-	// enable interrupt
+	/*enable interrupt*/
 	TIMSK0 |=  (1<<OCIE0A);
 }
 
 static inline void init_pwm(void)
 {
-	// PB2 set to output:
-	DDRB |= (1 << PORTB2);
-	OCR1B = 0x001F;		// preselect some default
-	ICR1 = 0x00FF;		// TOP-wert
+	/* set PB2 as output (buzzer pwm port):*/
+	DDRB  |= (1 << PORTB2);
 
-	TCCR1A = (1 << COM1B1) | (1 << WGM11);	// only b-chan , fastpwm (mode 14)
-	TCCR1B = (1 << WGM13) | (1 << WGM12) | (1 << CS10);	// Fastpwm, no prescale
+	/* analog value preselection :*/
+	OCR1B  =  0x007F;
+
+	/* Top value. Timer overflows here. Thus we have a resulting 8bit pwm */
+	ICR1   =  0x00FF;
+
+	/* only b-chan , fastpwm (mode 14), no prescale */
+	TCCR1A = (1 << COM1B1) | (1 << WGM11);	
+	TCCR1B = (1 << WGM13 ) | (1 << WGM12) | (1 << CS10);
 
-	// TIMSK1 |=  (1 << OCIE1B); //enable timer 1 Output compare
 	return;
 }
 
 static void init_leds(void)
 {
-	// enable LED channels as output
-	DDRC |= (1 << PORTC0) | (1 << PORTC2) | (1 << PORTC3) | (1 << PORTC1);
-	PORTC = 1;		//one led is on...
+	/* enable LED channels as output */
+	DDRC |= (1 << PORTC0) | (1 << PORTC2) |
+		(1 << PORTC3) | (1 << PORTC1) ;
+	/* initially one led is on */
+	PORTC = 1;
 	return;
 }
 
 inline void setleds(uint8_t state)
 {
-	// set leds according to
+	/* set leds according to */
 	PORTC |= (state | 0b00001111);
 	PORTC &= ~(state | 0b11110000);
 	return;
@@ -53,8 +62,9 @@ inline void setleds(uint8_t state)
 
 static void init_motor(void)
 {
-	// vibration motor on B1:
-	DDRB |= (1 << PORTB1);
+	/* vibration motor on B1, initially off: */
+	DDRB  |= (1 << PORTB1);
+	PORTB &= ~( 1<<PORTB1);
 
 }
 
@@ -62,51 +72,27 @@ static void init_motor(void)
 
 int main(void)
 {
-
-	// hardware initialisation:
+	/* hardware initialisation: */
 	init_leds();
 	// init_motor();
 	init_pwm();
 	init_sampletimer();
-
+	
+	/* syntesizer initialisation */
 	synth_init();
-	// OCR1B = 0x00F0;
+
+	/* here the show begins:*/
 	sei();
 
-	while(1) {}
+	for(;;) /* ever */  ;
 
-	// never get here
-	return 0;
+	/* never */ return 0;
 }
 
 
-// 25kHz
 ISR(TIMER0_COMPA_vect)
 {
-	// test stuff
-	/*
-	static uint16_t counter = 0;
-	static uint16_t pulsewidth = 0;
-	static uint16_t maxcounter = 0x133;
-	static uint16_t pulsecounter = 0;
-	counter++;
-	if (counter > maxcounter){
-	 	counter = 0;
-	};
-
-	pulsecounter++;
-	if (pulsecounter > 0x300){
-		 pulsecounter = 0;
-		 pulsewidth++;
-		 if (pulsewidth > maxcounter){
-			pulsewidth = 0;
-		}
-	}
-	OCR1B = ((counter > pulsewidth) ? 0xff : 0x00);
-	*/
-
-
+	/* calculate next analog sample value in synth mixer:*/
 	OCR1B = synth_mix();
-
 }