From f6117273f63c0545b45d2a2b6e86a4e4e68cb7c8 Mon Sep 17 00:00:00 2001
From: "Jan \"Yenya\" Kasprzak" <kas@fi.muni.cz>
Date: Thu, 23 Aug 2012 10:54:50 +0200
Subject: [PATCH] multi-mode light

---
 lights.c | 117 +++++++++++++++++++++++++++++++------------------------
 1 file changed, 67 insertions(+), 50 deletions(-)

diff --git a/lights.c b/lights.c
index 78bd2e1..d05fa1c 100644
--- a/lights.c
+++ b/lights.c
@@ -5,22 +5,25 @@
 #include <avr/interrupt.h>
 
 volatile uint16_t adcval;
-unsigned char pwmval = 0x10;
-volatile uint16_t adc_exp = 0x10;
 unsigned char led_is_on = 0;
 volatile unsigned char adccount = 0;
 
-volatile struct
-{
-  uint8_t pwm_int: 1;
-  uint8_t adc_int: 1;
-  uint8_t tmr_int: 1;
-}
-intflags;
+typedef struct {
+	unsigned char pwmval, expected;
+} led_level_t;
+
+led_level_t led_modes[2] = {
+	{ 0x50, 0x38 },
+	{ 0x38, 0x04 },
+};
+
+unsigned char led_mode = 0;
+unsigned char led_mode_changed = 0;
 
 static void inline led_on()
 {
         DDRB |= _BV( PB5 );
+	PORTA |=  _BV( PA0 );
 	led_is_on = 1;
 }
 
@@ -28,6 +31,7 @@ static void inline led_off()
 {
 	led_is_on = 0;
         DDRB &= ~_BV( PB5 );
+	PORTA &=~  _BV( PA0 );
 //        ADCSRA &= ~(_BV(ADIE) | _BV(ADIF));
 }
 
@@ -72,7 +76,7 @@ static void log_word(uint16_t word) {
 
 /* ------------ Timer ----------- */
 
-volatile uint16_t clock = 0;
+volatile uint16_t jiffies = 0;
 
 static void inline init_tmr()
 {
@@ -82,35 +86,42 @@ static void inline init_tmr()
 	TIMSK |= _BV(OCIE0A);
 	DDRA |= _BV( PA0 );
 
-	clock = 0;
+	jiffies = 0;
 }
 
 static void inline tmr_handler()
 {
-	unsigned char c = clock & 0x1F;
-	unsigned char c1 = clock & 0xFF;
+	unsigned char c = jiffies & 0x0F;
+	unsigned char c1 = jiffies & 0x7F;
+
+	++jiffies;
 
-	++clock;
 #if 0
-	if (c == 10 || c == 30) 
+	if (c == 1)
 		led_on();
 
-	if (c == 20 || c == 40)
+	if (c == 9)
 		led_off();
 #endif
 
 	if (c == 0x02 || c == 0x08)
 		led_on();
+		
 	if (c == 0x05 || c == 0x0b)
 		led_off();
 
-	if ((clock & 0x7F) == 0x1F) {
-		if (c1 < 0x80) {
-			adc_exp = 0x80;
-		} else {
-			adc_exp = 0x20;
-		}
+#if 1
+	if (c1 == 0x10) {
+		led_mode = 0;
+		led_mode_changed = 1;
+		OCR1D = led_modes[led_mode].pwmval;
+	} else if (c1 == 0x70) {
+		led_mode = 1;
+		led_mode_changed = 1;
+		OCR1D = led_modes[led_mode].pwmval;
 	}
+#endif
+
 	ADCSRA |= _BV(ADSC);
 #if 0
 	if (led_is_on && adcval != 0xFFEE) {
@@ -144,9 +155,9 @@ static void inline init_pwm()
 		| _BV(CS10) 			// no clock prescaling
 		;
 	OCR1C = 0xFF;				// TOP value
-	OCR1D = OCR1B = OCR1A = pwmval;
+	OCR1D = OCR1B = OCR1A = 0;
 	// OCR1D = 0;
-	// DDRB |= _BV( PB5 );
+	DDRB |= _BV( PB5 );
 	PORTB &= ~(_BV( PB5 ) | _BV( PB1 ) | _BV( PB3 ));
 
 	// led_off();
@@ -186,32 +197,35 @@ static void inline init_adc()
 
 static void inline adc_handler()
 {
-	uint16_t new_pwm = pwmval;
-	uint16_t old_pwm = pwmval;
-	uint16_t old_adc = adcval;
+	uint16_t new_pwm = led_modes[led_mode].pwmval;
+	uint16_t old_pwm = new_pwm;
+	uint16_t adc_exp = led_modes[led_mode].expected;
+
 	adcval = ADCW;
 	adccount++;
 
 	// log_word(((adcval & 0x3FC) << 6) | pwmval);
-	log_word(((adcval & 0xFF) << 8) | pwmval);
 
 	if (!led_is_on)
 		return;
-	// adcval = (adcval + 3*old_adc)/4;
 
 	// ADCSRA &= ~(_BV(ADIE) | _BV(ADIF));
 
-	if (adcval < 1) {
-		adcval = 1;
-	} else if (adcval > adc_exp) {
-		new_pwm = old_pwm*adc_exp/adcval;
-	} else if (adcval < adc_exp && 2 * adcval > adc_exp) {
-		new_pwm = old_pwm*adc_exp/adcval;
-	} else if (adcval < adc_exp) {
-		new_pwm = 2 * old_pwm;
+	if (led_mode_changed) {
+		led_mode_changed = 0;
+		goto set_pwm;
+	}
+
+	log_word(((adcval & 0xFF) << 8) | old_pwm);
+
+	if (2*adcval > 5*adc_exp) { // >2.5x expected, lower significantly
+		new_pwm = 2*old_pwm/3;
+	} else if (3*adcval > 4*adc_exp) { // >1.33x expected, lower a bit
+		new_pwm = old_pwm - 1;
+	} else if (4*adcval < 3*adc_exp) { // 0.75x expected, raise a bit
+		new_pwm = old_pwm + 1;
 	}
 
-	new_pwm = (3*old_pwm + new_pwm) / 4;
 	if (new_pwm > 0x60) { // odpojeno?
 		new_pwm = 0x60;
 	}
@@ -219,10 +233,11 @@ static void inline adc_handler()
 		new_pwm = 2;
 	}
 
-	// if (new_pwm < 15*old_pwm/16 || new_pwm > 17*old_pwm/16) {
-		pwmval = new_pwm;
-		OCR1D = pwmval;
-	// }
+set_pwm:
+	if (new_pwm != old_pwm) {
+		led_modes[led_mode].pwmval = new_pwm;
+		OCR1D = new_pwm;
+	}
 	// ADCSRA |= _BV(ADSC);
 }
 
@@ -233,24 +248,26 @@ ISR(ADC_vect)
 
 int main(void)
 {
+	_delay_ms(1500);
 	init_log();
 
 	init_pwm();
 	init_adc();
 	init_tmr();
 
-	debug_setstate(2);
+	led_on();
+	debug_setstate(3);
 
 	sei();
 	while (1)
-		;// sleep_mode();
+		; // sleep_mode();
 
 #if 0
-    DDRA |= _BV( PA0 );
-    while( 1 ) { 
-        PORTA |=  _BV( PA0 );
-        _delay_ms(200);
-        PORTA &=~ _BV( PA0 );
-    }
+	while (1) {
+		PORTA |=  _BV( PA0 );
+		_delay_ms(200);
+		PORTA &=~ _BV( PA0 );
+		_delay_ms(200);
+	}
 #endif
 }
-- 
2.39.3