From 4c4fe8554a4c770d68dba4b45df716c4d0308a2f Mon Sep 17 00:00:00 2001
From: "Jan \"Yenya\" Kasprzak" <kas@fi.muni.cz>
Date: Fri, 31 Jan 2014 00:25:09 +0100
Subject: [PATCH] battery measurements (off, on)

---
 firmware/main.c | 69 ++++++++++++++++++++++++++++++++++++++-----------
 1 file changed, 54 insertions(+), 15 deletions(-)

diff --git a/firmware/main.c b/firmware/main.c
index afaa557..fcb7426 100644
--- a/firmware/main.c
+++ b/firmware/main.c
@@ -17,11 +17,28 @@ static void timer_init()
 
 	DDRB |= _BV(PB4);
 
-	TCCR1 = _BV(CS10); // clk/1 = 1 MHz
-	// TCCR1 = _BV(CS11) | _BV(CS13); // clk/512 = 2 kHz
+	// TCCR1 = _BV(CS10); // clk/1 = 1 MHz
+	TCCR1 = _BV(CS11) | _BV(CS13); // clk/512 = 2 kHz
 	GTCCR = _BV(COM1B1) | _BV(PWM1B);
 	OCR1C = 255;
-	OCR1B = 0;
+	OCR1B = steps[0];
+	TIMSK = _BV(OCIE1B) | _BV(TOIE1);
+}
+
+volatile unsigned char adc_type, adc_drop;
+
+ISR(TIM1_OVF_vect)
+{
+	adc_drop = 2;
+	adc_type = 1;
+	ADCSRA |= _BV(ADSC);
+}
+
+ISR(TIM1_COMPB_vect)
+{
+	adc_drop = 2;
+	adc_type = 0;
+	ADCSRA |= _BV(ADSC);
 }
 
 static void set_pwm(unsigned char pwm)
@@ -33,11 +50,38 @@ static void adc_init()
 {
 	power_adc_enable();
 
-	ADCSRA = _BV(ADEN) | _BV(ADPS1) | _BV(ADPS0); // clk/8 = 125 kHz
+	ADCSRA = _BV(ADEN) | _BV(ADPS1) | _BV(ADPS0) | _BV(ADIE); // clk/8 = 125 kHz
 	ADMUX = _BV(REFS1) | _BV(MUX1) | _BV(MUX0); // 1.1V ref., PB3 single-ended
 	DIDR0 = _BV(ADC3D);
 }
 
+volatile uint16_t batt_on, batt_off;
+
+ISR(ADC_vect)
+{
+	uint16_t adcw = ADCW;
+
+	if (adc_drop) {
+		adc_drop--;
+		ADCSRA |= _BV(ADSC);
+		return;
+	}
+
+	if (adc_type == 0) {
+		if (batt_off) {
+			batt_off += adcw - (batt_off >> 5);
+		} else {
+			batt_off = adcw << 5;
+		}
+	} else {
+		if (batt_on) {
+			batt_on += adcw - (batt_on >> 5);
+		} else {
+			batt_on = adcw << 5;
+		}
+	}
+}
+
 static void status_led_init()
 {
 	DDRB |= _BV(PB2);
@@ -236,6 +280,11 @@ static void timer_blink()
 		blink_on_time = 0;
 		blink_off_time = 2;
 		blink_counter = 10;
+#if 0
+		log_byte(0xbb);
+		log_byte(batt_on >> 7);
+		log_byte(batt_off >> 7);
+#endif
 	}
 }
 
@@ -245,17 +294,6 @@ int main()
 
 	power_down();
 
-#if 0
-	ADCSRA |= _BV(ADSC);
-	while (!(ADCSRA & _BV(ADIF)))
-		;
-	log_word(ADCW);
-	ADCSRA |= _BV(ADSC);
-	while (!(ADCSRA & _BV(ADIF)))
-		;
-	log_word(ADCW);
-	log_flush();
-#endif
 	sei();
 
 	// we try to be completely IRQ-driven, so just wait for IRQs here
@@ -272,6 +310,7 @@ int main()
 			wdt_timer_fired = 0;
 			timer_check_buttons();
 			timer_blink();
+			log_flush();
 		}
 	}
 }
-- 
2.39.3