From: Jan "Yenya" Kasprzak <kas@fi.muni.cz>
Date: Fri, 30 Nov 2012 10:23:27 +0000 (+0100)
Subject: adc: always-running ADC
X-Git-Url: https://www.fi.muni.cz/~kas/git//home/kas/public_html/git/?p=bike-lights.git;a=commitdiff_plain;h=210916486d18b3dc976c65c7b01b44bca446d856

adc: always-running ADC

Don't rely on the timer IRQ to start next round of ADC measurements,
start it immediately after the previous one finishes.
---

diff --git a/firmware/adc.c b/firmware/adc.c
index fa0782c..b7dad0a 100644
--- a/firmware/adc.c
+++ b/firmware/adc.c
@@ -51,15 +51,15 @@ static void inline setup_mux(unsigned char n)
 
 static void start_next_adc()
 {
-	if (current_adc > 0) {
+	if (current_adc > 0)
 		current_adc--;
-		// set up mux, start one-shot conversion
-		setup_mux(current_adc);
-		ADCSRA |= _BV(ADSC);
-	} else {
-		current_adc = NUM_ADCS;
+	else
 		// TODO: kick the watchdog here.
-	}
+		current_adc = NUM_ADCS-1;
+
+	// set up mux, start one-shot conversion
+	setup_mux(current_adc);
+	ADCSRA |= _BV(ADSC);
 }
 
 void init_adc()
@@ -100,6 +100,8 @@ void init_adc()
 	}
 
 	ADCSRA |= _BV(ADIE); // enable IRQ
+
+	start_next_adc();
 }
 
 void susp_adc()
@@ -151,13 +153,3 @@ ISR(ADC_vect) { // IRQ handler
 	start_next_adc();
 }
 
-void timer_start_adcs()
-{
-	if (current_adc == NUM_ADCS) // Don't start if in progress
-		start_next_adc();
-#if 0
-	else
-		log_byte(0x99);
-#endif
-}
-
diff --git a/firmware/lights.h b/firmware/lights.h
index e525bfd..8187142 100644
--- a/firmware/lights.h
+++ b/firmware/lights.h
@@ -25,7 +25,6 @@ void inline log_word(uint16_t word) { }
 /* adc.c */
 void init_adc();
 void susp_adc();
-void timer_start_adcs();
 
 /* pwm.c */
 #define PWM_MAX 0x1E4 /* This should be different than ADC frequency 125 kHz */
diff --git a/firmware/tmr.c b/firmware/tmr.c
index 37b240b..f0d7d93 100644
--- a/firmware/tmr.c
+++ b/firmware/tmr.c
@@ -36,7 +36,5 @@ ISR(TIMER0_COMPA_vect)
 		patterns_next_tick();
 		pattern_div = PATTERN_DIV;
 	}
-
-	timer_start_adcs();
 }