From 5d0ab95bb20a304693c1e0ec6c7900b7090d03e2 Mon Sep 17 00:00:00 2001
From: "Jan \"Yenya\" Kasprzak" <kas@fi.muni.cz>
Date: Mon, 3 Jun 2013 14:11:23 +0200
Subject: [PATCH] adc.c: reorder ADC channels

- those which need to be measured more frequently, put at the beginning.
---
 firmware/adc.c | 27 ++++++++++++++-------------
 1 file changed, 14 insertions(+), 13 deletions(-)

diff --git a/firmware/adc.c b/firmware/adc.c
index ef71477..c6b113d 100644
--- a/firmware/adc.c
+++ b/firmware/adc.c
@@ -3,11 +3,12 @@
 
 #include "lights.h"
 
-#define AMBIENT_ADC N_PWMLEDS
-#define BATTERY_ADC (N_PWMLEDS + 1)
-#define ADC1_GAIN20 (N_PWMLEDS + 2)
-#define BUTTON_ADC  (N_PWMLEDS + 3)
-#define ZERO_ADC    (N_PWMLEDS + 4)
+// pwmleds are measured continuously (when active)
+#define AMBIENT_ADC N_PWMLEDS		// measured every jiffy (16 Hz)
+#define BUTTON_ADC  (N_PWMLEDS + 1)	// measured every jiffy (16 Hz)
+#define BATTERY_ADC (N_PWMLEDS + 2)	// once per second
+#define ADC1_GAIN20 (N_PWMLEDS + 3)	// once per second
+#define ZERO_ADC    (N_PWMLEDS + 4)	// must be last
 
 #define NUM_ADCS	ZERO_ADC
 
@@ -20,9 +21,9 @@ struct {
 	{ 0, 1, PWMLED_ADC_SHIFT },	// pwmled 2
 	{ 0, 1, PWMLED_ADC_SHIFT },	// pwmled 3
 	{ 0, 1, AMBIENT_ADC_SHIFT },	// ambient
+	{ 0, 1, 0 },			// buttons
 	{ 0, 1, 0 },			// battery
 	{ 0, 1, 0 },			// gain20
-	{ 0, 1, 0 },			// buttons
 };
 
 volatile static unsigned char current_adc, current_slow_adc;
@@ -47,16 +48,16 @@ static void setup_mux(unsigned char n)
 	case AMBIENT_ADC: // ambient light: 1.1V, ADC5 (PA6), single-ended
 		ADMUX = _BV(REFS1) | _BV(MUX2) | _BV(MUX0);
 		break;
+	case BUTTON_ADC: // buttons: 1.1V, ADC3, single-ended
+		PORTA |= _BV(PA3); // +5V to the voltage splitter
+		ADMUX = _BV(REFS1) | _BV(MUX1) | _BV(MUX0);
+		break;
 	case BATTERY_ADC: // batt voltage: 1.1V, ADC6 (PA7), single-ended
 		ADMUX = _BV(REFS1) | _BV(MUX2) | _BV(MUX1);
 		break;
 	case ADC1_GAIN20: // gain stage offset: 1.1V, ADC1,1, gain 20
 		ADMUX = _BV(REFS1) | _BV(MUX3) | _BV(MUX2) | _BV(MUX0);
 		break;
-	case BUTTON_ADC: // buttons: 1.1V, ADC3, single-ended
-		PORTA |= _BV(PA3); // +5V to the voltage splitter
-		ADMUX = _BV(REFS1) | _BV(MUX1) | _BV(MUX0);
-		break;
 	case ZERO_ADC: // zero: 1.1V, ADC1 (PA1), single-ended
 		ADMUX = _BV(REFS1) | _BV(MUX0);
 		break;
@@ -240,12 +241,12 @@ ISR(ADC_vect) { // IRQ handler
 	case AMBIENT_ADC:
 		ambient_adc(adc_sum);
 		break;
-	case BATTERY_ADC:
-		battery_adc(adc_sum);
-		break;
 	case BUTTON_ADC:
 		button_adc(adc_sum);
 		break;
+	case BATTERY_ADC:
+		battery_adc(adc_sum);
+		break;
 	case ADC1_GAIN20:
 		adc1_gain20_adc(adcval);
 		break;
-- 
2.39.3