From: Jan "Yenya" Kasprzak <kas@fi.muni.cz>
Date: Sun, 16 Dec 2012 16:29:53 +0000 (+0100)
Subject: ambient light: make three measurements
X-Git-Url: https://www.fi.muni.cz/~kas/git//home/kas/public_html/git/?p=bike-lights.git;a=commitdiff_plain;h=dd1738d1117607d5a47050274d805748b11f48d1

ambient light: make three measurements
---

diff --git a/firmware/adc.c b/firmware/adc.c
index f5d846f..4213ef5 100644
--- a/firmware/adc.c
+++ b/firmware/adc.c
@@ -33,7 +33,7 @@ static void inline setup_mux(unsigned char n)
 		break;
 	case 3: // ambient light: 1.1V, ADC5 (PA6), single-ended
 		ADMUX = _BV(REFS1) | _BV(MUX2) | _BV(MUX0);
-		sum_shift = 0; // 1 measurement
+		sum_shift = 3; // 3 measurements
 		break;
 	case 4: // batt voltage: 1.1V, ADC6 (PA7), single-ended
 		ADMUX = _BV(REFS1) | _BV(MUX2) | _BV(MUX1);
@@ -146,7 +146,7 @@ ISR(ADC_vect) { // IRQ handler
 	if (current_adc < N_PWMLEDS)
 		pwmled_adc(current_adc, adc_sum);
 	if (current_adc == AMBIENT_ADC)
-		ambient_adc(adcval);
+		ambient_adc(adc_sum);
 	if (current_adc == BATTERY_ADC)
 		battery_adc(adcval);
 	
diff --git a/firmware/ambient.c b/firmware/ambient.c
index c6c6a65..735f80e 100644
--- a/firmware/ambient.c
+++ b/firmware/ambient.c
@@ -15,8 +15,8 @@ typedef struct {
  * and having small overlaps in order to provide a bit of hysteresis.
  */
 static ambient_zone_t ambient_zones[] = {
-	{ 0x0000, 0x3120 }, // dark
-	{ 0x30f0, 0x5000 },
+	{ 0x0000, 0x3400 }, // dark
+	{ 0x3300, 0x5000 },
 	{ 0x4c00, 0x8000 },
 	{ 0x7800, 0xffff }
 };
@@ -46,7 +46,7 @@ void ambient_adc(uint16_t adcval)
 {
 	unsigned char old_zone = ambient_zone;
 
-	ambient_val += adcval - (ambient_val >> 6);
+	ambient_val += adcval - (ambient_val >> 3);
 
 	while (ambient_zones[ambient_zone].lo > ambient_val)
 		ambient_zone--;