X-Git-Url: https://www.fi.muni.cz/~kas/git//home/kas/public_html/git/?p=bike-lights.git;a=blobdiff_plain;f=firmware%2Fambient.c;h=904f2161f5fba06f4b27f38cf23b6a9c2b90417d;hp=aca12577fd1f4876549232b817e48eda534360f4;hb=5a5088f09ea11dd3c36f3bb6833a0c5d85715641;hpb=245a5fcfa3da6628a5634a9899913c0be143ffa9

diff --git a/firmware/ambient.c b/firmware/ambient.c
index aca1257..904f216 100644
--- a/firmware/ambient.c
+++ b/firmware/ambient.c
@@ -3,10 +3,12 @@
 
 #include "lights.h"
 
-#define AMBIENT_VAL_SHIFT 2
-static uint16_t ambient_val, ambient_val16;
+#define AMBIENT_FAST_SHIFT 2	// running avg of ADC vals
+#define AMBIENT_SLOW_SHIFT 6	// 1 << AMBIENT_SLOW_SHIFT times slower
+
+static uint16_t ambient_fast, ambient_slow;
 volatile unsigned char ambient_zone;
-static unsigned char ambient_min, ambient_max, ambient_16drop;
+static unsigned char ambient_min, ambient_max, ambient_drop;
 
 /* logging */
 #define AMBIENT_LOG_SIZE 128
@@ -16,7 +18,7 @@ static unsigned char ambient_log[AMBIENT_LOG_SIZE] EEMEM;
 
 /* My photodiode reads 0x00C5 .. 0x033B */
 typedef struct {
-	uint16_t lo, hi;
+	uint16_t lo, hi; // TODO: consider changing this to bytes
 } ambient_zone_t;
 
 /*
@@ -24,20 +26,20 @@ typedef struct {
  * and having small overlaps in order to provide a bit of hysteresis.
  */
 static ambient_zone_t ambient_zones[N_AMBIENT_ZONES] = {
-	{ 0x0000                   , 0x0250<<AMBIENT_VAL_SHIFT }, // dark
-	{ 0x0240<<AMBIENT_VAL_SHIFT, 0x02e0<<AMBIENT_VAL_SHIFT }, // evening
-	{ 0x02c0<<AMBIENT_VAL_SHIFT, 0x0306<<AMBIENT_VAL_SHIFT }, // dawn
-	{ 0x02f8<<AMBIENT_VAL_SHIFT, 0xffff                    }, // day
+	{ 0x0000, 0x0250 }, // dark
+	{ 0x0240, 0x02e0 }, // evening
+	{ 0x02c0, 0x0306 }, // dawn
+	{ 0x02f8, 0xffff }, // day
 };
 
 void init_ambient()
 {
-	ambient_val = 0;
-	ambient_val16 = 0;
+	ambient_slow = 0;
+	ambient_fast = 0;
 	ambient_max = 0;
 	ambient_min = 0xFF;
 	ambient_zone = 1;
-	ambient_16drop = 0;
+	ambient_drop = 0;
 
 	ambient_log_offset = eeprom_read_byte(&ambient_log_offset_stored);
 
@@ -62,13 +64,22 @@ void ambient_log_min_max()
 	if (ambient_log_offset >= AMBIENT_LOG_SIZE - 1)
 		return;
 
-	// eeprom_write_byte(&ambient_log[ambient_log_offset++], ambient_min);
-	eeprom_write_byte(&ambient_log[ambient_log_offset++], ambient_max);
-	eeprom_write_byte(&ambient_log[ambient_log_offset++], ambient_16drop);
+	ambient_max -= ambient_min;
+	ambient_max >>= 2;
+	if (ambient_max > 15)
+		ambient_max = 15;
+
+	ambient_drop >>= 2;
+	if (ambient_drop > 15)
+		ambient_drop = 15;
+
+	eeprom_write_byte(&ambient_log[ambient_log_offset++], ambient_min);
+	eeprom_write_byte(&ambient_log[ambient_log_offset++],
+		(ambient_max << 4) | ambient_drop);
 
 	ambient_min = 0xFF;
 	ambient_max = 0;
-	ambient_16drop = 0;
+	ambient_drop = 0;
 }
 
 static inline void ambient_zone_changed()
@@ -77,42 +88,64 @@ static inline void ambient_zone_changed()
 	pattern_reload();
 }
 
-void ambient_adc(uint16_t adcval)
+static unsigned char val_to_zone(uint16_t ambient_val)
 {
-	unsigned char old_zone = ambient_zone;
-	unsigned char byte_val, byte_val16;
+	unsigned char new_zone = ambient_zone;
 
-	ambient_val += adcval - (ambient_val
-		>> (AMBIENT_VAL_SHIFT - AMBIENT_ADC_SHIFT));
+	while (ambient_zones[new_zone].lo > ambient_val)
+		new_zone--;
+
+	while (ambient_zones[new_zone].hi < ambient_val)
+		new_zone++;
+
+	return new_zone;
+}
 
-	while (ambient_zones[ambient_zone].lo > ambient_val)
-		ambient_zone--;
+void ambient_adc(uint16_t adcval)
+{
+	unsigned char new_zone, user_zone;
+	unsigned char byte_fast, byte_slow, drop;
+	uint16_t a_10bit;
 
-	while (ambient_zones[ambient_zone].hi < ambient_val)
-		ambient_zone++;
+	// running avg - shorter timespan
+	ambient_fast += adcval - (ambient_fast >> AMBIENT_FAST_SHIFT);
 
-	byte_val = ambient_val >> (2 + AMBIENT_VAL_SHIFT - AMBIENT_ADC_SHIFT);
+	// running avg - longer timespan
+	a_10bit = ambient_fast >> (AMBIENT_FAST_SHIFT + AMBIENT_ADC_SHIFT);
+	ambient_slow += a_10bit - (ambient_slow >> AMBIENT_SLOW_SHIFT);
 
-	ambient_val16 += byte_val - (ambient_val16 >> 4);
-	byte_val16 = ambient_val16 >> 4;
+	// ambient zones are governed by shorter timespan by default
+	new_zone = val_to_zone(a_10bit);
 
-	if (byte_val16 > byte_val) {
-		byte_val16 -= byte_val;
-		if (byte_val16 > ambient_16drop)
-			ambient_16drop = byte_val16;
+	if (new_zone > 1 && (
+		new_zone == ambient_zone-1 || new_zone == ambient_zone+1)) {
+		// but change to the neighbouring zone is governed by _slow,
+		// except to the darkest zone, where we want fast reaction.
+		new_zone = val_to_zone(ambient_slow >> AMBIENT_SLOW_SHIFT);
 	}
 
-	if (ambient_min > byte_val)
-		ambient_min = byte_val;
+	// user_param ambient zone override
+	if ((user_zone = get_user_param(0)) > 0)
+		new_zone = user_zone - 1;
 
-	if (ambient_max < byte_val)
-		ambient_max = byte_val;
+	// TODO: maybe use these values instead of 10-bit?
+	byte_fast = a_10bit >> 2;
+	byte_slow = ambient_slow >> (AMBIENT_SLOW_SHIFT + 2);
 
-	// user_param ambient zone override
-	if ((byte_val = get_user_param(0)) > 0)
-		ambient_zone = byte_val - 1;
+	if (byte_slow > byte_fast) {
+		drop = byte_slow - byte_fast;
+		if (drop > ambient_drop)
+			ambient_drop = drop;
+	}
+
+	if (ambient_min > byte_fast)
+		ambient_min = byte_fast;
+
+	if (ambient_max < byte_fast)
+		ambient_max = byte_fast;
 
-	if (old_zone != ambient_zone) {
+	if (new_zone != ambient_zone) {
+		ambient_zone = new_zone;
 #if 0
 		log_byte(0xab);
 		log_byte(ambient_zone);