X-Git-Url: https://www.fi.muni.cz/~kas/git//home/kas/public_html/git/?a=blobdiff_plain;ds=sidebyside;f=firmware%2Ffirmware.c;h=3554dcc768e38e6deda7bdd7fe5fb8459e52a2c2;hb=b6aa72c62905573d4558d11973b5180e112f44d8;hp=8e973510ae55d1577ecc28b2ec2b413d85d59f43;hpb=0c9ed6a110149013fd3690338fac0b33f760e0ed;p=openparking.git

diff --git a/firmware/firmware.c b/firmware/firmware.c
index 8e97351..3554dcc 100644
--- a/firmware/firmware.c
+++ b/firmware/firmware.c
@@ -25,6 +25,7 @@
 #define free_bitmap	(hold_regs[MB_N_HOLD_REGS_EEPROM+13])
 #define err_bitmap	(hold_regs[MB_N_HOLD_REGS_EEPROM+14])
 #define max_distances	(hold_regs+MB_N_HOLD_REGS_EEPROM+21)
+#define err_counts	(hold_regs+MB_N_HOLD_REGS_EEPROM+41)
 
 static void pull_trigger(uint8_t trig)
 {
@@ -104,16 +105,32 @@ static void do_measurement(unsigned char trig)
 		}
 	}
 
-	for (i = 0; i < N_TRIG_SENSORS; i++)
-		if (to_start & (1 << i))
-			distances[trig*N_TRIG_SENSORS + i] = -1;
-		else if (to_measure & (1 << i))
+	for (i = 0; i < N_TRIG_SENSORS; i++) {
+		uint8_t off = trig*N_TRIG_SENSORS + i;
+
+		if (to_start & (1 << i)) { // echo not received
+			uint16_t err_count = err_counts[off] & 0xFF;
+			if (distances[off] != -1 && err_count < 255) {
+				err_count++;
+				err_counts[off] = (err_counts[off] & 0xFF00)
+					| err_count;
+			}
+			distances[off] = -1;
+		} else if (to_measure & (1 << i)) { // echo pulse too long
+			uint16_t err_count = err_counts[off] >> 8;
+
+			if (err_count < 255) {
+				err_count++;
+				err_counts[off] = (err_counts[off] & 0x00FF)
+					| (err_count << 8);
+			}
 			/*
 			 * If the echo pulse is too long, do not treat it
 			 * as error, just count it as maximum length.
 			 */
-			distances[trig*N_TRIG_SENSORS + i]
-				= now - starttimes[i];
+			distances[off] = now - starttimes[i];
+		}
+	}
 }
 
 static void led_set(uint8_t led, uint8_t state)
@@ -170,9 +187,9 @@ static void leds_update()
 	}
 
 	if (led_bitmap & 8) {
-		DDRB |= _BV(PB5);
-	} else {
 		DDRB &= ~_BV(PB5);
+	} else {
+		DDRB |= _BV(PB5);
 	}
 }