arduino sketch: fix loading of status after lack of power

1 files changed, 7 insertions, 5 deletions

diff --git a/arduino_sketch/fuzzy_alarm_clock_ds1307/fuzzy_alarm_clock_ds1307.pde b/arduino_sketch/fuzzy_alarm_clock_ds1307/fuzzy_alarm_clock_ds1307.pde
index 090f14e..1b5fd89 100644
--- a/arduino_sketch/fuzzy_alarm_clock_ds1307/fuzzy_alarm_clock_ds1307.pde
+++ b/arduino_sketch/fuzzy_alarm_clock_ds1307/fuzzy_alarm_clock_ds1307.pde
@@ -44,7 +44,7 @@
 int st = 0; // alarm status (minutes from alarm - TIN)
 char alarms[NALARMS][5]; // alarm settings
 char cmin; // current minute
-int a = -1; // current alarm
+signed char a = -1; // current alarm
 char dbg = 0; // print debug informations
 bool ringing = false; // sound the alarm
 bool pressed = false; // stop button status
@@ -88,10 +88,12 @@ void setup () {
         cmin = RTC.readData(0x0a);
         // This only works if the arduino had no power for a 
         // "short" time. This is by design. :D
-        RTC.readClock();
-        st = st + (RTC.getMinutes() - cmin) % 60;
-        cmin = RTC.getMinutes();
-        save_status();
+        if ( a >= 0 ) {
+            RTC.readClock();
+            st = st + (RTC.getMinutes() - cmin) % 60;
+            cmin = RTC.getMinutes();
+            save_status();
+        }
         for ( int i = 0; i < NALARMS ; i ++ ) {
             for ( int j = 0; j < 5 ; j ++ ) {
                 alarms[i][j] = RTC.readData(0x0b + i*5 + j);