add PIR motion check

Sample.bs2

@@ -1,6 +1,7 @@
 ' {$STAMP BS2}
 ' {$PBASIC 2.5}
 
+PirMotion PIN 9
 Spkr PIN 10
 ' DTMF output on pin 10
 #SELECT $STAMP
@@ -29,6 +30,7 @@ hiLo VAR Bit ' Bit to select upper and lower nib
 
 cntA VAR Byte
 repeatA VAR Byte
+countDown VAR Byte
 
 Parallax DATA $19,$16,$62,$48,$33,$3F ' Phone: 1-916-624-8333
 ParallaxFax DATA $19,$16,$62,$48,$00,$3F ' Phone: 1-916-624-8003
@@ -58,8 +60,24 @@ Dial_Number:
   RETURN
 
  Buzzer:
+  INPUT 9
   FOR repeatA = 0 TO 5
-   PAUSE 20000
+
+ ResetCount:
+  countDown = 20
+ Hold:
+  IF IN9 = 1 THEN Hold    ' Motion detected, wait until no motion
+
+  DO
+    DEBUG "*"
+    countDown = countDown - 1
+
+    DEBUG "State of IN9: ", #IN9      ' PIR sensor input
+    IF IN9 = 1 THEN ResetCount     ' Motion detected, restart countdown
+
+    PAUSE 1000
+  LOOP UNTIL (countDown < 0)
+
    OUTPUT 10
    FOR cntA = 0 TO 10
     OUT10=1