spurious temperature readings don't get passed to user code...need to do something about spurious clock readings next

git-svn-id: https://svn.salfter.gotdns.org/svn/a2bfc/trunk@147 1b90f75b-8b96-4784-87c0-14078182fce6

ow-temp.c

@@ -24,7 +24,9 @@
 short ow_temp_read(unsigned char* devid, unsigned char format)
 {
   unsigned char data[8];
-  short rawtemp;
+  static int lasttemp=-32767;
+  int newtemp;
+  int rawtemp;
   unsigned char i;
 
   if (!ow_temp_idcheck(devid))
@@ -40,17 +42,27 @@ short ow_temp_read(unsigned char* devid, unsigned char format)
   for (i=0; i<8; i++)
     data[i]=ow_readbyte();
   
-  rawtemp=(short)(data[0]+((int)data[1]<<8));
+  rawtemp=((int)data[0]+((int)data[1]<<8));
   errno=0;
   switch (format)
   {
   case OW_TEMP_FAHRENHEIT:
-    return (rawtemp*9+8)/80+32;
+    newtemp=(rawtemp*9+8)/80+32;
+    break;
   case OW_TEMP_CELSIUS:
-    return (rawtemp+8)>>4;
+    newtemp=(rawtemp+8)>>4;
+    break;
   case OW_TEMP_RAW:
   default:
-    return rawtemp;
+    return (short)rawtemp;
+  }
+  /* 17 Aug 08: filter out garbage readings */
+  if ((newtemp-lasttemp>3 || newtemp-lasttemp<-3) && lasttemp!=-32767)
+    return (short)lasttemp;
+  else
+  {
+    lasttemp=newtemp;
+    return (short)newtemp;
   }
 }