Fix temperature measurement

soft/ds18b20.c

@@ -62,6 +62,6 @@ void gettemp(void){
 	
 	_1WireInit();
 	_1WireWriteByte(0xcc);
-	_1WireWriteByte(0x44);
+	_1WireWriteBytePR(0x44);
 	atomic_set_uint(&System.timers.owire, ms(4000));
 }