Added check for valid data before returning.

Make sure the temperature are within spec; +/- 200 for temperature and 0..100
for humidity.  If the data is not correct, retry twice.

It appears that there is some initial data in the buffer that is not temp or
humidity when a computer is first booted up.  This retry mechanism clears out
the buffer until there is reasonable data in the pipe.

lascar.c

@@ -66,7 +66,17 @@ get_reading_r(HIDInterface* hid, char* packet,
 
     *hum = get_hum((unsigned)packet[1]);
 
-    return ret;
+    /* check to make sure the values found are within spec, otherwise retry */
+    if(*temp >= -200.0 && *temp <= 200.0 && *hum >= 0.0 && *hum <= 100.0) {
+        return ret;
+    } else if(retries) {
+        /* if the values were bad, try another two times before giving up */
+        /*fprintf(stderr,
+                  "Bad values for temp (%.1f) and hum (%.1f)\n", temp, hum);*/
+        return get_reading_r(hid, packet, temp, hum, get_f, 2);
+    } else {
+        return HID_RET_NOT_FOUND;
+    }
 }
 
 HIDInterface* init_termo(HIDInterface* hid) {