--- a/main/calibration.h	Sat Oct 20 13:23:15 2018 +0200
+++ b/main/calibration.h	Sat Oct 20 17:09:48 2018 +0200
@@ -14,6 +14,7 @@
  * @param xright X right side  (landscape top)
  * @param ytop Y top           (landscape left)
  * @param ybottom Y botto      (landscape right)
+ * @return 1 if error, 0 if success.
  */
 int TS_set_calibration(int xleft, int xright, int ytop, int ybottom);