diff -r d9c5eaf85fab -r 48f29a1d43d6 lib/keypad/Keypad.cpp
--- a/lib/keypad/Keypad.cpp	Mon Oct 04 21:14:39 2021 +0200
+++ b/lib/keypad/Keypad.cpp	Mon Oct 04 21:15:35 2021 +0200
@@ -47,7 +47,7 @@
   {
 	// activate column col
     _columns[col].write(1);
-    ThisThread::sleep_for(5);
+    ThisThread::sleep_for(5ms);
     for(row=0; row<_nrows; row++)
     {
       if (_rows[row].read())
@@ -71,7 +71,7 @@
       }
     _columns[col].write(0);
     col = (col+1) % _ncols;
-    ThisThread::sleep_for(5);
+    ThisThread::sleep_for(5ms);
   }
 }