diff --git a/doku.md b/doku.md
index b53daab..d533679 100644
--- a/doku.md
+++ b/doku.md
@@ -56,6 +56,9 @@ else
 
 ### HW issues
 - GPIO2 used as input -> must be high during startup
+- PCB Solution: cut trace to GPIO2, solder bridge to GPIO16
+- -> disadvantage: GPIO16 is not interrupt capable
+
 
 ### FSM 2 - to do
 - stairway light switches off after timeout