Dear @Hallston I'm happy that, at the end, has worked !
Enjoy your "self made" pedal system. But please be aware that if you'l still have bouncing of the signal being read, a filter on Arduino side, as @davidefa has alerady suggested, could be necessary. In effect the Arduino forum has plenty of "debouncing" methods that you can easily imlpement. They could be based on repaeated readings or on a time base. Anyway, that's another story. Best wishes 
ok, i will try reoving the "debounce Delay", thank you all so uch
EDIT: "M" key sometimes doesn't register