Sin título

Start

Button pressed?

No

Yes

Keep standing by

Internal or external?

Internal

External

Internal button working?

Yes

No

Proceed to indicated floor.

4 second period for each floor

Up or down?

Up

Down

Move up in a 4 second period

Move down in a 4 second period

Open elevator doors

Wait 3 seconds

Close elevator doors

Add one to counter

One or two floors crossed?

Two

One

Add two to counter

Counter>=20

Yes

No

Turn LED on

Reset activated?

Yes

No

Counter=0