Beginner 12 — Carton line (mini-project)

Briefing

Time to build a small project on your own. This carton line has a START button, a STOP button, a photo-eye (BOX_EYE) that pulses once per box, and a CNT_RESET button. Here is how it must behave. Press START and the conveyor waits 2 seconds before MOTOR comes on (the warning pause before a machine moves). Each box that passes BOX_EYE adds one to the count. After five boxes the carton is full: CARTON_FULL lights and the conveyor stops. STOP stops the line at any time, even during the 2 second wait. CNT_RESET clears the count so the next carton can start. The counter and the CARTON_FULL lamp are already built. Two parts of the starter are declared for you: RUN_REQ, a memory bit for "the line was asked to run", and START_DLY, an on-delay timer. Everything you need you have already used in an earlier lab.

Objectives

• START → MOTOR stays off for about 2 seconds, then runs by itself
• STOP stops the line at any time, including during the 2 second wait
• Five BOX_EYE pulses → CARTON_FULL on and MOTOR off
• CNT_RESET clears the carton, then START runs the line again

I/O Table

Your program will be tested against:

All test cases run automatically when you submit. Assertions are hidden until you pass.

1. #1START → MOTOR off for 0.5 s, then on after the delay

   A START pulse starts a 2 second wait; MOTOR comes on only when it ends

2. #2STOP while running → MOTOR off and stays off

   STOP ends the run and nothing restarts it

3. #3STOP during the 2 s wait → MOTOR never starts

   STOP cancels a start that has not finished its delay

4. #4Five boxes → CARTON_FULL on, MOTOR off

   The counter's done output lights the lamp and ends the run

5. #5Three boxes → MOTOR still on, CARTON_FULL off

   Fewer than five boxes does not end the run

6. #6CNT_RESET after a full carton → lamp off, START runs again

   A new carton can begin: reset clears the count, START restarts after the delay