Fix 04 — Counter won’t reset

Briefing

A packing station counts boxes with an eye. When three boxes have passed, BATCH_FULL lights so the operator can swap the crate. Pressing RESET_PB should clear the count for the next batch. The count and the lamp work, but RESET_PB does nothing, so the lamp stays on for ever. Find out why, and fix it.

Objectives

• The lamp stays off for the first two boxes
• The third box lights BATCH_FULL
• RESET_PB clears the lamp
• The next batch needs three fresh boxes, even after a reset in the middle of a batch

I/O Table

Your program will be tested against:

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

1. #1Two boxes → lamp off

   The batch is three boxes, so two boxes do not fill it

2. #2Three boxes → lamp on

   The third box fills the batch

3. #3RESET after a full batch → lamp off

   Pressing RESET clears the full lamp

4. #4After a reset, three fresh boxes are needed

   The count restarts at zero: two boxes leave the lamp off, the third lights it

5. #5RESET in the middle of a batch → count restarts

   A reset after two boxes throws that count away

6. #6A fourth box → lamp stays on

   A full batch stays full until RESET