Blackout (80-gpio-wrong-pin)

A colleague wrote a simple LED blinker for PA5. The code compiles cleanly and the logic looks correct: GPIO is configured as output, the pin is toggled in a loop, and there's a delay between transitions. But the LED never turns on. It's completely dark.

The starter code should blink PA5 five times (5 ON/OFF cycles = 10 transitions). Find and fix the bug so the LED blinks as expected.

This is the most common "first day on the job" embedded bug. When everything looks right but nothing happens, think about what the peripheral needs before it can accept register writes.