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→Boot Modes et Safe boot
If you power up normally, or press the reset button, the WiPy will boot into standard mode; the {{fname|boot.py}} file will be executed first, then {{fname|main.py}} will run.
If you power up normally, or press the reset button, the WiPy will boot into standard mode; the {{fname|boot.py}} file will be executed first, then {{fname|main.py}} will run.
You can override this boot sequence by pulling {{fname|GP28}} up (connect it to the 3v3 output pin) during reset. This procedure also allows going back in time to old firmware versions. The WiPy can hold up to 3 different firmware versions, which are: the factory firmware plus 2 user updates.
After reset, if {{fname|GP28}} is held high, the heartbeat LED will start flashing slowly, if after 3 seconds the pin is still being held high, the LED will start blinking a bit faster and the WiPy will select the previous user update to boot. If the previous user update is the desired firmware image, {{fname|GP28}} must be released before 3 more seconds elapse. If 3 seconds later the pin is still high, the factory firmware will be selected, the LED will flash quickly for 1.5 seconds and the WiPy will proceed to boot. The firmware selection mechanism is as follows:
Safe Boot Pin {{fname|GP28}} realeased during:
* '''1st 3 secs window''' - Safe boot, ''latest'' firmware is selected
* '''2nd 3 secs window''' - Safe boot, ''previous'' user update selected
* '''Final 1.5 secs window''' - Safe boot, the ''factory'' firmware is selected
On all of the above 3 scenarios, safe boot mode is entered, meaning that the execution of both {{fname|boot.py}} and {{fname|main.py}} is skipped. This is useful to recover from crash situations caused by the user scripts. The selection made during safe boot is not persistent, therefore after the next normal reset the latest firmware will run again.
== La LED heartbeat ==
{{WIPY-TRAILER}}
{{WIPY-TRAILER}}