1. Can you explain about the gpio 'D' prefix. What are the rules dictating and governing its use?
2. After reformating my serial dev kit module and then waiting the prescribed 30 seconds before reboot, I notice the blue led gives a single quick blink just before 30 secs, so I assume whatever it's been doing is the reason for needing to wait for the 30 sec reboot delay.
But what is the reason for needing to wait 2 minutes after the reboot before starting the reflash?
It seems like a lifetime when painfully holding the nodeMCU button in - and not even the reformat or reflash process takes anywhere near that length of time to carry out their entire process.
So is there a specific reason for needing to wait the 2 minutes delay after reformat before reflash?