Having hung-out on this forum for the past year or so, there are a couple of recurring issues that crop up - confusion about the difference between the “D” numbers screen printed on the board and GPIO numbers, and people choosing inappropriate pins.
Maybe including a punout diagram, and discussing the pin numbering issue and how to avoid that pitfall would be a useful addition?
Including this info about “special” pins might be handy:
I think most people come to Blynk thinking that the Arduino boards are the way to go, whereas for most situations the NodeMCU boards are a much better option. However, there are a few situations where the Arduino is a better choice - if you need more analogue or digital pins than you can get with the NodeMCU, or if you’re interfacing with 5v logic levels.
Maybe an intro, or a separate tutorial, about the best choice of board for a particular scenario might also be a good idea?
Pete.