Hi Pete.
Finally I am not able to flash sonoff. Something happened at hardware level because now I cannot connect it again to my computer. No lights on. I think it died.
Then now I will go for Arduino which is easier to flash. I read your link about boards and due to my inexperience soldering, i am thinking to buy following board. What do you think?
My idea is to use the sketch from this link
From Hagay or Arizona users. Hagay used sonoff then I supposed I will need to change something in the sketch.
I will read more to make less questions.
Thks a lot for your support and sorry for bordering you.