Is there a simple way to figure out the on-board ESP-12 firmware via Arduino IDE?
edit: answering myself... ESP has just a bootloader inside so it really doesn't matter what's loaded afterwards as long as it loads without error. So if my sketch compiles and loads via Arduino IDE, and one wemos D1 R1 performs ok while the other doesn't may point to some hardware problem with one of them.
Now, bootloader version is irrelevant I hope?