I hope this isn't a trivial question: when using the Arduino IDE 1.6.6 properly loaded with the ESP 8266 support via the custom URL - does the very first sketch upload replace legacy AT firmware which ESP 8266-01 comes with?
In other words once I upload anything produced by the Arduino IDE, the ESP module won't be usable anymore in its basic AT command mode?
Or does the sketch add on top of the default AT command firmware executing independently and concurrently with anything that the module might be doing as a result of AT commands such as connecting, accepting data, etc?
Thank you!