Could someone please explain if I (naively) loaded NODEMCU on my ESP8266 wifi shield can I revert it back to normal SDK firmware to run AT Commands ?
Background.
Bought a clone ESP8266 WIFI shield (UNO/MEGA) with the 4 pin dip switch and references non existing website elecshop.ml . Long story short it did not work properly on arrival, contacted vendors and they sent NODEMCU flashing tool, this did not work too, but armed with this info, I downloaded latest NODEMCU and flashed the shield and did not realise I would get LUA..... not AT command set.
So I am trying to load SDK and AT using ESP8266 download tool (from Espressif) onto the shield, but it always fails on SYNC !! So the shield is never recognised. I can reload NODEMCU without too many probs. But I need the AT command set not LUA.
Hardware - the shield is plugged into an UNO which ONLY provides power. I then communicate with the ESP8266 via the shield debug port through an FTDI module to a PC.
Only have RXD, TXD and GND connected between ESP8266 and FTDI. I think all connection ok and NODEMCU works, but as above cannot run ESP8266 download tool beyond SYNC.
Thanks
BTW - I posted this on ESP forums but my post is sitting a few days awaiting moderation.
Sure you can. You can always load firmware on your esp8266. I have no idea what shield you have but I am unsure why you would want to use AT-commands.
Just program the chip through the Arduino IDE.
If you want more help post pictures of the board and screenshots of errors you are getting. I cannot guess what the errors are or what commands your are giving it.