ESP8266 Community Forum

I try to buy 3 boards from market to start some DIY.
- ESP-12F
- USB TTL (PL2303HX)
- LM2596 (BUCK) for supply 3.3v to ESP

I connect them like this


I already try all of baud rate in list but when power on it return alien message. I type AT then Enter but no any response.
example :


Please help to advise me to solve this.

I try to replace PL2303 by Arduino Leonardo with simple multi serial code as show in below picture.
I got readable message on Serial Monitor but AT-command still not respond.