A lot of informations are available about ESP hardware over Internet … sometimes confusing, here is my experience’s about ESP8266 soldering and flashing, especially ESP-03 SMD version, first i use SMD adapters, Futurlec, 14 Pin SSOP Adapter has a perfect match, and are very cheap, the pin of SMD version didn’t match with standard pin header 2.54mm
1) Make connections bellow, between FTDI adapter 3.3v and ESP8266, sometimes some people use external power, in my case it work fine without.
3.3v => 3.3v
CH_PD => 3.3v
RX => TX
TX => RX
Gnd => Gnd
GPIO0 => Gnd (for prog operation)
GPIO15 => Gnd (for normal and prog operation)
2) Download and run XTCOM_UTIL
3) Go to Tools, Config Device, Select Com port (in my case COM2), Baud rate 115200, then select Open.3) Clic on Connect, (never close Config Device window), if its doesn’t work, check if CH_PD is correctly connected to 3.3v and if Tx/Rx are not crossed.4) Go to Flash Image Download, and select the firmware, in my case i use: AI-v0.9.5.0 AT (again, never close Config Device window) 5) Start Download … and wait around two minutes … 6) When it’s finish, disconnect your module and tested with CoolTerm or your favorite terminal software.