Modules:
RS232 FTDI
ESP8266
Warning! ESP8266 does not support 5V on either of its pins.
Connecting the ESP8266 to FT232RL FTDI USB to TTL Serial+Adapter:- VCC = 3.3V (might require a separate power supply for the ESP8266 module, because the FTDI might not give enough current)
- GND = ground
- CH_PD = Chip enable, connect to +VCC
- RST = Leave floating
- GPIO0 = Normally floating but this needs to be connected to GND when flashing the ESP8266 module
- UTXD = Tx data connect to TX of FTDI
- URXD = Rx data connect to RX of FTDI
Flashing ESP8266 module with XTCOM_UTILITY:
Run the program and go to Tools->Config device. Select the Com port of FTDI adapter (only Com ports COM1-COM6 are supported - change port in Windows control panel if necessary). The port used by FTDI adapter is visible in Device Manager. In my case the port was COM2 and the speed was set to 115200. Press Open button to open the COM port and then click Connect.
Go to API TEST->Flash Image Download. Press Browse to select the firmware image and then press the Download button to start flashing.
Flash image file info output when using AT+GMR command:
AT version:0.21.0.0 SDK version:0.9.5
References: tutorial from iot-playground.com, images from stak.com and arduino-info.wikispaces.com
Similar tutorial: developer.mbed.org