This posts shows the steps needed in order to communicate with the ESP8266 module from the PC, using PuTTY. You will be able to write AT commands and see the output. This may be useful for various usages, e.g. for checking the version of the firmware, or for more advanced understanding and debugging operations.

SEE ALSO This post, for step by step instructions on how to flash a new AT Commands firmware to your ESP8266 module.

Hardware Used

Same as here.


Same as here. The 2 wires at the bottom (IO0, IO2) are not needed/should be removed.

In our setup, we used a 5V FTDI programmer and a voltage regulator to power the board. The circuit looks like this:



Download PuTTY terminal (putty.exe) from here, save it on your local disk.

Sending AT Commands (e.g. checking firmware version)

1 Power on the circuit.

2 Start PuTTY, click on the Serial radio button. In the Serial line text box type the COM port of your FTDI programmer (e.g. COM3). In the Speed text box type 115200. Then, click the Open button.


HINT Depending on your firmware version, the baud rate of the ESP8266 chip is usually set to either 9600 bps or 115200 bps. Recent firmware versions set the baud rate to 115200 bps by default, so if your chip is set to communicate at a different speed, you probably need to update the firmware.

3 After the serial port is open, type AT commands, followed by ENTER and <CTRL + J>.

E.g. to check the firmware version, you need to type AT+GMR, ENTER and <CTRL + J>. The firmware version should appear in the terminal window, as illustrated below.

The reference documentation (and examples) for AT commands can be found here.


HINT If you see unreadable characters in the terminal window, it means that the baud rate of your ESP8266 is not correct (e.g. 115200 bps in our case). If that’s the case, your ESP8266 is most probably running a very old firmware, and you should proceed with updating the firmware. If you still want to check the firmware version, repeat the steps above trying different speeds (9600 bps is a good starting point). If you need to see the bootloader’s output, you have to open the serial port at 76800 bps.