ESP8266 Community Forum

iam new user of esp8266 and i face problem with esp8266 module for connection with TTL but doesnt work because of issue about the 5v TX from TTL usb module so i bought development esp8266 kit http://nodemcu.com/index_en.html to get of headache of voltage regulators and buffers ic but when i updated firmware i didn’t get any respond from putty connection like ready however i change the baud rate from 9600 to 230400 i rest it many times and change the firmware to the default one.
so what could be the problem

First things first: a good thing you bought a real development board; it makes things much easier when you're new.

1. Connect your NodeMCU, make a note of the COM-port number (I'll take COM4 as an example here)
2. In PuTTY, create a profile with the following settings:
   • Connection type: Serial
   • Serial line: [YOUR COMPORT] eg. "COM4" (without the qoutes)
   • Speed: 74880 (yes: this is an unusual baud rate, not a typo)
   Save this profile as "ESP-COM4-74880"
3. Open this connection by pressing the "Open" button: you should see a black window
4. Now press the RST (= RESET)-button on the NodeMCU, you should see a text similar to this:
   Code: Select all ets Jan  8 2013,rst cause:2, boot mode:(3,6)

load 0x4010f000, len 1384, room 16
tail 8
chksum 0x2d
csum 0x2d
v00000000
~ld
   If you get messages like "chksum err" (or "csum err"), your previous flash attempt failed and you'll have to reflash your NodeMCU with the correct firmware and settings and return to step 3 above.
5. When you're getting a message like above (thus NO "csum err" lines), you *should* be able to use the firmware you've flashed.
6. Create another profile in PuTTY with the settings:
   • Connection type: Serial
   • Serial line: [YOUR COMPORT] eg. "COM4" (without the qoutes)
   • Speed: 115200
   Save this profile as "ESP-COM4-115200"
7. Open the connection by pressing the "Open"-button: you should see a black window with a green cursor.
8. Now press (without making a typing error!) the letters "AT" (no quotes) followed by [CTRL]+M and [CTRL]+J ([CTRL] is, of course, the CTRL-key on your keyboard)
   If you do make an error while typing, don't back space, but perform a [CTRL]-M & [CTRL+J] (you'll get a message saying "ERROR") and try again.
9. You should be greeted with the message "OK"if the command could be processed
10. Try other AT-commands, like the ones in this list.

If you're stuck, please let us know and be as detailed as possible (ie. don't just say: "It doesn't work").