Use this forum to chat about hardware specific topics for the ESP8266 (peripherals, memory, clocks, JTAG, programming)

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By BayBayMan
#67258 I recently reflashed my esp8266 huzzah to respond to AT commands using the esp flasher tool. I flashed it with NONOS SDK V2.0.0, and it stated the flashing was successful. When trying to send AT commands through the Arduino serial monitor, there was no response. I made sure to have the correct settings, such as board, port, speed, etc.
Here are the results after flashing, and the settings used to flash the esp8266:


I used a FTDI console cable to connect the ESP8266 huzzah to one of my USB ports. The plan is to have AT firmware installed, so the Arduino can send AT commands to the esp. As of right now, this board hasn't responded to any AT commands, so I am thinking I am not sending AT commands correctly. I tried using Putty and Realterm, but I believe I don't know how to use it. Can someone help me out with these AT commands, or let me know if you see something wrong with what I'm doing?

I appreciate it!
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By QuickFix
#67293 First we need to know what the ESP says when you attach it to the FTDI and power it up.

  • Give the HUZZAH it's own 3.3V power supply (not the 3.3V provided by the FTDI-board), but do not power it on yet
  • Connect HUZZAH to FTDI: RX to TX and TX to RX, also connect the grounds of the HUZZAH, the HUZZAH-psu and the FTDI
  • Connect FTDI to USB of computer (it should get power from the computer: a red LED should lit if available)
  • See what port name the FTDI got
  • Open PuTTY with the following settings:
    • Connection type: Serial
    • Serial line: COM5 (fill in your port, of course)
    • Speed: 74880
    Tip: You might want to save these session settings for later use. :idea:
  • Press the "Open"-button, after which you will see a black window with a green cursor.
  • Now apply power to the HUZZAH
    or if you unintentionally did already gave it power (or want to try again from a later step):
  • Press and release the Reset-button on the HUZZAH
  • The blue LED on the ESP itself should briefly blink
  • Now watch your PuTTY console, what does it say?

  1. Absolutely nothing happens, the PuTTY-screen stays blank with a green cursor in the upper-left corner.
    Did the blue LED blink (briefly):
    • Yes: You probably have the RX and TX the wrong way around
    • No: You are probably not powering the HUZZAH correctly
  2. You get a similar text similar to this:
    Code: Select all ets Jan  8 2013,rst cause::1, boot mode:(3,7)

    load 0x4010f000, len 1384, room 16
    tail 8
    chksum 0xef
    csum 0xef
    csum err
    Note: the entry "csum err" is key here.
    When you get this message, it means there was an error flashing the ESP (there's a checksum error), likely caused by an improper power supply
  3. You get a similar text similar to this:
    Code: Select all ets Jan  8 2013,rst cause:2, boot mode:(3,6)

    load 0x40100000, len 1856, room 16
    tail 0
    chksum 0x63
    load 0x3ffe8000, len 776, room 8
    tail 0
    chksum 0x02
    load 0x3ffe8310, len 552, room 8
    tail 0
    chksum 0x79
    csum 0x79

    2nd boot version : 1.5
      SPI Speed      : 40MHz
      SPI Mode       : DIO
      SPI Flash Size & Map: 8Mbit(512KB+512KB)
    jump to run user1 @ 1000
    Note: "jump to run user1 @ 1000" is key here.
    If you get this output, it means the ESP can properly boot and *should* be able to accept AT-commands, though, most likely, at a different baud rate

What is the output you're getting?

If you get an output like #3, switch to the correct baud rate (probably 115200 baud)
Now enter the command AT followed by [CTRL]-M and [CTRL]-J: the AT should be echoed back when you type them and the ESP should response with OK.
Code: Select allAT


  • All AT-commands are in UPPER CASE
  • Do not use back space (or any other "Special" key on your keyboard)
    If you made a typing error, just send a <CR><LF> ([CTRL]-M and [CTRL]-J) and start over
User avatar
By WiredMaker
#81762 Hello,

I'm having the same problem. I'm sorry to reply to this old thread (should i make a new one?), but i followed the instructions given by QuickFix and after i press and release the Reset button on the HUZZAH, my PuTTY-screen displays the following:

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

I'm a new ESP user and i'm completely lost at this point. I have no experience with PuTTY and i would really appreciate if someone could explain to how to get AT commands working on my HUZZAH.

When i received the HUZZAH, it was preloaded with Lua. I used Arduino IDE 1.8.9 and uploaded a sketch and i think that replaced the Lua that was already on it. But shouldn't it still work? Or do i need to go back to Lua? I'm not sure what to do.

Extra info (maybe it can help to troubleshoot my problem):
I'm using a HUZZAH ESP8266 Breakout board that i purchased over a year ago. The info printed on the ESP housing says: 2AL3B-ESP-F which is different from the picture shown currently on the product page at Adafruit, where it shows: ESP8266MOD. I guess i'm using an old version of the ESP8266?? In that case, maybe i should update the firmware?? How to do that??