ESP8266 Community Forum

- Sun Mar 13, 2016 9:15 pm #43062 Hello everyone, need help for my problem. I'm still beginner so be easy on me.

At first, I could do AT command but after flashing the code from here:
https://learn.sparkfun.com/tutorials/es ... web-server

I can't do it anymore, I have tried many things but until now It still can't do AT command. However the esp-01 still can do flashing. Here the flashing I do (still the same code as above) :


I tried flashing firmware using the esptool.py and esp8266 flasher, it worked but still can't do AT, if I use the esp8266 flash download tool, it seems failed, here the flashing:


The connection can be read in terminal only in ~74880 baud rate which in other place said that it suppose to change to 9600 or 115200 from 74880 after restart/reset process. But I have tried changing baud rate but it don't work. This is the result of serial connection with the flash code still in there on coolterm(baudrate 74880):

if there isn't flash code, it only show (after I tried flashing firmware using esptool/esp flasher, though I don't know if the code is erased or not but assume that it is erased since the name of wifi connection gone):
ets Jan 8 2013,rst cause:2, boot mode:(3,6)

I don't know if the hardware connection is wrong or not since at first it worked, and I followed the usual connection. Haven't tried to play many things around hardware connection, the only thing I tried is gpio2, if ground it would show fatal exception, and if high it would not do anything even rst couldn't be done so I left it floating.

The other thing I haven't do is trying NodeMCU flasher, maybe I will try it later as last resort.

- Mon Mar 14, 2016 1:17 am #43072 Is gpio 0 grounded?

What version of the AT firmware are you trying to use.

Is there a reason to use the AT fimware and not program the device with the arduino environment?

Serial terminal in the chrome browser see https://serialTerminal.com

http://esp8266basic.com
A BASIC interpreter for your ESP

Working now on Autodrop3d. A 3d printer with automatic part ejection system. https://autodrop3d.com

- Mon Mar 14, 2016 10:16 am #43093 1.Nope, after flashing I turn off the board then left gpio0 floating then turn it on again. I only connect it to the ground for flashing. Anyway, don't you see the image or the boot mode status of the board from coolterm? it's on mode 3 which is boot up from flash.

2.I tried v0.9.2.2 and v0.9.5.2 which is still fail to do AT command (it succes in flashing the firmware). Second, I tried with the same way in this web:
http://www.allaboutcircuits.com/project ... fi-module/

but as you can see, the esp flash download didn't work and I tried it using the esptool.py using the same bin file used as the web above and still fail to do AT command.

3. No, there is no reason, although when I build it as a client and using arduino to control it then I may need it. Since I haven't study further about the program I can't say much in this. Anyway, I want to do AT command because many info can be seen through AT so I can inspect it and I wanted to check if the serial connection is working or not, when the code is running.

I'm fine with arduino environment, but can you refer me to a place which tell complete wifiesp8266 function build in the arduino and not just code example which very few in explanation on esp mode, etc because I want to get the feel to control it more directly especially as client which usually controlled using serial connection through AT command. Although, I haven't tried to use read serial so if it works I will just use it instead AT command.

4. Well, my problem is still the same, why it can't do AT command, I doubt that because the firmware because even if the arduino didn't flash the AT firmware, I have tried flashing back to the AT firmware which have been tried by many other people and they work while I'm not.

Other info I haven't told:
- the flashing is good but when using esptool.py to read_flash it failed (invalid head of packet),
- erase_flash seems not working(it shown this may take a while but after that immediately exit the erase process but since after erasing it shown ets_main.c, I think it works)
- adding it with the failing on flashing using esp flash download, it's clearly there is something wrong but I don't know where.

- Tue Mar 15, 2016 12:41 am #43173 I faced a similar issue with 1M ESP-01 where flashing worked, but could never do AT commands. The combination below helped me. Pls give this a try:

ESP FLASH DOWNLOAD TOOL V2.3 (for flashing)
v1.1.1.1 AT Firmware.bin (This firmware will help you run AT commands)
ESPlorer v0.1 build 206 (To connect and run AT commands)