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[solved] Can't communicate with my ESP-12 after flashing

PostPosted: Mon Apr 13, 2015 3:48 pm
by churchill
Hello,
I just got my first ESP8266, and played yesterday with the AT commands.
Today I've flashed the NodeMCU firmware following the instructions on Yoann's Blog. In first I got some trouble (Failled to connect) with esptool (I'm on Debian), but after reading Linux geek’s scratchpad all was OK (need to power ESP only just before flashing).
So finally, I flashed NodeMCU
Code: Select allesptool.py --baud 9600 write_flash 0x00000 app/.output/eagle/debug/image/eagle.app.v6.out-0x00000.bin 0x10000 app/.output/eagle/debug/image/eagle.app.v6.out-0x10000.bin
Connecting...
Erasing flash...
Writing at 0x0000c400... (100 %)
Erasing flash...
Writing at 0x00068800... (100 %)

But now, I can't connect to the ESP. This is what I got when I launch miniterm and power the ESP12 :
Code: Select allminiterm.py /dev/ttyUSB0 9600
--- Miniterm on /dev/ttyUSB0: 9600,8,N,1 ---
--- Quit: Ctrl+]  |  Menu: Ctrl+T | Help: Ctrl+T followed by Ctrl+H ---
0��8��

Nothing more appends :-(
What I'm doing wrong ?

Re: Can't communicate with my ESP-12 after flashing NodeMCU

PostPosted: Mon Apr 13, 2015 4:03 pm
by churchill
After a lot of research I posted this topic, like a bootle in the sea :
churchill wrote:But now, I can't connect to the ESP. This is what I got when I launch miniterm and power the ESP12 :
Code: Select allminiterm.py /dev/ttyUSB0 9600
--- Miniterm on /dev/ttyUSB0: 9600,8,N,1 ---
--- Quit: Ctrl+]  |  Menu: Ctrl+T | Help: Ctrl+T followed by Ctrl+H ---
0��8��

Nothing more appends :-(
What I'm doing wrong ?


...and some minutes later (!) I found the solution.

So the problem was a wrong baudrate. I don't know what baudrate I have to use, but I read in this post if I connect GPIO15 to ground, the baudrate is fixed to 9600. So, now I can use miniter :
Code: Select all$ miniterm.py /dev/ttyUSB0 9600
--- Miniterm on /dev/ttyUSB0: 9600,8,N,1 ---
--- Quit: Ctrl+]  |  Menu: Ctrl+T | Help: Ctrl+T followed by Ctrl+H ---
<������(�����(�.,������

NodeMCU 0.9.5 build 20150318  powered by Lua 5.1.4
lua: cannot open init.lua
>

Re: [solved] Can't communicate with my ESP-12 after flashing

PostPosted: Wed Apr 29, 2015 5:19 am
by Simon
I have had the exact same problem, tried flashing two ESP-12 with NodeMCU, but have not been able to communicate with them after flashing. I have had GPIO15 grounded all the time, but no matter what baud rate I use, I get no response from the unit. They work fine if I flash them with AT 0.9.5 firmware.

What version of NodeMCU firmware did you use?

Re: [solved] Can't communicate with my ESP-12 after flashing

PostPosted: Thu Apr 30, 2015 10:25 am
by jumjum123
I had the same problem with ESP-12. Based on some other info in this forum, found that baud rate was running at 74880. Using putty checked with this baudrate and the board was still alive.
All of these hints with IO15 and a lot of other hints did not help.
At the end, I tried an old version of AT-based firmware. This worked fine, after a lot of stopped flashings.
Next tried to upload nodemcu v0.95 which worked on first try, and next flashed 0.96 which also worked fine.
Not sure what helped at the end, all together I spent about 2 days.
BTW, never had similiar problems with ESP-01.
Regards from Krefeld
Jürgen