ESP8266 Community Forum

- Sat Apr 18, 2015 7:27 am #14900 I am playing around with an ESP8266-12, but have some issues getting it to work properly i.e.
1) basic hardware setup for flashing and operation (I believe I got this covered, though I am not sure, since the different guides/tutorials are always a little different)
2) AT commands for the factory firmware not always returning a response or "invalid"
3) error after loading NodeMCU (0.9.5_20150318), MEM CHECK FAIL!!! Fatal exception (0):

I believe the hardware setup is finally correct, but I have some problems getting some proper AT response though. I ended up connecting it like this diagram in this post viewtopic.php?f=13&t=1672#p10027. At baud rate 115200 I was able to get the best response, but most of the time it would return Ai-Thinker followed by "invalid", at other baud rates it returned gibberish. Then suddenly it worked, I would get proper response, I could find connect to the AP from my phone and computer, but after a reboot it did not work again.

I decided to load the latest NodeMCU. It successfully uploaded the firmware but after reboot it it replies

Code: Select allMEM CHECK FAIL!!!
Fatal exception (0):
epc1=0x4022169b, epc2=0x00000000, epc3=0x00000000, excvaddr=0x00000000, depc=0x00000000
Fatal exception (0):
epc1=0x4021086e, epc2=0x00000000, epc3=0x00000000, excvaddr=0x00000000, depc=0x00000000
Fatal exception (0):
...
...
And many more lines

I am most likely doing something very wrong, since I am totally new to ESP8266, but cannot pinpoint where I am failing.

My current hardware setup consists of:

• OS X and Windows 8.1
• PL2303HX USB to TTL http://www.dx.com/p/pl2303hx-usb-to-ttl ... TJJmc4azT0
• USB2.0 To TTL 6Pin CH340G http://www.aliexpress.com/item/USB2-0-T ... 47221.html
• ESP8266-12 (+ another -12 and -07 I will test out later when I get a better breakout board)
• External power supply (1A, 3.3V) or from the USB to TTL module, had the best result with powering from the USB to TTL module
• Arduino 1.6.3 for serial communication

Edit
I got this one to work AI-v0.9.5.0 AT Firmware.bin powered from the PL2303HX USB to TTL at 9600.
https://drive.google.com/folderview?id= ... JmNU0#list

But still no luck with NodeMCU.

Robot enthusiast | Indie developer | Enjoys life

- Wed Apr 22, 2015 2:04 pm #15307 A small update.

I tried one of the other ESP8266 I bought, this time ESP-07 and it works just great with NodeMCU

Not sure why the ESP-12 did not work, waiting for another one to test.

Robot enthusiast | Indie developer | Enjoys life

- Sun May 31, 2015 7:41 am #19029 Having the same thing here, the esp-01 worked fine.
But I just can't get this thing to work ...
Did you have any success after ?

- Sun May 31, 2015 3:41 pm #19062 I have the same problem. Any idea?