ESP8266 Community Forum

I have a simple program flashed into my NodeMCU ESP8266 12E which drives 4 relays. I seem to be loosing connection to WiFi during the night, and I want to gather information on what is going on. If I power the device off then on, my connection is good again.

If I connect my windows laptop to the NodeMCU and open Arduino IDE's serial port, I was expecting that I could issue an AT command, but nothing shows up in the serial monitor. I do get output into the serial monitor after the upload of the program, or if I hit the reset button on the NodeMCU. I know I am set to the correct baud rate and I have "Both NL and CR" selected in the Line Editing drop down. Do I need to install some firmware to support the AT command? Or should it do it natively?

I have development chips from MakerFocus. I opened a new chip and flashed the blink sketch into it. I found that if I hit the reset button on NodeMCU and set the baud rate to 74880, I get the following text :

ets Jan 8 2013, rst, cause:2, boot mode:(3,6)

load 0x4010f000, len 1384, room 16
tail 8
chksum 0x2d
csum 0x2d
v09f0c112
~1d

Support for the AT commands were in the firmware you overwrote with your program; you need to reinstall the "AT firmware" (and lose your program).

What eduperez says...
You have to build in debug code into your sketch.

Often made mistakes in (Arduino - ESP8266 core) code is starving the WiFi core (long delays/while loops without yield() ), resulting in watchdog resets and not correctly dealing with connection losses.

eduperez wrote:Support for the AT commands were in the firmware you overwrote with your program; you need to reinstall the "AT firmware" (and lose your program).

I first tried the "AT" command on a brand new development board I just opened. I then tried loading a program and trying the "AT" command again as a test. Speaking of firmware, I played with esplorer to install firmware, but is there a easy way to check firmware on new NodeMCU ESP8266 E12 development chips you just opened up?