The use of the ESP8266 in the world of IoT

User avatar
By Ipposnif
#91718 Hi, I had this module ESP8266 ESP-12F watching at me from my desk for months. Today I finally decided to wire it to my Arduino UNO as an external AT modem.
Correct voltage, enough current, resistors dividers for RX pin, all pull-up and pull-down wired with attention.
Nothing! It is not AT-friendly at all.
I wrongly supposed that it comes in default with AT firmware, and there is no need to flash anything to use it as a simple modem.
After a bit of a hassle I managed to connect to it (using AltSoftSerial) and get this answer:

NodeMCU 0.9.5 build 20150318 powered by Lua 5.1.4

I've bought this module from Mouser (
I swear I have never flashed anything to it, I have still not wired the two buttons or the circuit logic to do this.
Please help me to understand what is wrong. I'm really new to the ESP world, forgive me if this is a dummy question:

Is it normal that I find the NodeMCU firmware on and module that is not soldered to a NodeMCU board?
User avatar
By schufti
#91726 at least you managed to "get in contact" with the module, other beginners fail earlier.
different users, different expectations... there is no "standard" firmware. The first batch of esp-01 came with AT fw, obviously a quick "mock-up" from espressif to show versatility of its chip; of little use nowaday with esp8266 support in arduino ide.
User avatar
By davydnorris
#91731 Depending on the module you purchased it'll be flashed with some default firmware.

The Lolin NodeMCU units are flashed with... you guessed it... NodeMCU, which is the runtime for the Lua programming language.

I've found that only the Espressif made and shipped ones are flashed with AT firmware by default, everything else has been a mix. Some have NodeMCU, some have AT, some have nothing.