First impressions LoLin NodeMCU V3

The LoLin NodeMCU v3 is a breadboard compatible development board combining the popular ESP8266 Wifi module with an USB connector for power and serial programming.

LoLin NodeMCU v3

LoLon NodeMCUv3 pinout

 

Connecting to the serial port

Connect the LoLin NodeMCU to a PC via the USB serial port and use serial console software at 115200 baud to connect e.g. PuTTY or the Arduino IDE serial monitor.

Press reset and the LoLin NodeMCU v3 will display some garbage (this is a boot message which uses a different baud rate during boot) followed by 'Ready' once booted, depending on the firmware installed. 

Firmware

There are several different 'standard' firmwares available for ESP2866 based devices which can be confusing.

Two of which are the AI-thinker firmware which supports AT commands and the NodeMCU firmware which includes a LUA interpreter.     

Out of the box my NodeMCU device did not respond to any AT commands but did provide an wi-fi Access Point and DHCP service for connecting wireless devices but offered no open ports. Possibly it is running the NodeMCU firmware?

Serial port output on first boot

Flashing with ai-thinker-0.9.5.2-115200.bin firmware

ESP38266 devices can be flashed with a different firmware. To flash with the ai-thinker firmware

1) Download the NodeMCU Flasher Master software
2) Download the ai-thinker firmware
3) Start nodemcu-flasher-master > Win64 > Release > ESP8266Flasher software
4) Select the firmware to flash. Config > first wheel > select ai-thinker firmware
5) Flash the ESP8266. Operation > Flash
6) Once complete. Reset the LoLin

Running the ai-thinker firmware the ESP8266 now responds to AT commands on the serial port. 

Serial port output after flashiing with AI-thinker firmware

 

The following website is a good source of supported AT commands.

A port scan of the newly flashed firmware revealed no open ports. Running the commands AT+CIPMUX=1 and  AT+CIPSERVER=1,80 configures a web server and the serial output will show debug details of received requests. The web server is not very useful as it servers no web-pages and you can't configure the device via it.

Using the Arduino IDE

The best way to use the device is to program it with your own programs (sketches) using the Arduino IDE and ESP8266 board managers.


If you receive the following error message when flashing the board ensure NodeMCU 0.9 (ESP-12 Module) is selected in Tools > Board.  The Arduino IDE uses the selected board type to perform a board specific reset procuedure when flashing.

warning: espcomm_sync failed
error: espcomm_open failed
error: espcomm_upload_mem failed
error: espcomm_upload_mem failed