Required Tools

Installing esptool

$ git clone https://github.com/themadinventor/esptool.git
$ cd esptool
$ python setup.py install -local

NodeMCU Uploader

This tool uploads the Lua files. Requires that the device is runnig the Lua firmware.

$ git clone https://github.com/kmpm/nodemcu-uploader.git
$ cd nodemcu-uploader

https://github.com/nodemcu/nodemcu-firmware

Installing Lua Interpreter

1. Download a release from https://github.com/nodemcu/nodemcu-firmware/releases

2. Check that you have a connection to the board:

   $ esptool.py read_mac Connecting... MAC: 18:fe:34:06:59:a5

3. Upload firmware

   $ esptool.py write_flash 0x0 nodemcu_integer_0.9.6-dev_20150704.bin Connecting... Erasing flash... Wrote 450560 bytes at 0x00000000 in 43.8 seconds (82.4 kbit/s)...

   Leaving...

4. Now start talking!

Talking to the Lua firmware

On unix Screen is a useful tool to talk to serial ports. Usage:

$ screen <device> <baud rate>

$ screen /dev/ttyUSB0 9600

After starting screen and pressing reset you should get some output similar to this:

<��������������x�

NodeMCU 0.9.6 build 20150704  powered by Lua 5.1.4
lua: cannot open init.lua
>

The first garbage output is expected and is from the bootloader trying to autodetect the baud rate.

Installing eLua cross-compiler (optional)

git clone https://github.com/elua/elua.git

First Code

Open screen and paste this code:

-- Get the current IP
ip = wifi.sta.getip()
-- This should print nil
print(ip)

-- Configure the device
wifi.setmode(wifi.STATION)
wifi.sta.config("...", "...")

-- Now check that the IP is assigned. It might take some time so try again.
ip = wifi.sta.getip()
print(ip)

Building a new Lua firmware

Build and install the compiler and SDK

$ git clone --recursive https://github.com/pfalcon/esp-open-sdk.git
$ cd esp-open-sdk
$ make STANDALONE=n
.. wait a while ..

Add the compiler to your $PATH (see output)

$ cd ..
$ git clone https://github.com/nodemcu/nodemcu-firmware
$ cd nodemcu-firmware
$ make

References

• Lua API * *
• http://blog.3mdeb.com/2015/01/25/esp-12-upgrade-to-esp-iot-sdk-v0-dot-9-5-using-esp-open-sdk-toolchain/