# 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
1. Check that you have a connection to the board:

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

1. 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...

1. 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](https://github.com/nodemcu/nodemcu-firmware/wiki/nodemcu_api_en)
 *
 *
 * http://blog.3mdeb.com/2015/01/25/esp-12-upgrade-to-esp-iot-sdk-v0-dot-9-5-using-esp-open-sdk-toolchain/