NodeMCU

NodeMCU

NodeMCU DEVKIT 1.0 NodeMCU DEVKIT 1.0 BOTTOM
Developer	ESP8266 Opensource Community
Type	Single-board microcontroller
Operating system	XTOS
CPU	ESP8266[1](LX106[2])
Memory	20kBytes
Storage	4MBytes[3]
Power	USB
Website	http://www.nodemcu.com

NodeMCU is an opensource IoT platform.^[4][5] It uses the Lua scripting language. It is based on the eLua project, and builded on ESP8266 sdk 0.9.5. It uses many open source projects, such as lua-cjson,^[6] and spiffs.^[7] It includes firmware which runs on esp8266 Wi-Fi SoC, and hardware^[8] which is based on ESP-12 module.

History

NodeMCU was created shortly after the ESP8266 came out. In December 30, 2013, Espressif systems began production of the ESP8266.^[9] The ESP8266 is a Wi-Fi SoC integrated with an LX106 core, widely used in IoT applications (See related projects^[10][11][12]). In 13 Oct 2014, Hong committed the first file of nodemcu-firmware to github,^[13] and the NodeMCU project started. From then on more and more developers from ESP8266 opensource community joined the NodeMCU developer team. On 1 Dec 2014, Huang R committed the gerber file of an ESP8266 board, then the NodeMCU project have the first open-hardware which named devkit 1.0,^[14] thus NodeMCU was not only a firmware anymore, but also a platform. In 31 Dec 2014, Tuan PM ported MQTT client library from Contiki to the ESP8266 SoC platform,^[15] and committed to NodeMCU project, then NodeMCU was able to support the MQTT IoT protocol, using Lua to access the MQTT broker, it is an important update of firmware. Another important update was on 30 Jan 2015, when Devsaurus ported the u8glib^[16] to NodeMCU project,^[17] enabling NodeMCU to easily drive LCD, Screen, OLED, even VGA displays.

Related projects

The Button

The Button is a Wi-Fi connected push button designed by Peter Jennings.^[10] The button is one of those project that is easy to make and useful in more ways than we can count. The idea is simple. Press the button and a connection is made to a web server which will perform the desired task, such as panic Button, doorbell, Booty Call, etc.

NodeUSB

NodeUSB is an open IoT platform for coders, hackers, makers, programmers and everyone else. Kit is based on (ESP8266), size is similar to USB driver. Easy to code(Lua), easy to develop(Web IDE), easy to expand by USB. Plug-n-Play, Production ready, prototype very close to end product, using NodeMCU firmware.^[11] It have a development kit and Web IDE, and Lua script package completed .

ijWatch

ijWatch is an open-hardware and open-source Wi-Fi smartwatch, using OLED screen and running NodeMCU firmware.^[12] As far as we can tell the first real smartwatch, the first without Bluetooth and also the first opensource smartwatch without an Arduino.

Before using

Flash the firmware

nodemcu_latest.bin: 0x00000
for most esp8266 modules, just pull GPIO0 down and restart.
You can use the nodemcu-flasher to burn the firmware.

Or, if you build your own bin from source code.
0x00000.bin: 0x00000
0x10000.bin: 0x10000

Better run file.format() after flash

Connect the hardware in serial

If using NodeMCU devkit, just install CH340G driver, and plug it in your PC using a micro-usb cable. Then set baudrate to 9600, open the serial port. If using normal esp8266 module, a usb-ttl bridge required.

Start play

Connect to an AP

    ip = wifi.sta.getip()
    print(ip)
    --nil
    wifi.setmode(wifi.STATION)
    wifi.sta.config("SSID","password")
    ip = wifi.sta.getip()
    print(ip)
    --192.168.18.110

Control GPIO

    pin = 1
    gpio.mode(pin,gpio.OUTPUT)
    gpio.write(pin,gpio.HIGH)
    print(gpio.read(pin))

HTTP request

    -- A simple http client
    conn=net.createConnection(net.TCP, 0)
    conn:on("receive", function(conn, payload) print(payload) end )
    conn:connect(80,"115.239.210.27")
    conn:send("GET / HTTP/1.1\r\nHost: www.baidu.com\r\n"
        .."Connection: keep-alive\r\nAccept: */*\r\n\r\n")

HTTP server

    -- A simple http server
    srv=net.createServer(net.TCP)
    srv:listen(80,function(conn)
      conn:on("receive",function(conn,payload)
        print(payload)
        conn:send("<h1> Hello, NodeMcu.</h1>")
      end)
      conn:on("sent",function(conn) conn:close() end)
    end)

Connect to MQTT Broker

-- init mqtt client with keepalive timer 120sec
m = mqtt.Client("clientid", 120, "user", "password")
 
-- setup Last Will and Testament (optional)
-- Broker will publish a message with qos = 0, retain = 0, data = "offline"
-- to topic "/lwt" if client don't send keepalive packet
m:lwt("/lwt", "offline", 0, 0)
 
m:on("connect", function(con) print ("connected") end)
m:on("offline", function(con) print ("offline") end)
 
-- on publish message receive event
m:on("message", function(conn, topic, data)
  print(topic .. ":" )
  if data ~= nil then
    print(data)
  end
end)
 
-- for secure: m:connect("192.168.11.118", 1880, 1)
m:connect("192.168.11.118", 1880, 0, function(conn) print("connected") end)
 
-- subscribe topic with qos = 0
m:subscribe("/topic",0, function(conn) print("subscribe success") end)
-- or subscribe multiple topic (topic/0, qos = 0; topic/1, qos = 1; topic2 , qos = 2)
-- m:subscribe({["topic/0"]=0,["topic/1"]=1,topic2=2}, function(conn) print("subscribe success") end)
-- publish a message with data = hello, QoS = 0, retain = 0
m:publish("/topic","hello",0,0, function(conn) print("sent") end)
 
m:close();
-- you can call m:connect again

UDP client and server

-- a udp server
s=net.createServer(net.UDP)
s:on("receive",function(s,c) print(c) end)
s:listen(5683)
 
-- a udp client
cu=net.createConnection(net.UDP)
cu:on("receive",function(cu,c) print(c) end)
cu:connect(5683,"192.168.18.101")
cu:send("hello")

References

External links