NodeMCU

NodeMCU是一个开源的物联网平台。 它使用Lua脚本语言编程开源项目,底层使用ESP8266 sdk 0.9.5版本。该平台使用了很多开源项目, 例如 lua-cjson, spiffs. NodeMCU包含了可以运行在 esp8266 Wi-Fi SoC芯片之上的固件,以及基于ESP-12模组的硬件。

History
NodeMCU is started after ESP8266 come out. In December 30, 2013, Espressif systems begin production of ESP8266. ESP8266 is an Wi-Fi SoC and integrated with LX106 core, widely used in IoT applications(See related projects NodeMCU project started. And then more and more developers from ESP8266 opensource community join in NodeMCU developer team. On 1 Dec 2014, Huang R commit the gerber file of an ESP8266 board, then NodeMCU project have the first open-hardware which named devkit 1.0, thus NodeMCU is not only a firmware, it becomes a platform. In 31 Dec 2014, Tuan PM port MQTT client library from Contiki to ESP8266 SoC platform, and commit to NodeMCU project, then NodeMCU can support MQTT IoT protocol, using Lua access MQTT broker, it is an important update of firmware. Another important update is in 30 Jan 2015, Devsaurus port u8glib to NodeMCU project, and NodeMCU can drive LCD, Screen, OLED, even VGA display module easily.

Pins腳
NodeMCU 提供對 GPIO（通用輸入/輸出）的存取控制，並且引腳映射表是 API 文件的一部分。

[*] D0 (GPIO16) 只能用於GPIO讀/寫。它不支援open-drain/interrupt/PWM/I²C 或 1-Wire。

硬體連接
如果使用 NodeMCU devkit, 只需要安裝 CH340G 驅動程式。

特别的，如果你想编译/构建自己的固件，需要注意以下烧写地址：
0x00000.bin: 0x00000
0x10000.bin: 0x10000

注意，在烧写之后，最好执行 file.format()

程式举例
连接Wi-Fi热点
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
如同arduino般操作硬体
pin = 1
gpio.mode(pin,gpio.OUTPUT)
gpio.write(pin,gpio.HIGH)
print(gpio.read(pin))
使用 nodejs 风格网络编程
-- 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")
简易的HTTP伺服器
-- A simple http server
srv=net.createServer(net.TCP)
srv:listen(80,function(conn)
conn:on("receive",function(conn,payload)
print(payload)
conn:send(" Hello, NodeMcu.
")
end)
conn:on("sent",function(conn) conn:close() end)
end)
连接 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 客户端与伺服器
-- 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")

引用文献