NodeMcu

A lua based firmware for wifi-soc esp8266

version 0.9.2 build 2014-12-11

Change log

2014-12-09

increased the number of alarm in tmr module, now it has 7 alarm.

2014-12-08

add uart.setup(), uart.write() api.

Summary

Easy to access wireless router
Based on Lua 5.1.4
Event-Drive programming preferred.
Build-in file, timer, pwm, i2c, 1-wire, net, gpio, wifi, adc, uart and system api.
GPIO pin re-mapped, use the index to access gpio, i2c, pwm.
GPIO Map Table:

IO index	ESP8266 pin	IO index	ESP8266 pin
0	GPIO12	8	GPIO0
1	GPIO13	9	GPIO2
2	GPIO14	10	GPIO4
3	GPIO15	11	GPIO5
4	GPIO3
5	GPIO1
6	GPIO9
7	GPIO10

Flash the firmware

nodemcu_512k.bin: 0x00000

for most esp8266 modules, just pull GPIO0 down and restart.

You can use the nodemcu-flasher to burn the firmware.

Connect the hardware in serial

braudrate:9600

Start play

Connect to your ap

    print(wifi.sta.getip())
    --0.0.0.0
    wifi.setmode(wifi.STATION)
    wifi.sta.config("SSID","password")
    print(wifi.sta.getip())
    --192.168.18.110

Manipulate hardware like a arduino

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

Write network application in nodejs style

    -- 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")

Or a simple 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)

Do something shining

  function led(r,g,b) 
    pwm.setduty(0,r) 
    pwm.setduty(1,g) 
    pwm.setduty(2,b) 
  end
  pwm.setup(0,500,512) 
  pwm.setup(1,500,512) 
  pwm.setup(2,500,512)
  pwm.start(0) 
  pwm.start(1) 
  pwm.start(2)
  led(512,0,0) -- red
  led(0,0,512) -- blue

And blink it

  lighton=0
  tmr.alarm(1,1000,1,function()
    if lighton==0 then 
      lighton=1 
      led(512,512,512) 
    else 
      lighton=0 
      led(0,0,0) 
    end 
  end)

If you want to run something when system started

  --init.lua will be excuted
  file.open("init.lua","w")
  file.writeline([[print("Hello, do this at the beginning.")]])
  file.close()
  node.restart()  -- this will restart the module.

With below code, you can telnet to your esp8266 now

    -- a simple telnet server
    s=net.createServer(net.TCP,180) 
    s:listen(2323,function(c) 
       function s_output(str) 
          if(c~=nil) 
             then c:send(str) 
          end 
       end 
       node.output(s_output, 0)   -- re-direct output to function s_ouput.
       c:on("receive",function(c,l) 
          node.input(l)           -- works like pcall(loadstring(l)) but support multiple separate line
       end) 
       c:on("disconnection",function(c) 
          node.output(nil)        -- un-regist the redirect output function, output goes to serial
       end) 
       print("Welcome to NodeMcu world.")
    end)

Use DS18B20 module extends your esp8266

    -- read temperature with DS18B20
    t=require("ds18b20")
    t.setup(9)
    addrs=t.addrs()
    -- Total DS18B20 numbers, assume it is 2
    print(table.getn(addrs))
    -- The first DS18B20
    print(t.read(addrs[1],t.C))
    print(t.read(addrs[1],t.F))
    print(t.read(addrs[1],t.K))
    -- The second DS18B20
    print(t.read(addrs[2],t.C))
    print(t.read(addrs[2],t.F))
    print(t.read(addrs[2],t.K))
    -- Just read
    print(t.read())
    -- Just read as centigrade
    print(t.read(nil,t.C))
    -- Don't forget to release it after use
    t = nil
    package.loaded["ds18b20"]=nil

Check this out

Tencent QQ group: 309957875

nodemcu wiki

nodemcu.com