Arduino NodeMCU and esp8266 – Janoš Šikloši

I recently got esp8266 cheap wifi module. I had idea to use it with arduino and existing project that was using CmdMessenger library to comunicate over serial/usb port. After playing with esp8266 I found nice solution to how to replace serial cable. I installed NodeMCU on esp8266 and installed on it two scripts

wifi.setmode(wifi.STATION)
wifi.sta.config("ssid","password")
dofile("tel.lua")
tmr.alarm(0, 5000, 0, function() 
uart.write(0,"\n\r5,")
uart.write(0,wifi.sta.getip())
uart.write(0,";")
 end )

wifi.setmode(wifi.STATION)

wifi.sta.config("ssid","password")

dofile("tel.lua")

tmr.alarm(0, 5000, 0, function()

uart.write(0,"\n\r5,")

uart.write(0,wifi.sta.getip())

uart.write(0,";")

end )

and

s=net.createServer(net.TCP,180) 
s:listen(1001,function(c) 
    function s_output(str) 
      if(c~=nil) 
        then c:send(str) 
      end 
    end 
    node.output(s_output, 0)   
    c:on("receive",function(c,l) 
      node.input(l)           
    end) 
    c:on("disconnection",function(c) 
      node.output(nil)        
    end) 
    print("Connected\r\n")
end)

s=net.createServer(net.TCP,180)

s:listen(1001,function(c)

function s_output(str)

if(c~=nil)

then c:send(str)

end

node.output(s_output, 0)

c:on("receive",function(c,l)

node.input(l)

end)

c:on("disconnection",function(c)

node.output(nil)

end)

print("Connected\r\n")

end)

when booting telnet server is opened on port 1001 and ip address is sent to arduino (“5,192.168.0.10;”) so that it can be printed on LCD. When connected from computer to esp8266 using python (terminal on 1001) i send for example uart.write(0,”1,255;”) and “1,255;” is sent to arduino and when arduino send something back to PC i send it like “print”123″” and 123 is printed on terminal/sent to python.

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