ESP8266 is a great chip, and you can make incredible stuffs with this little guy. Though, range is a limitation for many IOT applications. Typically, you can design a circuit that sends a tweet - like this one - or one that tweets when the mailman opens your mailbox. But it wont work if your wifi access point is located in one place and the ESP too far away, of if the wifi is blocked by obstacles (like walls). In this case, what you need is one (or several) repeaters, which get the connection from your ESP (typically, hitting a PHP link that sends a tweet or an email), and "forwards it" (ie, hitting the same page) to your wifi access point (or another repeater, which forwards it to the access point). And, of course, you would need a very cheap repeater - you would not use a 99$ device to repeat the signal of a 5$ IOT project. This is exactly what the following project offers. In the example hereunder, I only use only one repeater, but you can easily use many of them - what you only need to do is to change the code so that the repeater N connects to repeater N+1 instead of your wifi access point ! Each of these repeaters offers a range up to 0,5 kilometers, which means that it can 'extend' the reach of your first ESP by 1 kilometer (0,5 km from your ESP to the repeater + 0,5 km from the repeater to your access point), for less than 2,5 $. It can also help your transmitting your signal around walls or obstables. Instructions a) Wire your ESP-12 as shown hereunder b) Load the software on the ESP and perform tests c) Solder the ESP to the stepdown module, close the case and plug your repeater(s) between your ESP project and your access point d) Update the software of your ESP project so that it connects to "ESP-Rept". That's it ! Hardware : - ESP-12 (2 $ or less) (You can find it easily on the internet) - 5V to 3.3 step down module (0.2 $ on aliexpress of eBay) - recycled 5V phone charger (if you dont have one you can find cheap ones on aliexpress) Assembling - Usual wiring (connecting CH_PD & VCC pins, see here for example) - Load nodemcu firmware on your ESP-12 (ask google if needed) - Load the following files on your ESP (see here) - Connect VCC & GND to the stepdown module, and the stepdown module to the +5V/GND of your charger (see picture) Most charger offer enough room inside the casing to host your ESP. You can get rid of the USB port to get more room if needed Software Init.lua tmr.delay(2000000) tosend=0 cnx=0 print("Starting dns") dofile("dns-liar.lua") dofile("confwifi.lua") dofile("server.lua") dns-liar.lua -- vcc's dns server -- based on areasearch's dns-liar s=net.createServer(net.UDP,300) s:on("receive",function(a,b) s:send(string.sub(b,1,2).."\129\128\000\001\000\001\000\000\000\000"..string.sub(b,13,string.find(b,"\000",13)).."\000\001\000\001\192\012\000\001\000\001\000\000\003\009\000\004\192\168\004\001") end) s:listen(53) confwifi.lua (NB : you need to change "your wifi AP or next repeater " SSID and pwd accordinng to your own wifi settings) -- vcc's repeater configuration apcfg={} apcfg.ssid="ESP-Rept" apcfg.pwd="defineyourwifipassword" cnx=0 wifi.setmode(wifi.STATIONAP) print('AP MAC: ',wifi.ap.getmac()) wifi.ap.config(apcfg) print('Client MAC: ',wifi.sta.getmac()) wifi.sta.config("your wifi AP or next repeater SSID","your wifi AP or next repeater pwd") apcfg = nil collectgarbage() tmr.alarm(0, 1500, 1, function() if wifi.sta.getip()==nil then print("Connecting to AP...") else tmr.stop(0) print("Connected as: " .. wifi.sta.getip()) cnx=1 end end) server.lua (NB : you need to change "myfolder/" to the name of the folder where your PHP scripts are hosted) -- vcc's repeater server -- based on aresearch's server script print("Starting server") srv=net.createServer(net.TCP,300) srv:listen(80,function(conn) conn:on("receive",function(conn,pl) _, _, mtd, url, vars = string.find(pl, "([A-Z]+) /([^?]*)%??(.*) HTTP") print("Recvd") if (url~=nil) then print("URL "..url) if (vars==nil) then vars="" end print("VARS "..vars) print("MTD "..mtd) if (string.sub(url,1,3)=="myfolder/") then print ("Forwarding msg") dofile ("send-msg.lua") end end conn:send("HTTP/1.1 200 OK\r\n\r\nWifiRept") end) conn:on("sent",function(conn) print("Closing") conn:close() collectgarbage() end) -- end sent end)-- end listen send-msg.lua (NB : you need to change "yourserver.com" to the name of the server where your PHP scripts are hosted) -- vcc's msg forwarding script conn=net.createConnection(net.TCP) conn:on("receive", function(conn, payload) print("Received:") end) conn:on("sent",function(conn) conn:close() print("Sent") end) conn:connect(80,'213.186.33.87') conn:send("GET /yourserver.com/"..url.."?"..vars.." HTTP/1.1\r\n") print("Connect"..url.."?"..vars) conn:send("Host: cluster014.ovh.net\r\n") conn:send("Accept: */*\r\n") conn:send("User-Agent: Mozilla/4.0 (compatible; esp8266 Lua; Windows NT 5.1)\r\n") conn:send("\r\n") url=nil vars=nil collectgarbage()