dynamically switch between wifi networks

问题:

I have two WiFi networks at home where I want to use my NodeMCU ESP8266 V1 to control several relays remotely over the web from anywhere in the world.To accomplish this I was thinking to test for WiFi connectivity and if I don't get an IP within 1-minute try the other network until I get an IP. Here is the API docs for tmr which I followed in the code below.

Is there a way to switch between two or more wifi networks programatically using Lua? I am using the Lua language, however I can move to arduino IDE, if required.

wifi.setmode(wifi.STATION) myRouter = "dlink" tmr.alarm(1, 60000, tmr.ALARM_SINGLE, function()       if myRouter=="dlink" then         print("Dlink selected")         wifi.sta.config("dlink","password1")         wifi.sta.connect()                if wifi.sta.getip() == nil then                  print("NO IP yet! ,Connecting...")              else                  tmr.stop(1)                  print("Connected, IP is "..wifi.sta.getip())              end                  elseif myRouter=="cisco" then         print("Cisco selected")         wifi.sta.config("cisco","passoword2")         wifi.sta.connect()                if wifi.sta.getip() == nil then                  print("NO IP yet! ,Connecting...")              else                  tmr.stop(1)                  print("Connected, IP is "..wifi.sta.getip())              end       else          print("No network is giving an ip")                   end             end) 

What I am looking for is a callback which fires whenever the timer "tmr" expires. This way I can change the variable to myRouter="cisco". Notice in the code above i was unable to change the "myRouter" variable.

I considered using a software watchdog to monitor the conectivity all the time so if or when the WiFi drops on one network, it will trigger a reconnect by running the code above. I am not sure how to do this or how its usually done, since I am very new to lua. Please advise or point me to a resource which can help in this regard. Thanks guys.

回答1:

This is an untested piece of code quickly put together.

effectiveRouter = nil counter = 0 wifi.sta.config("dlink", "password1") tmr.alarm(1, 1000, tmr.ALARM_SEMI, function()   counter = counter + 1   if counter < 60 then     if wifi.sta.getip() == nil then       print("NO IP yet! Keep trying to connect to dlink")       tmr.start(1) -- restart     else       print("Connected to dlink, IP is "..wifi.sta.getip())       effectiveRouter = "dlink"       startProgram()     end   elseif counter < 120 then     wifi.sta.config("cisco", "password2")     if wifi.sta.getip() == nil then       print("NO IP yet! Keep trying to connect to cisco")       tmr.start(1) -- restart     else       print("Connected to cisco, IP is "..wifi.sta.getip())       effectiveRouter = "cisco"       startProgram()     end   else     print("Out of options, giving up.")   end end) 

It'll first try to connect to 'dlink' for 60s, then to 'cisco' for another 60s, and will eventually give up after that if neither attempts was successful. It uses a semi-automatic timer which is only restarted if there's no IP yet.

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