Question

我想将NodeMCU套接字客户端连接到node.js套接字服务器。我在NodeMCU中使用Lua编程语言。我为客户端尝试了这个代码，但它没有用。

wifi.setmode(wifi.STATION)
wifi.sta.config("SSID","Password")
wifi.sta.connect()
ip = wifi.sta.getip()
print("your IP is "..ip)

sk = net.createConnection(net.TCP, 0)

sk:on("receive", function ( sck,c )
  print (c)
end)

sk:on("connection", function ( sck,c )
  print("connected")
  sk:send("Helloooo...")
end)

sk:connect(3000,"192.168.1.4")

node.js服务器代码经过测试并运行良好。

var app = require('http').createServer();
var io = require('socket.io')(app);

io.on('connection', function(socket){
  console.log('someone is connected');
});

app.listen(3000);

Answer 1

你错了NodeMCU fundamentals。 NodeMCU是异步和事件驱动的，即大多数调用都是非阻塞的。

这意味着在您发出wifi.sta.connect()（没有阻止）后，您需要等到设备获得IP才能继续。这是缩写startup sequence from our docs：

function startup()
    -- do stuff here
end

print("Connecting to WiFi access point...")
wifi.setmode(wifi.STATION)
wifi.sta.config(SSID, PASSWORD)
-- wifi.sta.connect() not necessary because config() uses auto-connect=true by default
tmr.alarm(1, 1000, 1, function()
    if wifi.sta.getip() == nil then
        print("Waiting for IP address...")
    else
        tmr.stop(1)
        print("WiFi connection established, IP address: " .. wifi.sta.getip())
        print("You have 3 seconds to abort")
        print("Waiting...")
        tmr.alarm(0, 3000, 0, startup)
    end
end)

使用Lua的NodeMCU套接字客户端无法连接

1 个答案: