init.lua

-- safe library load
function load_lib(fname)
    function try_load(fname)
        if file.open(fname) then
            file.close()
            local ret, err = pcall(function() dofile(fname) end)
            if ret == false then
                print(fname .. " -- load failed!")
                print(err)
            end
            return ret
        else
            return false
        end
    end

    if try_load(fname..".lc") then return true end
    if try_load(fname..".lua") then return true end
    
    print(fname .. ".lua/.lc -- not found!")
    return false
end

-- get table length
function tablelen(table)
    local n = 0
    for _ in pairs(table) do
            n = n + 1
    end
    return n
end

load_lib("gpio")

-- init all globals
if not load_lib("config") then
    load_lib("default_config")
end

load_lib("led")

local ssid, pass = nil
local wifiReady = 0
local firstPass = 0

-- connect to WIFI network(s) from SSID list
function connectWiFi(ssid_list)
    for k,v in pairs(WIFI_AUTH) do
        if ssid_list[k] then
                ssid, pass = k, v
                break
        end
    end
    if ssid ~= nil then
        print("Connecting to "..ssid)
        -- New wifi module API used since nodemcu fw pull request #1497
        station_cfg={}
        station_cfg.ssid = ssid
        station_cfg.pwd = pass
        wifi.sta.config(station_cfg)
        tmr.alarm(WIFI_ALARM_ID, 2000, tmr.ALARM_AUTO, wifi_watch)
    else
        print("No SSIDs found")
        LedFlicker(50, 100, 5)
    end
end

-- configure WIFI network
function configureWiFi()
    LedFlicker(50, 500, 10)
    wifi.setmode(wifi.STATION)
    if tablelen(WIFI_AUTH) > 1 then
        -- scan available networks
        wifi.sta.getap(connectWiFi)
    else
        -- connect to the predefined SSID
        connectWiFi(WIFI_AUTH)
    end
end

-- WIFI connection status checking
function wifi_watch()
    status = wifi.sta.status()
    -- only do something if the status actually changed
    if status == wifi.STA_GOTIP and wifiReady == 0 then
        wifiReady = 1
        print("WiFi: connected with " .. wifi.sta.getip())
        LedBlink(400)
        --run modules on first start only
        if firstPass == 0 then
            if TELNET_MODULE == 1 then
                load_lib("telnet")
            end
            if HTTP_MODULE == 1 then
                load_lib("http")
            end
            load_lib("start")
            firstPass = 1
        end
    elseif status == wifi.STA_GOTIP and wifiReady == 1 then
        --pass
    else
        wifiReady = 0
        LedFlicker(50, 500, 10)
        print("WiFi: (re-)connecting")
    end
end

-- Configure
configureWiFi()