add init.lua based on example from nodemcu docs

2 files changed, 73 insertions, 0 deletions

diff --git a/credentials.lua.example b/credentials.lua.example
new file mode 100644
index 0000000..ea73118
--- /dev/null
+++ b/credentials.lua.example
@@ -0,0 +1,2 @@
+SSID = "some-network"
+PASSWORD = "a-password"
diff --git a/init.lua b/init.lua
new file mode 100644
index 0000000..723a563
--- /dev/null
+++ b/init.lua
@@ -0,0 +1,71 @@
+-- load credentials, 'SSID' and 'PASSWORD' declared and initialize in there
+dofile("credentials.lua")
+
+function startup()
+    if file.open("init.lua") == nil then
+        print("init.lua deleted or renamed")
+    else
+        print("Running")
+        file.close("init.lua")
+        -- the actual application is stored in 'application.lua'
+        dofile("application.lua")
+    end
+end
+
+-- Define WiFi station event callbacks
+wifi_connect_event = function(T)
+  print("Connection to AP("..T.SSID..") established!")
+  print("Waiting for IP address...")
+  if disconnect_ct ~= nil then disconnect_ct = nil end
+end
+
+wifi_got_ip_event = function(T)
+  -- Note: Having an IP address does not mean there is internet access!
+  -- Internet connectivity can be determined with net.dns.resolve().
+  print("Wifi connection is ready! IP address is: "..T.IP)
+  print("Startup will resume momentarily, you have 3 seconds to abort.")
+  print("Waiting...")
+  tmr.create():alarm(3000, tmr.ALARM_SINGLE, startup)
+end
+
+wifi_disconnect_event = function(T)
+  if T.reason == wifi.eventmon.reason.ASSOC_LEAVE then
+    --the station has disassociated from a previously connected AP
+    return
+  end
+  -- total_tries: how many times the station will attempt to connect to the AP. Should consider AP reboot duration.
+  local total_tries = 75
+  print("\nWiFi connection to AP("..T.SSID..") has failed!")
+
+  --There are many possible disconnect reasons, the following iterates through
+  --the list and returns the string corresponding to the disconnect reason.
+  for key,val in pairs(wifi.eventmon.reason) do
+    if val == T.reason then
+      print("Disconnect reason: "..val.."("..key..")")
+      break
+    end
+  end
+
+  if disconnect_ct == nil then
+    disconnect_ct = 1
+  else
+    disconnect_ct = disconnect_ct + 1
+  end
+  if disconnect_ct < total_tries then
+    print("Retrying connection...(attempt "..(disconnect_ct+1).." of "..total_tries..")")
+  else
+    wifi.sta.disconnect()
+    print("Aborting connection to AP!")
+    disconnect_ct = nil
+  end
+end
+
+-- Register WiFi Station event callbacks
+wifi.eventmon.register(wifi.eventmon.STA_CONNECTED, wifi_connect_event)
+wifi.eventmon.register(wifi.eventmon.STA_GOT_IP, wifi_got_ip_event)
+wifi.eventmon.register(wifi.eventmon.STA_DISCONNECTED, wifi_disconnect_event)
+
+print("Connecting to WiFi access point...")
+wifi.setmode(wifi.STATION)
+wifi.sta.config({ssid=SSID, pwd=PASSWORD, save=true})
+-- wifi.sta.connect() not necessary because config() uses auto-connect=true by default