WiFi Module

!!! important The WiFi subsystem is maintained by background tasks that must run periodically. Any function or task that takes longer than 15ms (milliseconds) may cause the WiFi subsystem to crash. To avoid these potential crashes, it is advised that the WiFi subsystem be suspended with wifi.suspend() prior to the execution of any tasks or functions that exceed this 15ms guideline.

WiFi modes

Courtesy: content for this chapter is borrowed/inspired by the Arduino ESP8266 WiFi documentation.

Devices that connect to WiFi network are called stations (STA). Connection to Wi-Fi is provided by an access point (AP), that acts as a hub for one or more stations. The access point on the other end is connected to a wired network. An access point is usually integrated with a router to provide access from Wi-Fi network to the internet. Each access point is recognized by a SSID (Service Set IDentifier), that essentially is the name of network you select when connecting a device (station) to the WiFi.

Each ESP8266 module can operate as a station, so we can connect it to the WiFi network. It can also operate as a soft access point (soft-AP), to establish its own WiFi network. Therefore, we can connect other stations to such modules. Third, ESP8266 is also able to operate both in station and soft access point mode at the same time. This offers the possibility of building e.g. mesh networks.

Station

Station (STA) mode is used to get the ESP8266 connected to a WiFi network established by an access point.

Soft Access Point

An access point (AP) is a device that provides access to Wi-Fi network to other devices (stations) and connects them further to a wired network. ESP8266 can provide similar functionality except it does not have interface to a wired network. Such mode of operation is called soft access point (soft-AP). The maximum number of stations connected to the soft-AP is five.

The soft-AP mode is often used and an intermediate step before connecting ESP to a WiFi in a station mode. This is when SSID and password to such network is not known upfront. The module first boots in soft-AP mode, so we can connect to it using a laptop or a mobile phone. Then we are able to provide credentials to the target network. Once done ESP is switched to the station mode and can connect to the target WiFi.

Such functionality is provided by the NodeMCU enduser setup module.

Station + Soft Access Point

Another handy application of soft-AP mode is to set up mesh networks. ESP can operate in both soft-AP and Station mode so it can act as a node of a mesh network.

Function reference

The NodeMCU WiFi control is spread across several tables:

• wifi for overall WiFi configuration
• wifi.sta for station mode functions
• wifi.ap for wireless access point (WAP or simply AP) functions
• wifi.ap.dhcp for DHCP server control
• wifi.eventmon for wifi event monitor
• wifi.monitor for wifi monitor mode

wifi.getchannel()

Gets the current WiFi channel.

Syntax

wifi.getchannel()

Parameters

nil

Returns

current WiFi channel

wifi.getcountry()

Get the current country info.

Syntax

wifi.getcountry()

Parameters

nil

Returns

• country_info this table contains the current country info configuration
  • country Country code, 2 character string.
  • start_ch Starting channel.
  • end_ch Ending channel.
  • policy The policy parameter determines which country info configuration to use, country info given to station by AP or local configuration.
    • 0 Country policy is auto, NodeMCU will use the country info provided by AP that the station is connected to.
    • 1 Country policy is manual, NodeMCU will use locally configured country info.

Example

for k, v in pairs(wifi.getcountry()) do
  print(k, v)
end

See also

wifi.setcountry()

wifi.getdefaultmode()

Gets default WiFi operation mode.

Syntax

wifi.getdefaultmode()

Parameters

nil

Returns

The WiFi mode, as one of the wifi.STATION, wifi.SOFTAP, wifi.STATIONAP or wifi.NULLMODE constants.

See also

wifi.getmode() wifi.setmode()

wifi.getmode()

Gets WiFi operation mode.

Syntax

wifi.getmode()

Parameters

nil

Returns

The WiFi mode, as one of the wifi.STATION, wifi.SOFTAP, wifi.STATIONAP or wifi.NULLMODE constants.

See also

wifi.getdefaultmode() wifi.setmode()

wifi.getphymode()

Gets WiFi physical mode.

Syntax

wifi.getphymode()

Parameters

none

Returns

The current physical mode as one of wifi.PHYMODE_B, wifi.PHYMODE_G or wifi.PHYMODE_N.

See also

wifi.setphymode()

wifi.nullmodesleep()

Configures whether or not WiFi automatically goes to sleep in NULL_MODE. Enabled by default.

!!! note This function does not store it's setting in flash, if auto sleep in NULL_MODE is not desired, wifi.nullmodesleep(false) must be called after power-up, restart, or wake from deep sleep.

Syntax

wifi.nullmodesleep([enable])

Parameters

• enable
  • true Enable WiFi auto sleep in NULL_MODE. (Default setting)
  • false Disable WiFi auto sleep in NULL_MODE.

Returns

• sleep_enabled Current/New NULL_MODE sleep setting
  • If wifi.nullmodesleep() is called with no arguments, current setting is returned.
  • If wifi.nullmodesleep() is called with enable argument, confirmation of new setting is returned.

wifi.resume()

Wake up WiFi from suspended state or cancel pending wifi suspension.

!!! attention This is disabled by default. Modify PMSLEEP_ENABLE in app/include/user_config.h to enable it.

!!! note Wifi resume occurs asynchronously, this means that the resume request will only be processed when control of the processor is passed back to the SDK (after MyResumeFunction() has completed). The resume callback also executes asynchronously and will only execute after wifi has resumed normal operation.

Syntax

wifi.resume([resume_cb])

Parameters

• resume_cb Callback to execute when WiFi wakes from suspension. !!! note "Note:"

  Any previously provided callbacks will be replaced!

Returns

nil

Example

--Resume wifi from timed or indefinite sleep
wifi.resume()

--Resume wifi from timed or indefinite sleep w/ resume callback
wifi.resume(function() print("WiFi resume") end)

See also

• wifi.suspend()
• node.sleep()
• node.dsleep()

wifi.setcountry()

Set the current country info.

Syntax

wifi.setcountry(country_info)

Parameters

• country_info This table contains the country info configuration. (If a blank table is passed to this function, default values will be configured.)
  • country Country code, 2 character string containing the country code (a list of country codes can be found here). (Default:"CN")
  • start_ch Starting channel (range:1-14). (Default:1)
  • end_ch Ending channel, must not be less than starting channel (range:1-14). (Default:13)
  • policy The policy parameter determines which country info configuration to use, country info given to station by AP or local configuration. (default:wifi.COUNTRY_AUTO)
    • wifi.COUNTRY_AUTO Country policy is auto, NodeMCU will use the country info provided by AP that the station is connected to.
      • while in stationAP mode, beacon/probe respose will reflect the country info of the AP that the station is connected to.
    • wifi.COUNTRY_MANUAL Country policy is manual, NodeMCU will use locally configured country info.

Returns

true If configuration was sucessful.

Example

do
  country_info={}
  country_info.country="US"
  country_info.start_ch=1
  country_info.end_ch=13
  country_info.policy=wifi.COUNTRY_AUTO;
  wifi.setcountry(country_info)
end

--compact version
  wifi.setcountry({country="US", start_ch=1, end_ch=13, policy=wifi.COUNTRY_AUTO})

--Set defaults
  wifi.setcountry({})

See also

wifi.getcountry()

wifi.setmode()

Configures the WiFi mode to use. NodeMCU can run in one of four WiFi modes:

• Station mode, where the NodeMCU device joins an existing network
• Access point (AP) mode, where it creates its own network that others can join
• Station + AP mode, where it both creates its own network while at the same time being joined to another existing network
• WiFi off

When using the combined Station + AP mode, the same channel will be used for both networks as the radio can only listen on a single channel.

!!! note WiFi configuration will be retained until changed even if device is turned off.

Syntax

wifi.setmode(mode[, save])

Parameters

• mode value should be one of
  • wifi.STATION for when the device is connected to a WiFi router. This is often done to give the device access to the Internet.
  • wifi.SOFTAP for when the device is acting only as an access point. This will allow you to see the device in the list of WiFi networks (unless you hide the SSID, of course). In this mode your computer can connect to the device, creating a local area network. Unless you change the value, the NodeMCU device will be given a local IP address of 192.168.4.1 and assign your computer the next available IP address, such as 192.168.4.2.
  • wifi.STATIONAP is the combination of wifi.STATION and wifi.SOFTAP. It allows you to create a local WiFi connection and connect to another WiFi router.
  • wifi.NULLMODE changing WiFi mode to NULL_MODE will put wifi into a low power state similar to MODEM_SLEEP, provided wifi.nullmodesleep(false) has not been called.
• save choose whether or not to save wifi mode to flash
  • true WiFi mode configuration will be retained through power cycle. (Default)
  • false WiFi mode configuration will not be retained through power cycle.

Returns

current mode after setup

Example

wifi.setmode(wifi.STATION)

See also

wifi.getmode() wifi.getdefaultmode()

wifi.setphymode()

Sets WiFi physical mode.

• wifi.PHYMODE_B 802.11b, more range, low Transfer rate, more current draw
• wifi.PHYMODE_G 802.11g, medium range, medium transfer rate, medium current draw
• wifi.PHYMODE_N 802.11n, least range, fast transfer rate, least current draw (STATION ONLY) Information from the Espressif datasheet v4.3

Syntax

wifi.setphymode(mode)

Parameters

mode one of the following

• wifi.PHYMODE_B
• wifi.PHYMODE_G
• wifi.PHYMODE_N

Returns

physical mode after setup

See also

wifi.getphymode()

wifi.setmaxtxpower()

Sets WiFi maximum TX power. This setting is not persisted across power cycles, and the Espressif SDK documentation does not specify if the setting persists after deep sleep. The default value used is read from byte 34 of the ESP8266 init data, and its value is hence defined by the manufacturer.

The default value, 82, corresponds to maximum TX power. Lowering this setting could reduce power consumption on battery backed devices.

Syntax

wifi.setmaxtxpower(max_tpw)

Parameters

max_tpw maximum value of RF Tx Power, unit: 0.25 dBm, range [0, 82].

Returns

nil

See also

flash SDK init data

wifi.startsmart()

Starts to auto configuration, if success set up SSID and password automatically.

Intended for use with SmartConfig apps, such as Espressif's Android & iOS app.

Only usable in wifi.STATION mode.

!!! important

SmartConfig is disabled by default and can be enabled by setting `WIFI_SMART_ENABLE` in [`user_config.h`](https://github.com/nodemcu/nodemcu-firmware/blob/dev/app/include/user_config.h#L96) before you build the firmware.

Syntax

wifi.startsmart(type, callback)

Parameters

• type 0 for ESP_TOUCH, or 1 for AIR_KISS.
• callback a callback function of the form function(ssid, password) end which gets called after configuration.

Returns

nil

Example

wifi.setmode(wifi.STATION)
wifi.startsmart(0,
	function(ssid, password)
		print(string.format("Success. SSID:%s ; PASSWORD:%s", ssid, password))
	end
)

See also

wifi.stopsmart()

wifi.stopsmart()

Stops the smart configuring process.

Syntax

wifi.stopsmart()

Parameters

none

Returns

nil

See also

wifi.startsmart()

wifi.suspend()

Suspend Wifi to reduce current consumption.

!!! attention This is disabled by default. Modify PMSLEEP_ENABLE in app/include/user_config.h to enable it.

!!! note Wifi suspension occurs asynchronously, this means that the suspend request will only be processed when control of the processor is passed back to the SDK (after MySuspendFunction() has completed). The suspend callback also executes asynchronously and will only execute after wifi has been successfully been suspended.

Syntax

wifi.suspend({duration[, suspend_cb, resume_cb, preserve_mode]})

Parameters

• duration Suspend duration in microseconds(μs). If a suspend duration of 0 is specified, suspension will be indefinite (Range: 0 or 50000 - 268435454 μs (0:4:28.000454))
• suspend_cb Callback to execute when WiFi is suspended. (Optional)
• resume_cb Callback to execute when WiFi wakes from suspension. (Optional)
• preserve_mode preserve current WiFi mode through node sleep. (Optional, Default: true)
• If true, Station and StationAP modes will automatically reconnect to previously configured Access Point when NodeMCU resumes.
• If false, discard WiFi mode and leave NodeMCU in wifi.NULL_MODE. WiFi mode will be restored to original mode on restart.

Returns

• suspend_state if no parameters are provided, current WiFi suspension state will be returned
• States:
• 0 WiFi is awake.
• 1 WiFi suspension is pending. (Waiting for idle task)
• 2 WiFi is suspended.

Example

--get current wifi suspension state
print(wifi.suspend())

--Suspend WiFi for 10 seconds with suspend/resume callbacks
 cfg={}
 cfg.duration=10*1000*1000
 cfg.resume_cb=function() print("WiFi resume") end
 cfg.suspend_cb=function() print("WiFi suspended") end

 wifi.suspend(cfg)

--Suspend WiFi for 10 seconds with suspend/resume callbacks and discard WiFi mode
 cfg={}
 cfg.duration=10*1000*1000
 cfg.resume_cb=function() print("WiFi resume") end
 cfg.suspend_cb=function() print("WiFfi suspended") end
 cfg.preserve_mode=false

 wifi.suspend(cfg)

See also

• wifi.resume()
• node.sleep()
• node.dsleep()

wifi.sta Module

wifi.sta.autoconnect()

Auto connects to AP in station mode.

Syntax

wifi.sta.autoconnect(auto)

Parameters

auto 0 to disable auto connecting, 1 to enable auto connecting

Returns

nil

Example

wifi.sta.autoconnect(1)

See also

• wifi.sta.config()
• wifi.sta.connect()
• wifi.sta.disconnect()

wifi.sta.changeap()

Select Access Point from list returned by wifi.sta.getapinfo()

Syntax

wifi.sta.changeap(ap_index)

Parameters

ap_index Index of Access Point you would like to change to. (Range:1-5)

• Corresponds to index used by wifi.sta.getapinfo() and wifi.sta.getapindex()

Returns

• true Success
• false Failure

Example

wifi.sta.changeap(4)

See also

• wifi.sta.getapinfo()
• wifi.sta.getapindex()

wifi.sta.clearconfig()

Clears the currently saved WiFi station configuration, erasing it from the flash. May be useful for certain factory-reset scenarios when a full node.restore() is not desired, or to prepare for using End-User Setup so that the SoftAP is able to lock onto a single hardware radio channel.

Syntax

wifi.sta.clearconfig()

Parameters

none

Returns

• true Success
• false Failure

See also

• wifi.sta.config()
• node.restore()

wifi.sta.config()

Sets the WiFi station configuration.

!!! note It is not advised to assume that the WiFi is connected at any time during initialization start-up. WiFi connection status should be validated either by using a WiFi event callback or by polling the status on a timer.

Syntax

wifi.sta.config(station_config)

Parameters

• station_config table containing configuration data for station
  • ssid string which is less than 32 bytes.
  • pwd string which is 0-64. Empty string indicates an open WiFi access point. Note: WPA requires a minimum of 8-characters, but the ESP8266 can also connect to a WEP access point (a 40-bit WEP key can be provided as its corresponding 5-character ASCII string).
  • auto defaults to true
    • true to enable auto connect and connect to access point, hence with auto=true there's no need to call wifi.sta.connect()
    • false to disable auto connect and remain disconnected from access point
  • bssid string that contains the MAC address of the access point (optional)
    • You can set BSSID if you have multiple access points with the same SSID.
    • If you set BSSID for a specific SSID and would like to configure station to connect to the same SSID only without the BSSID requirement, you MUST first configure to station to a different SSID first, then connect to the desired SSID
    • The following formats are valid:
      • "DE:C1:A5:51:F1:ED"
      • "AC-1D-1C-B1-0B-22"
      • "DE AD BE EF 7A C0"
  • save Save station configuration to flash.
    • true configuration will be retained through power cycle. (Default).
    • false configuration will not be retained through power cycle.
  • Event callbacks will only be available if WIFI_SDK_EVENT_MONITOR_ENABLE is uncommented in user_config.h
    • Please note: To ensure all station events are handled at boot time, all relevant callbacks must be registered as early as possible in init.lua with either wifi.sta.config() or wifi.eventmon.register().
    • connected_cb: Callback to execute when station is connected to an access point. (Optional)
      • Items returned in table :
        • SSID: SSID of access point. (format: string)
        • BSSID: BSSID of access point. (format: string)
        • channel: The channel the access point is on. (format: number)
    • disconnected_cb: Callback to execute when station is disconnected from an access point. (Optional)
      • Items returned in table :
        • SSID: SSID of access point. (format: string)
        • BSSID: BSSID of access point. (format: string)
        • reason: See wifi.eventmon.reason below. (format: number)
    • authmode_change_cb: Callback to execute when the access point has changed authorization mode. (Optional)
      • Items returned in table :
      • old_auth_mode: Old wifi authorization mode. (format: number)
      • new_auth_mode: New wifi authorization mode. (format: number)
    • got_ip_cb: Callback to execute when the station received an IP address from the access point. (Optional)
      • Items returned in table :
        • IP: The IP address assigned to the station. (format: string)
        • netmask: Subnet mask. (format: string)
        • gateway: The IP address of the access point the station is connected to. (format: string)
    • dhcp_timeout_cb: Station DHCP request has timed out. (Optional)
      • Blank table is returned.

Returns

• true Success
• false Failure

Example

--connect to Access Point (DO NOT save config to flash)
station_cfg={}
station_cfg.ssid="NODE-AABBCC"
station_cfg.pwd="password"
station_cfg.save=false
wifi.sta.config(station_cfg)

--connect to Access Point (DO save config to flash)
station_cfg={}
station_cfg.ssid="NODE-AABBCC"
station_cfg.pwd="password"
station_cfg.save=true
wifi.sta.config(station_cfg)

--connect to Access Point with specific MAC address (DO save config to flash)
station_cfg={}
station_cfg.ssid="NODE-AABBCC"
station_cfg.pwd="password"
station_cfg.bssid="AA:BB:CC:DD:EE:FF"
wifi.sta.config(station_cfg)

--configure station but don't connect to Access point (DO save config to flash)
station_cfg={}
station_cfg.ssid="NODE-AABBCC"
station_cfg.pwd="password"
station_cfg.auto=false
wifi.sta.config(station_cfg)

See also

• wifi.sta.clearconfig()
• wifi.sta.connect()
• wifi.sta.disconnect()
• wifi.sta.getapinfo()

wifi.sta.connect()

Connects to the configured AP in station mode. You only ever need to call this if auto-connect was disabled in wifi.sta.config().

Syntax

wifi.sta.connect([connected_cb])

Parameters

• connected_cb: Callback to execute when station is connected to an access point. (Optional)
  • Items returned in table :
    • SSID: SSID of access point. (format: string)
    • BSSID: BSSID of access point. (format: string)
    • channel: The channel the access point is on. (format: number)

Returns

nil

See also

• wifi.sta.disconnect()
• wifi.sta.config()

wifi.sta.disconnect()

Disconnects from AP in station mode.

!!! note Please note that disconnecting from Access Point does not reduce power consumption. If power saving is your goal, please refer to the description for wifi.NULLMODE in the function wifi.setmode() for more details.

Syntax

wifi.sta.disconnect([disconnected_cb])

Parameters

• disconnected_cb: Callback to execute when station is disconnected from an access point. (Optional)
  • Items returned in table :
    • SSID: SSID of access point. (format: string)
    • BSSID: BSSID of access point. (format: string)
    • reason: See wifi.eventmon.reason below. (format: number)

Returns

nil

See also

• wifi.sta.config()
• wifi.sta.connect()

wifi.sta.getap()

Scans AP list as a Lua table into callback function.

Syntax

wifi.sta.getap([[cfg], format,] callback(table))

Parameters

• cfg table that contains scan configuration
  • ssid SSID == nil, don't filter SSID
  • bssid BSSID == nil, don't filter BSSID
  • channel channel == 0, scan all channels, otherwise scan set channel (default is 0)
  • show_hidden show_hidden == 1, get info for router with hidden SSID (default is 0)
• format select output table format, defaults to 0
  • 0: old format (SSID : Authmode, RSSI, BSSID, Channel), any duplicate SSIDs will be discarded
  • 1: new format (BSSID : SSID, RSSI, auth mode, Channel)
• callback(table) a callback function to receive the AP table when the scan is done. This function receives a table, the key is the BSSID, the value is other info in format: SSID, RSSID, auth mode, channel.

Returns

nil

Example

-- print AP list in old format (format not defined)
function listap(t)
	for k,v in pairs(t) do
		print(k.." : "..v)
	end
end
wifi.sta.getap(listap)

-- Print AP list that is easier to read
function listap(t) -- (SSID : Authmode, RSSI, BSSID, Channel)
	print("\n"..string.format("%32s","SSID").."\tBSSID\t\t\t\t  RSSI\t\tAUTHMODE\tCHANNEL")
	for ssid,v in pairs(t) do
		local authmode, rssi, bssid, channel = string.match(v, "([^,]+),([^,]+),([^,]+),([^,]+)")
		print(string.format("%32s",ssid).."\t"..bssid.."\t  "..rssi.."\t\t"..authmode.."\t\t\t"..channel)
	end
end
wifi.sta.getap(listap)

-- print AP list in new format
function listap(t)
	for k,v in pairs(t) do
		print(k.." : "..v)
	end
end
wifi.sta.getap(1, listap)

-- Print AP list that is easier to read
function listap(t) -- (SSID : Authmode, RSSI, BSSID, Channel)
 	print("\n\t\t\tSSID\t\t\t\t\tBSSID\t\t\t  RSSI\t\tAUTHMODE\t\tCHANNEL")
  	for bssid,v in pairs(t) do
   		local ssid, rssi, authmode, channel = string.match(v, "([^,]+),([^,]+),([^,]+),([^,]*)")
    	print(string.format("%32s",ssid).."\t"..bssid.."\t  "..rssi.."\t\t"..authmode.."\t\t\t"..channel)
	end
end
wifi.sta.getap(1, listap)

--check for specific AP
function listap(t)
 	print("\n\t\t\tSSID\t\t\t\t\tBSSID\t\t\t  RSSI\t\tAUTHMODE\t\tCHANNEL")
	for bssid,v in pairs(t) do
		local ssid, rssi, authmode, channel = string.match(v, "([^,]+),([^,]+),([^,]+),([^,]*)")
		print(string.format("%32s",ssid).."\t"..bssid.."\t  "..rssi.."\t\t"..authmode.."\t\t\t"..channel)
	end
end
scan_cfg = {}
scan_cfg.ssid = "myssid"
scan_cfg.bssid = "AA:AA:AA:AA:AA:AA"
scan_cfg.channel = 0
scan_cfg.show_hidden = 1
wifi.sta.getap(scan_cfg, 1, listap)

--get RSSI for currently configured AP
function listap(t)
	for bssid,v in pairs(t) do
		local ssid, rssi, authmode, channel = string.match(v, "([^,]+),([^,]+),([^,]+),([^,]*)")
		print("CURRENT RSSI IS: "..rssi)
	end
end
ssid, tmp, bssid_set, bssid=wifi.sta.getconfig()

scan_cfg = {}
scan_cfg.ssid = ssid
if bssid_set == 1 then scan_cfg.bssid = bssid else scan_cfg.bssid = nil end
scan_cfg.channel = wifi.getchannel()
scan_cfg.show_hidden = 0
ssid, tmp, bssid_set, bssid=nil, nil, nil, nil
wifi.sta.getap(scan_cfg, 1, listap)

See also

wifi.sta.getip()

wifi.sta.getapindex()

Get index of current Access Point stored in AP cache.

Syntax

wifi.sta.getapindex()

Parameters

none

Returns

current_index index of currently selected Access Point. (Range:1-5)

Example

print("the index of the currently selected AP is: "..wifi.sta.getapindex())

See also

• wifi.sta.getapindex()
• wifi.sta.getapinfo()
• wifi.sta.changeap()

wifi.sta.getapinfo()

Get information of APs cached by ESP8266 station.

!!! Note Any Access Points configured with save disabled wifi.sta.config({save=false}) will populate this list (appearing to overwrite APs stored in flash) until restart.

Syntax

wifi.sta.getapinfo()

Parameters

nil

Returns

• ap_info
  • qty quantity of APs returned
  • 1-5 index of AP. (the index corresponds to index used by wifi.sta.changeap() and wifi.sta.getapindex())
  • ssid ssid of Access Point
  • pwd password for Access Point, nil if no password was configured
  • bssid MAC address of Access Point
    • nil will be returned if no MAC address was configured during station configuration.

Example

--print stored access point info
do
  for k,v in pairs(wifi.sta.getapinfo()) do
    if (type(v)=="table") then
      print(" "..k.." : "..type(v))
      for k,v in pairs(v) do
        print("\t\t"..k.." : "..v)
      end
    else
      print(" "..k.." : "..v)
    end
  end
end

--print stored access point info(formatted)
do
  local x=wifi.sta.getapinfo()
  local y=wifi.sta.getapindex()
  print("\n Number of APs stored in flash:", x.qty)
  print(string.format("  %-6s %-32s %-64s %-18s", "index:", "SSID:", "Password:", "BSSID:"))
  for i=1, (x.qty), 1 do
    print(string.format(" %s%-6d %-32s %-64s %-18s",(i==y and ">" or " "), i, x[i].ssid, x[i].pwd and x[i].pwd or type(nil), x[i].bssid and x[i].bssid or type(nil)))
  end
end

See also

• wifi.sta.getapindex()
• wifi.sta.setaplimit()
• wifi.sta.changeap()
• wifi.sta.config()

wifi.sta.getbroadcast()

Gets the broadcast address in station mode.

Syntax

wifi.sta.getbroadcast()

Parameters

nil

Returns

broadcast address as string, for example "192.168.0.255", returns nil if IP address = "0.0.0.0".

See also

wifi.sta.getip()

wifi.sta.getconfig()

Gets the WiFi station configuration.

Syntax

wifi.sta.getconfig()

Parameters

• return_table
  • true returns data in a table
  • false returns data in the old format (default)

Returns

If return_table is true:

• config_table
  • ssid ssid of Access Point.
  • pwd password to Access Point, nil if no password was configured
  • bssid_set will return true if the station was configured specifically to connect to the AP with the matching bssid.
  • bssid If a connection has been made to the configured AP this field will contain the AP's MAC address. Otherwise "ff:ff:ff:ff:ff:ff" will be returned.

If return_table is false:

• ssid, password, bssid_set, bssid, if bssid_set is equal to 0 then bssid is irrelevant

Example

--Get current Station configuration (NEW FORMAT)
do
local sta_config=wifi.sta.getconfig(true)
print(string.format("\tCurrent station config\n\tssid:\"%s\"\tpassword:\"%s\"\n\tbssid:\"%s\"\tbssid_set:%s", sta_config.ssid, sta_config.pwd, sta_config.bssid, (sta_config.bssid_set and "true" or "false")))
end

--Get current Station configuration (OLD FORMAT)
ssid, password, bssid_set, bssid=wifi.sta.getconfig()
print("\nCurrent Station configuration:\nSSID : "..ssid
.."\nPassword  : "..password
.."\nBSSID_set  : "..bssid_set
.."\nBSSID: "..bssid.."\n")
ssid, password, bssid_set, bssid=nil, nil, nil, nil

See also

• wifi.sta.getdefaultconfig()
• wifi.sta.connect()
• wifi.sta.disconnect()

wifi.sta.getdefaultconfig()

Gets the default WiFi station configuration stored in flash.

Syntax

wifi.sta.getdefaultconfig(return_table)

Parameters

• return_table
  • true returns data in a table
  • false returns data in the old format (default)

Returns

If return_table is true:

• config_table
  • ssid ssid of Access Point.
  • pwd password to Access Point, nil if no password was configured
  • bssid_set will return true if the station was configured specifically to connect to the AP with the matching bssid.
  • bssid If a connection has been made to the configured AP this field will contain the AP's MAC address. Otherwise "ff:ff:ff:ff:ff:ff" will be returned.

If return_table is false:

• ssid, password, bssid_set, bssid, if bssid_set is equal to 0 then bssid is irrelevant

Example

--Get default Station configuration (NEW FORMAT)
do
local def_sta_config=wifi.sta.getdefaultconfig(true)
print(string.format("\tDefault station config\n\tssid:\"%s\"\tpassword:\"%s\"\n\tbssid:\"%s\"\tbssid_set:%s", def_sta_config.ssid, def_sta_config.pwd, def_sta_config.bssid, (def_sta_config.bssid_set and "true" or "false")))
end

--Get default Station configuration (OLD FORMAT)
ssid, password, bssid_set, bssid=wifi.sta.getdefaultconfig()
print("\nCurrent Station configuration:\nSSID : "..ssid
.."\nPassword  : "..password
.."\nBSSID_set  : "..bssid_set
.."\nBSSID: "..bssid.."\n")
ssid, password, bssid_set, bssid=nil, nil, nil, nil

See also

• wifi.sta.getconfig()
• wifi.sta.connect()
• wifi.sta.disconnect()

wifi.sta.gethostname()

Gets current station hostname.

Syntax

wifi.sta.gethostname()

Parameters

none

Returns

currently configured hostname

Example

print("Current hostname is: \""..wifi.sta.gethostname().."\"")

wifi.sta.getip()

Gets IP address, netmask, and gateway address in station mode.

Syntax

wifi.sta.getip()

Parameters

none

Returns

IP address, netmask, gateway address as string, for example "192.168.0.111". Returns nil if IP = "0.0.0.0".

Example

-- print current IP address, netmask, gateway
print(wifi.sta.getip())
-- 192.168.0.111  255.255.255.0  192.168.0.1
ip = wifi.sta.getip()
print(ip)
-- 192.168.0.111
ip, nm = wifi.sta.getip()
print(nm)
-- 255.255.255.0

See also

wifi.sta.getmac()

wifi.sta.getmac()

Gets MAC address in station mode.

Syntax

wifi.sta.getmac()

Parameters

none

Returns

MAC address as string e.g. "18:fe:34:a2:d7:34"

See also

wifi.sta.getip()

wifi.sta.getrssi()

Get RSSI(Received Signal Strength Indicator) of the Access Point which ESP8266 station connected to.

Syntax

wifi.sta.getrssi()

Parameters

none

Returns

• If station is connected to an access point, rssi is returned.
• If station is not connected to an access point, nil is returned.

Example

RSSI=wifi.sta.getrssi()
print("RSSI is", RSSI)

wifi.sta.setaplimit()

Set Maximum number of Access Points to store in flash.

• This value is written to flash

!!! Attention New setting will not take effect until restart.

!!! Note If 5 Access Points are stored and AP limit is set to 4, the AP at index 5 will remain until node.restore() is called or AP limit is set to 5 and AP is overwritten.

Syntax

wifi.sta.setaplimit(qty)

Parameters

qty Quantity of Access Points to store in flash. Range: 1-5 (Default: 1)

Returns

• true Success
• false Failure

Example

wifi.sta.setaplimit(5)

See also

• wifi.sta.getapinfo()

wifi.sta.sethostname()

Sets station hostname.

Syntax

wifi.sta.sethostname(hostname)

Parameters

hostname must only contain letters, numbers and hyphens('-') and be 32 characters or less with first and last character being alphanumeric

Returns

• true Success
• false Failure

Example

if (wifi.sta.sethostname("NodeMCU") == true) then
	print("hostname was successfully changed")
else
	print("hostname was not changed")
end

wifi.sta.setip()

Sets IP address, netmask, gateway address in station mode.

Syntax

wifi.sta.setip(cfg)

Parameters

cfg table contain IP address, netmask, and gateway

{
  ip = "192.168.0.111",
  netmask = "255.255.255.0",
  gateway = "192.168.0.1"
}

Returns

true if success, false otherwise

See also

wifi.sta.setmac()

wifi.sta.setmac()

Sets MAC address in station mode.

Syntax

wifi.sta.setmac(mac)

Parameters

MAC address in string e.g. "DE:AD:BE:EF:7A:C0"

Returns

true if success, false otherwise

Example

print(wifi.sta.setmac("DE:AD:BE:EF:7A:C0"))

See also

wifi.sta.setip()

wifi.sta.sleeptype()

Configures the WiFi modem sleep type to be used while station is connected to an Access Point.

!!! note Does not apply to wifi.SOFTAP, wifi.STATIONAP or wifi.NULLMODE.

Syntax

wifi.sta.sleeptype(type_wanted)

Parameters

type_wanted one of the following:

• wifi.NONE_SLEEP to keep the modem on at all times
• wifi.LIGHT_SLEEP to allow the CPU to power down under some circumstances
• wifi.MODEM_SLEEP to power down the modem as much as possible

Returns

The actual sleep mode set, as one of wifi.NONE_SLEEP, wifi.LIGHT_SLEEP or wifi.MODEM_SLEEP.

wifi.sta.status()

Gets the current status in station mode.

Syntax

wifi.sta.status()

Parameters

nil

Returns

The current state which can be one of the following:

• wifi.STA_IDLE
• wifi.STA_CONNECTING
• wifi.STA_WRONGPWD
• wifi.STA_APNOTFOUND
• wifi.STA_FAIL
• wifi.STA_GOTIP

wifi.ap Module

wifi.ap.config()

Sets SSID and password in AP mode. Be sure to make the password at least 8 characters long! If you don't it will default to no password and not set the SSID! It will still work as an access point but use a default SSID like e.g. NODE_9997C3.

Syntax

wifi.ap.config(cfg)

Parameters

• cfg table to hold configuration
  • ssid SSID chars 1-32
  • pwd password chars 8-64
  • auth authentication method, one of wifi.OPEN (default), wifi.WPA_PSK, wifi.WPA2_PSK, wifi.WPA_WPA2_PSK
  • channel channel number 1-14 default = 6
  • hidden false = not hidden, true = hidden, default = false
  • max maximum number of connections 1-4 default=4
  • beacon beacon interval time in range 100-60000, default = 100
  • save save configuration to flash.
    • true configuration will be retained through power cycle. (Default)
    • false configuration will not be retained through power cycle.
  • Event callbacks will only be available if WIFI_SDK_EVENT_MONITOR_ENABLE is uncommented in user_config.h
    • Please note: To ensure all SoftAP events are handled at boot time, all relevant callbacks must be registered as early as possible in init.lua with either wifi.ap.config() or wifi.eventmon.register().
    • staconnected_cb: Callback executed when a new client has connected to the access point. (Optional)
      • Items returned in table :
        • MAC: MAC address of client that has connected.
        • AID: SDK provides no details concerning this return value.
    • stadisconnected_cb: Callback executed when a client has disconnected from the access point. (Optional)
      • Items returned in table :
        • MAC: MAC address of client that has disconnected.
        • AID: SDK provides no details concerning this return value.
    • probereq_cb: Callback executed when a probe request was received. (Optional)
      • Items returned in table :
        • MAC: MAC address of the client that is probing the access point.
        • RSSI: Received Signal Strength Indicator of client.

Returns

• true Success
• false Failure

Example:

 cfg={}
 cfg.ssid="myssid"
 cfg.pwd="mypassword"
 wifi.ap.config(cfg)

wifi.ap.deauth()

Deauths (forcibly removes) a client from the ESP access point by sending a corresponding IEEE802.11 management packet (first) and removing the client from it's data structures (afterwards).

The IEEE802.11 reason code used is 2 for "Previous authentication no longer valid"(AUTH_EXPIRE).

Syntax

wifi.ap.deauth([MAC])

Parameters

• MAC address of station to be deauthed.
  • Note: if this field is left blank, all currently connected stations will get deauthed.

Returns

Returns true unless called while the ESP is in the STATION opmode

Example

allowed_mac_list={"18:fe:34:00:00:00", "18:fe:34:00:00:01"}

wifi.eventmon.register(wifi.eventmon.AP_STACONNECTED, function(T)
  print("\n\tAP - STATION CONNECTED".."\n\tMAC: "..T.MAC.."\n\tAID: "..T.AID)
  if(allowed_mac_list~=nil) then
    for _, v in pairs(allowed_mac_list) do
      if(v == T.MAC) then return end
    end
  end
  wifi.ap.deauth(T.MAC)
  print("\tStation DeAuthed!")
end)

See also

wifi.eventmon.register() wifi.eventmon.reason()

wifi.ap.getbroadcast()

Gets broadcast address in AP mode.

Syntax

wifi.ap.getbroadcast()

Parameters

none

Returns

broadcast address in string, for example "192.168.0.255", returns nil if IP address = "0.0.0.0".

Example

bc = wifi.ap.getbroadcast()
print(bc)
-- 192.168.0.255

See also

wifi.ap.getip()

wifi.ap.getclient()

Gets table of clients connected to device in AP mode.

Syntax

wifi.ap.getclient()

Parameters

none

Returns

table of connected clients

Example

table={}
table=wifi.ap.getclient()
for mac,ip in pairs(table) do
	print(mac,ip)
end

-- or shorter
for mac,ip in pairs(wifi.ap.getclient()) do
	print(mac,ip)
end

wifi.ap.getconfig()

Gets the current SoftAP configuration.

Syntax

wifi.ap.getconfig(return_table)

Parameters

• return_table
  • true returns data in a table
  • false returns data in the old format (default)

Returns

If return_table is true:

• config_table
  • ssid Network name
  • pwd Password, nil if no password was configured - auth Authentication Method (wifi.OPEN, wifi.WPA_PSK, wifi.WPA2_PSK or wifi.WPA_WPA2_PSK)
  • channel Channel number
  • hidden false = not hidden, true = hidden
  • max Maximum number of client connections
  • beacon Beacon interval

If return_table is false:

• ssid, password, if bssid_set is equal to 0 then bssid is irrelevant

Example

--Get SoftAP configuration table (NEW FORMAT)
do
  print("\n  Current SoftAP configuration:")
  for k,v in pairs(wifi.ap.getconfig(true)) do
      print("   "..k.." :",v)
  end
end

--Get current SoftAP configuration (OLD FORMAT)
do
  local ssid, password=wifi.ap.getconfig()
  print("\n  Current SoftAP configuration:\n   SSID : "..ssid..
    "\n   Password  :",password)
  ssid, password=nil, nil
end

wifi.ap.getdefaultconfig()

Gets the default SoftAP configuration stored in flash.

Syntax

wifi.ap.getdefaultconfig(return_table)

Parameters

• return_table
  • true returns data in a table
  • false returns data in the old format (default)

Returns

If return_table is true:

• config_table
  • ssid Network name
  • pwd Password, nil if no password was configured - auth Authentication Method (wifi.OPEN, wifi.WPA_PSK, wifi.WPA2_PSK or wifi.WPA_WPA2_PSK)
  • channel Channel number
  • hidden false = not hidden, true = hidden
  • max Maximum number of client connections
  • beacon Beacon interval

If return_table is false:

• ssid, password, if bssid_set is equal to 0 then bssid is irrelevant

Example

--Get default SoftAP configuration table (NEW FORMAT)
do
  print("\n  Default SoftAP configuration:")
  for k,v in pairs(wifi.ap.getdefaultconfig(true)) do
      print("   "..k.." :",v)
  end
end

--Get default SoftAP configuration (OLD FORMAT)
do
  local ssid, password=wifi.ap.getdefaultconfig()
  print("\n  Default SoftAP configuration:\n   SSID : "..ssid..
    "\n   Password  :",password)
  ssid, password=nil, nil
end

wifi.ap.getip()

Gets IP address, netmask and gateway in AP mode.

Syntax

wifi.ap.getip()

Parameters

none

Returns

IP address, netmask, gateway address as string, for example "192.168.0.111", returns nil if IP address = "0.0.0.0".

Example

-- print current ip, netmask, gateway
print(wifi.ap.getip())
-- 192.168.4.1  255.255.255.0  192.168.4.1
ip = wifi.ap.getip()
print(ip)
-- 192.168.4.1
ip, nm = wifi.ap.getip()
print(nm)
-- 255.255.255.0
ip, nm, gw = wifi.ap.getip()
print(gw)
-- 192.168.4.1

See also

• wifi.ap.getmac()

wifi.ap.getmac()

Gets MAC address in AP mode.

Syntax

wifi.ap.getmac()

Parameters

none

Returns

MAC address as string, for example "1A-33-44-FE-55-BB"

See also

wifi.ap.getip()

wifi.ap.setip()

Sets IP address, netmask and gateway address in AP mode.

Syntax

wifi.ap.setip(cfg)

Parameters

cfg table contain IP address, netmask, and gateway

Returns

true if successful, false otherwise

Example

cfg =
{
	ip="192.168.1.1",
	netmask="255.255.255.0",
	gateway="192.168.1.1"
}
wifi.ap.setip(cfg)

See also

wifi.ap.setmac()

wifi.ap.setmac()

Sets MAC address in AP mode.

Syntax

wifi.ap.setmac(mac)

Parameters

MAC address in byte string, for example "AC-1D-1C-B1-0B-22"

Returns

true if success, false otherwise

Example

print(wifi.ap.setmac("AC-1D-1C-B1-0B-22"))

See also

wifi.ap.setip()

wifi.ap.dhcp Module

wifi.ap.dhcp.config()

Configure the dhcp service. Currently only supports setting the start address of the dhcp address pool.

Syntax

wifi.ap.dhcp.config(dhcp_config)

Parameters

dhcp_config table containing the start-IP of the DHCP address pool, eg. "192.168.1.100"

Returns

pool_startip, pool_endip

Example

dhcp_config ={}
dhcp_config.start = "192.168.1.100"
wifi.ap.dhcp.config(dhcp_config)

wifi.ap.dhcp.start()

Starts the DHCP service.

Syntax

wifi.ap.dhcp.start()

Parameters

none

Returns

boolean indicating success

wifi.ap.dhcp.stop()

Stops the DHCP service.

Syntax

wifi.ap.dhcp.stop()

Parameters

none

Returns

boolean indicating success

wifi.eventmon Module

wifi.eventmon.register()

Register/unregister callbacks for WiFi event monitor.

• After a callback is registered, this function may be called to update a callback's function at any time

!!! note To ensure all WiFi events are caught, the Wifi event monitor callbacks should be registered as early as possible in init.lua. Any events that occur before callbacks are registered will be discarded!

Syntax

wifi.eventmon.register(Event[, function(T)])

Parameters

Event: WiFi event you would like to set a callback for.

• Valid WiFi events:
  • wifi.eventmon.STA_CONNECTED
  • wifi.eventmon.STA_DISCONNECTED
  • wifi.eventmon.STA_AUTHMODE_CHANGE
  • wifi.eventmon.STA_GOT_IP
  • wifi.eventmon.STA_DHCP_TIMEOUT
  • wifi.eventmon.AP_STACONNECTED
  • wifi.eventmon.AP_STADISCONNECTED
  • wifi.eventmon.AP_PROBEREQRECVED

Returns

Function: nil

Callback: T: Table returned by event.

• wifi.eventmon.STA_CONNECTED Station is connected to access point.
  • SSID: SSID of access point.
  • BSSID: BSSID of access point.
  • channel: The channel the access point is on.
• wifi.eventmon.STA_DISCONNECTED: Station was disconnected from access point.
  • SSID: SSID of access point.
  • BSSID: BSSID of access point.
  • reason: See wifi.eventmon.reason below.
• wifi.eventmon.STA_AUTHMODE_CHANGE: Access point has changed authorization mode.
  • old_auth_mode: Old wifi authorization mode.
  • new_auth_mode: New wifi authorization mode.
• wifi.eventmon.STA_GOT_IP: Station got an IP address.
  • IP: The IP address assigned to the station.
  • netmask: Subnet mask.
  • gateway: The IP address of the access point the station is connected to.
• wifi.eventmon.STA_DHCP_TIMEOUT: Station DHCP request has timed out.
  • Blank table is returned.
• wifi.eventmon.AP_STACONNECTED: A new client has connected to the access point.
  • MAC: MAC address of client that has connected.
  • AID: SDK provides no details concerning this return value.
• wifi.eventmon.AP_STADISCONNECTED: A client has disconnected from the access point.
  • MAC: MAC address of client that has disconnected.
  • AID: SDK provides no details concerning this return value.
• wifi.eventmon.AP_PROBEREQRECVED: A probe request was received.
  • MAC: MAC address of the client that is probing the access point.
  • RSSI: Received Signal Strength Indicator of client.
• wifi.eventmon.WIFI_MODE_CHANGE: WiFi mode has changed.
  • old_auth_mode: Old WiFi mode.
  • new_auth_mode: New WiFi mode.

Example

wifi.eventmon.register(wifi.eventmon.STA_CONNECTED, function(T)
  print("\n\tSTA - CONNECTED".."\n\tSSID: "..T.SSID.."\n\tBSSID: "..
  T.BSSID.."\n\tChannel: "..T.channel)
end)

wifi.eventmon.register(wifi.eventmon.STA_DISCONNECTED, function(T)
  print("\n\tSTA - DISCONNECTED".."\n\tSSID: "..T.SSID.."\n\tBSSID: "..
  T.BSSID.."\n\treason: "..T.reason)
end)

wifi.eventmon.register(wifi.eventmon.STA_AUTHMODE_CHANGE, function(T)
  print("\n\tSTA - AUTHMODE CHANGE".."\n\told_auth_mode: "..
  T.old_auth_mode.."\n\tnew_auth_mode: "..T.new_auth_mode)
end)

wifi.eventmon.register(wifi.eventmon.STA_GOT_IP, function(T)
  print("\n\tSTA - GOT IP".."\n\tStation IP: "..T.IP.."\n\tSubnet mask: "..
  T.netmask.."\n\tGateway IP: "..T.gateway)
end)

wifi.eventmon.register(wifi.eventmon.STA_DHCP_TIMEOUT, function()
  print("\n\tSTA - DHCP TIMEOUT")
end)

wifi.eventmon.register(wifi.eventmon.AP_STACONNECTED, function(T)
  print("\n\tAP - STATION CONNECTED".."\n\tMAC: "..T.MAC.."\n\tAID: "..T.AID)
end)

wifi.eventmon.register(wifi.eventmon.AP_STADISCONNECTED, function(T)
  print("\n\tAP - STATION DISCONNECTED".."\n\tMAC: "..T.MAC.."\n\tAID: "..T.AID)
end)

wifi.eventmon.register(wifi.eventmon.AP_PROBEREQRECVED, function(T)
  print("\n\tAP - PROBE REQUEST RECEIVED".."\n\tMAC: ".. T.MAC.."\n\tRSSI: "..T.RSSI)
end)

wifi.eventmon.register(wifi.eventmon.WIFI_MODE_CHANGED, function(T)
  print("\n\tSTA - WIFI MODE CHANGED".."\n\told_mode: "..
  T.old_mode.."\n\tnew_mode: "..T.new_mode)
end)

See also

• wifi.eventmon.unregister()

wifi.eventmon.unregister()

Unregister callbacks for WiFi event monitor.

Syntax

wifi.eventmon.unregister(Event)

Parameters

Event: WiFi event you would like to remove the callback for.

• Valid WiFi events:
  • wifi.eventmon.STA_CONNECTED
  • wifi.eventmon.STA_DISCONNECTED
  • wifi.eventmon.STA_AUTHMODE_CHANGE
  • wifi.eventmon.STA_GOT_IP
  • wifi.eventmon.STA_DHCP_TIMEOUT
  • wifi.eventmon.AP_STACONNECTED
  • wifi.eventmon.AP_STADISCONNECTED
  • wifi.eventmon.AP_PROBEREQRECVED
  • wifi.eventmon.WIFI_MODE_CHANGED

Returns

nil

Example

 wifi.eventmon.unregister(wifi.eventmon.STA_CONNECTED)

See also

• wifi.eventmon.register()

wifi.eventmon.reason

Table containing disconnect reasons.