WiFi Module

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.getchannel()

Gets the current WiFi channel.

Syntax

wifi.getchannel()

Parameters

nil

Returns

current WiFi channel

Example

print(wifi.getchannel())

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.setmode()

wifi.getphymode()

Gets WiFi physical mode.

Syntax

wifi.getpymode()

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.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.

Syntax

wifi.setmode(mode)

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 to switch off WiFi

Returns

current mode after setup

Example

wifi.setmode(wifi.STATION)

See also

wifi.getmode()

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
Parameters Typical Power Usage
Tx 802.11b, CCK 11Mbps, P OUT=+17dBm 170 mA
Tx 802.11g, OFDM 54Mbps, P OUT =+15dBm 140 mA
Tx 802.11n, MCS7 65Mbps, P OUT =+13dBm 120 mA
Rx 802.11b, 1024 bytes packet length, -80dBm 50 mA
Rx 802.11g, 1024 bytes packet length, -70dBm 56 mA
Rx 802.11n, 1024 bytes packet length, -65dBm 56 mA

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.sleeptype()

Configures the WiFi modem sleep type.

Syntax

wifi.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 modem 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.

See also

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.

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.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()

Sets the WiFi station configuration.

Syntax

wifi.sta.config(ssid, password[, auto[, bssid]])

Parameters

  • ssid string which is less than 32 bytes.
  • password string which is 8-64 or 0 bytes. Empty string indicates an open WiFi access point.
  • auto value of 0 or 1 (default)
    • 0, Disable auto connect and remain disconnected from access point
    • 1, Enable auto connect and connect to 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.
    • Note: 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"

Returns

nil

Example

--Connect to access point automatically when in range
wifi.sta.config("myssid", "password")

--Connect to Unsecured access point automatically when in range
wifi.sta.config("myssid", "")

--Connect to access point, User decides when to connect/disconnect to/from AP
wifi.sta.config("myssid", "mypassword", 0)
wifi.sta.connect()
-- ... do some WiFi stuff
wifi.sta.disconnect()

--Connect to specific access point automatically when in range
wifi.sta.config("myssid", "mypassword", "12:34:56:78:90:12")

--Connect to specific access point, User decides when to connect/disconnect to/from AP
wifi.sta.config("myssid", "mypassword", 0, "12:34:56:78:90:12")
wifi.sta.connect()
-- ... do some WiFi stuff
wifi.sta.disconnect()

See also

wifi.sta.connect()

Connects to AP in station mode.

Syntax

wifi.sta.connect()

Parameters

none

Returns

nil

Example

wifi.sta.connect()

See also

wifi.sta.disconnect()

Disconnects from AP in station mode.

Syntax

wifi.sta.disconnect()

Parameters

none

Returns

nil

See also

wifi.sta.eventMonReg()

Registers callbacks for WiFi station status events.

Syntax

  • wifi.sta.eventMonReg(wifi_status, function([previous_state]))
  • wifi.sta.eventMonReg(wifi.status, "unreg")

Parameters

  • wifi_status WiFi status you would like to set callback for, one of:
    • wifi.STA_IDLE
    • wifi.STA_CONNECTING
    • wifi.STA_WRONGPWD
    • wifi.STA_APNOTFOUND
    • wifi.STA_FAIL
    • wifi.STA_GOTIP
  • function function to perform when event occurs
  • "unreg" unregister previously registered callback
  • previous_state previous wifi_state(0 - 5)

Returns

nil

Example

--register callback
wifi.sta.eventMonReg(wifi.STA_IDLE, function() print("STATION_IDLE") end)
wifi.sta.eventMonReg(wifi.STA_CONNECTING, function() print("STATION_CONNECTING") end)
wifi.sta.eventMonReg(wifi.STA_WRONGPWD, function() print("STATION_WRONG_PASSWORD") end)
wifi.sta.eventMonReg(wifi.STA_APNOTFOUND, function() print("STATION_NO_AP_FOUND") end)
wifi.sta.eventMonReg(wifi.STA_FAIL, function() print("STATION_CONNECT_FAIL") end)
wifi.sta.eventMonReg(wifi.STA_GOTIP, function() print("STATION_GOT_IP") end)

--register callback: use previous state
wifi.sta.eventMonReg(wifi.STA_CONNECTING, function(previous_State)
    if(previous_State==wifi.STA_GOTIP) then 
        print("Station lost connection with access point\n\tAttempting to reconnect...")
    else
        print("STATION_CONNECTING")
    end
end)

--unregister callback
wifi.sta.eventMonReg(wifi.STA_IDLE, "unreg")

See also

wifi.sta.eventMonStart()

Starts WiFi station event monitor.

Syntax

wifi.sta.eventMonStart([ms])

Parameters

ms interval between checks in milliseconds, defaults to 150ms if not provided

Returns

nil

Example

--start WiFi event monitor with default interval
wifi.sta.eventMonStart()

--start WiFi event monitor with 100ms interval
wifi.sta.eventMonStart(100)

See also

wifi.sta.eventMonStop()

Stops WiFi station event monitor.

Syntax

wifi.sta.eventMonStop(["unreg all"])

Parameters

"unreg all" unregister all previously registered functions

Returns

nil

Example

--stop WiFi event monitor
wifi.sta.eventMonStop()

--stop WiFi event monitor and unregister all callbacks
wifi.sta.eventMonStop("unreg all")

See also

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("%32.s",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("%32.s",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.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

none

Returns

ssid, password, bssid_set, bssid

Note: If bssid_set is equal to 0 then bssid is irrelevant

Example

--Get current Station configuration
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.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. "18-33-44-FE-55-BB"

See also

wifi.sta.getip()

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 if hostname was successfully set, false otherwise

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.status()

Gets the current status in station mode.

Syntax

wifi.sta.status()

Parameters

nil

Returns

number´╝Ü 0~5

  • 0: STATION_IDLE,
  • 1: STATION_CONNECTING,
  • 2: STATION_WRONG_PASSWORD,
  • 3: STATION_NO_AP_FOUND,
  • 4: STATION_CONNECT_FAIL,
  • 5: STATION_GOT_IP.

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. ESP_9997C3.

Syntax

wifi.ap.config(cfg)

Parameters

  • ssdi SSID chars 1-32
  • pwd password chars 8-64
  • auth authentication one of AUTH_OPEN, AUTH_WPA_PSK, AUTH_WPA2_PSK, AUTH_WPA_WPA2_PSK, default = AUTH_OPEN
  • channel channel number 1-14 default = 6
  • hidden 0 = not hidden, 1 = hidden, default 0
  • max maximal number of connections 1-4 default=4
  • beacon beacon interval time in range 100-60000, default = 100

Returns

nil

Example:

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

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.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()

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