### Start Captive Portal with Callbacks

Source: https://github.com/nodemcu/nodemcu-firmware/blob/release/docs/modules/enduser-setup.md

This example shows how to start the captive portal with optional parameters for the AP SSID, a connected callback, an error callback, and a debug callback. The `print` function is used as a simple debug callback.

```lua
enduser_setup.start(
  function()
    print("Connected to WiFi as:" .. wifi.sta.getip())
  end,
  function(err, str)
    print("enduser_setup: Err #" .. err .. ": " .. str)
  end,
  print -- Lua print function can serve as the debug callback
)
```

--------------------------------

### sobj:setup()

Source: https://github.com/nodemcu/nodemcu-firmware/blob/release/docs/lua-modules/bme280.md

Re-initializes the sensor using the same parameters as the initial setup.

```APIDOC
### sobj:setup()

Re-initializes the sensor.

### Parameters

Parameters are the same as for the [bme280.setup](#bme280setup) function.

### Return

Returned values are the same as for the [bme280.setup](#bme280setup) function.
```

--------------------------------

### Build NodeMCU Firmware with Make

Source: https://github.com/nodemcu/nodemcu-firmware/blob/release/docs/build.md

Use this command to start the build process in a native Linux environment. The default setup minimizes output verbosity.

```bash
make
```

--------------------------------

### Initial Page Load and Setup

Source: https://github.com/nodemcu/nodemcu-firmware/blob/release/app/modules/enduser_setup/enduser_setup.html

Sets up event listeners and initiates the first status and network scan upon page load. Handles URL parameters to potentially start in a specific state.

```javascript
window.onload = function() {
    let trying = $.urlParam('trying');
    ab.innerText = 'Scan for Networks';
    ab.onclick = refrAp;
    $('#aplist').onchange = function () {
        $('#ssid').value = $('#aplist').value;
        let pw = $('#wifi_password');
        if ($('#aplist').selectedOptions[0].dataset.auth > 0) {
            pw.placeholder = "Password";
            pw.disabled = false;
            pw.required = true;
        } else {
            pw.placeholder = "Open -- no password";
            pw.disabled = true;
            pw.required = false;
        }
    };
    $('#bk2').onclick = function () {
        cur('#f1')
    }
    rs = to(refr, 0.5);
    if( trying ) cur("#f3");
    refrAp();
}
```

--------------------------------

### Full Redis Example

Source: https://github.com/nodemcu/nodemcu-firmware/blob/release/docs/lua-modules/redis.md

A comprehensive example demonstrating connecting to Redis, publishing a message, and subscribing to a channel to receive and print messages.

```lua
local redis = dofile("redis.lua").connect(host, port)
redis:publish("chan1", "foo")
redis:subscribe("chan1", function(channel, msg) 
	print(channel, msg)
end)
```

--------------------------------

### Setup and Example Usage of DCC Module

Source: https://github.com/nodemcu/nodemcu-firmware/blob/release/docs/modules/dcc.md

This snippet demonstrates how to set up the DCC module with a specific pin, a command callback, and a CV callback. It also shows how to define CV values and handle different DCC commands like turnout, speed, and function commands. The `bit` module is used for bitwise operations on the accessory decoder address.

```lua
local PIN = 2 -- GPIO4

local addr = 0x12a

CV = {[29]=0, 
      [1]=bit.band(addr, 0x3f), --CV_ACCESSORY_DECODER_ADDRESS_LSB (6 bits)
      [9]=bit.band(bit.rshift(addr,6), 0x7)  --CV_ACCESSORY_DECODER_ADDRESS_MSB (3 bits)
     }

local function DCC_command(cmd, params)
    if cmd == dcc.DCC_IDLE then 
        return
    elseif cmd == dcc.DCC_TURNOUT then
        print("Turnout command") 
    elseif cmd == dcc.DCC_SPEED then
        print("Speed command") 
    elseif cmd == dcc.DCC_FUNC then
        print("Function command") 
    else
        print("Other command", cmd)
    end
    
    for i,j in pairs(params) do
        print(i, j)
    end
    print(("="):rep(80))
end

local function CV_callback(operation, param)
    local oper = ""
    local result
    if operation == dcc.CV_WRITE then
        oper = "Write"
        CV[param.CV]=param.Value
    elseif operation == dcc.CV_READ then
        oper = "Read"
        result = CV[param.CV]
    elseif operation == dcc.CV_VALID then
        oper = "Valid"
        result = 1
    elseif operation == CV_RESET then
        oper = "Reset"
        CV = {}
    end
    print(('[CV_callback] %s CV %d%s'):format(oper, param.CV or `nil`, param.Value and "\tValue: "..param.Value or "\tValue: nil"))
    return result
end

dcc.setup(PIN,
    DCC_command,
    dcc.MAN_ID_DIY, 1, 
    --bit.bor(dcc.FLAGS_AUTO_FACTORY_DEFAULT, dcc.FLAGS_DCC_ACCESSORY_DECODER, dcc.FLAGS_MY_ADDRESS_ONLY),
    bit.bor(dcc.FLAGS_AUTO_FACTORY_DEFAULT),
    0, -- ???
    CV_callback)

```

--------------------------------

### Start SmartConfig for WiFi Setup

Source: https://github.com/nodemcu/nodemcu-firmware/blob/release/docs/modules/wifi.md

Initiates the SmartConfig process to automatically set up the WiFi SSID and password. This is intended for use with companion mobile apps and requires SmartConfig to be enabled in the firmware build.

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

--------------------------------

### Install esptool.py

Source: https://github.com/nodemcu/nodemcu-firmware/blob/release/docs/getting-started.md

Install the esptool.py utility and its dependency pySerial using pip. This is the recommended tool for flashing firmware to ESPxxx chips.

```bash
$ pip install esptool
```

--------------------------------

### Start and Stop Performance Monitoring

Source: https://github.com/nodemcu/nodemcu-firmware/blob/release/docs/modules/perf.md

Starts a performance monitoring session, runs a loop, and then stops the session to retrieve and print the performance histogram. This example demonstrates basic usage for identifying CPU time spent in different code sections.

```lua
perf.start()

for j = 0, 100 do
  str = "str"..j
end

tot, out, tbl, binsize = perf.stop()

print(tot, out)
local keyset = {}
local n = 0
for k,v in pairs(tbl) do
  n=n+1
  keyset[n]=k
end
table.sort(keyset)
for kk,k in ipairs(keyset) do print(string.format("%x - %x",k, k + binsize - 1),tbl[k]) end
```

--------------------------------

### Example: Creating and Populating a SPIFFS Image

Source: https://github.com/nodemcu/nodemcu-firmware/blob/release/docs/spiffs.md

This example demonstrates how to create a SPIFFS disk image and import files into it using the spiffsimg tool interactively. It shows importing Lua scripts and HTML files, followed by listing the contents.

```bash
# spiffsimg -f flash.img -S 32m -U 524288 -i
> import myapp/lua/init.lua init.lua
> import myapp/lua/httpd.lua httpd.lua
> import myapp/html/index.html http/index.html
> import myapp/html/favicon.ico http/favicon.ico
> ls
f    122 init.lua
f   5169 httpd.lua
f   2121 http/index.html
f    880 http/favicon.ico
>^D
#

```

--------------------------------

### Configure and Start Gossip Service

Source: https://github.com/nodemcu/nodemcu-firmware/blob/release/docs/lua-modules/gossip.md

Sets up the gossip module with a seed list and debug options, then starts the service. Ensure the 'gossip' module is required before calling this configuration.

```lua
config = {
    seedList = { '192.168.0.1', '192.168.0.15' },
    debug = true,
    debugOutput = print
}
gossip = require ("gossip")
gossip.setConfig(config)
gossip.start()
```

--------------------------------

### Full WPS Example with Retries and Event Monitoring

Source: https://github.com/nodemcu/nodemcu-firmware/blob/release/docs/modules/wps.md

This comprehensive example shows how to use WPS with event monitoring for station connection and IP acquisition. It includes a retry mechanism for WPS failures and a callback function to manage the WPS process, including retries on failure, timeout, or scan errors. The example also registers event handlers for station connection and IP assignment.

```lua
do
  -- Register wifi station event callbacks
  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_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.setmode(wifi.STATION)

  wps_retry_func = function()
    if wps_retry_count == nil then wps_retry_count = 0 end
    if wps_retry_count < 3 then
      wps.disable()
      wps.enable()
      wps_retry_count = wps_retry_count + 1
      wps_retry_timer = tmr.create()
      wps_retry_timer:alarm(3000, tmr.ALARM_SINGLE, function() wps.start(wps_cb) end)
      print("retry #"..wps_retry_count)
    else
      wps_retry_count = nil
      wps_retry_timer = nil
      wps_retry_func = nil
      wps_cb = nil
    end
  end

  wps_cb = function(status)
    if status == wps.SUCCESS then
      wps.disable()
      print("WPS: success, connecting to AP...")
      wifi.sta.connect()
      wps_retry_count = nil
      wps_retry_timer = nil
      wps_retry_func = nil
      wps_cb = nil
      return
    elseif status == wps.FAILED then
      print("WPS: Failed")
      wps_retry_func()
      return
    elseif status == wps.TIMEOUT then
      print("WPS: Timeout")
      wps_retry_func()
      return
    elseif status == wps.WEP then
      print("WPS: WEP not supported")
    elseif status == wps.SCAN_ERR then
      print("WPS: AP not found")
      wps_retry_func()
      return
    else
      print(status)
    end
    wps.disable()
    wps_retry_count = nil
    wps_retry_timer = nil
    wps_retry_func = nil
    wps_cb = nil
  end
  wps.enable()
  wps.start(wps_cb)
end
```

--------------------------------

### Install esptool for Python 2.7

Source: https://github.com/nodemcu/nodemcu-firmware/wiki/Windows-Docker-LFS-esptool-ESPlorer-Workflow-Cheat-Sheet

Installs the esptool utility for Python 2.7. Navigate to the scripts directory before running.

```bash
-  cd C:\python27\scripts
-  pip install esptool
```

--------------------------------

### Enable and Start WPS

Source: https://github.com/nodemcu/nodemcu-firmware/blob/release/docs/modules/wps.md

This snippet demonstrates the basic usage of enabling WPS and starting the process. It includes a callback to handle the WPS status and attempts to connect to the AP upon success. WPS is disabled after the process completes.

```lua
wifi.setmode(wifi.STATION)
wps.enable()
wps.start(function(status)
  if status == wps.SUCCESS then
    wps.disable()
    print("WPS: Success, connecting to AP...")
    wifi.sta.connect()
    return
  elseif status == wps.FAILED then
    print("WPS: Failed")
  elseif status == wps.TIMEOUT then
    print("WPS: Timeout")
  elseif status == wps.WEP then
    print("WPS: WEP not supported")
  elseif status == wps.SCAN_ERR then
    print("WPS: AP not found")
  else
    print(status)
  end
  wps.disable()
end)
```

--------------------------------

### Create and Use CoAP Client

Source: https://github.com/nodemcu/nodemcu-firmware/blob/release/docs/modules/coap.md

Demonstrates creating a CoAP client instance and issuing GET and POST requests to a server. Note that GET request results are only printed to the console.

```lua
cc = coap.Client()
-- assume there is a coap server at ip 192.168.100
cc:get(coap.CON, "coap://192.168.18.100:5683/.well-known/core")
-- GET is not complete, the result/payload only print out in console.
cc:post(coap.NON, "coap://192.168.18.100:5683/", "Hello")
```

--------------------------------

### Enable Manual AP Configuration and Start Captive Portal

Source: https://github.com/nodemcu/nodemcu-firmware/blob/release/docs/modules/enduser-setup.md

This snippet demonstrates how to manually configure an access point using `wifi.setmode` and `wifi.ap.config`, then enables manual mode for the `enduser_setup` module. Finally, it starts the captive portal and defines callbacks for successful connection and error handling.

```lua
wifi.setmode(wifi.STATIONAP)
wifi.ap.config({ssid="MyPersonalSSID", auth=wifi.OPEN})
enduser_setup.manual(true)
enduser_setup.start(
  function()
    print("Connected to WiFi as:" .. wifi.sta.getip())
  end,
  function(err, str)
    print("enduser_setup: Err #" .. err .. ": " .. str)
  end
)
```

--------------------------------

### Start Playback with Specific Rate

Source: https://github.com/nodemcu/nodemcu-firmware/blob/release/docs/modules/pcm.md

Starts audio playback at a specified sample rate. Supported rates include pcm.RATE_1K, pcm.RATE_2K, pcm.RATE_4K, pcm.RATE_5K, pcm.RATE_8K, pcm.RATE_10K, pcm.RATE_12K, and pcm.RATE_16K.

```lua
drv:play(pcm.RATE_16K)
```

--------------------------------

### wifi.ap.dhcp.start

Source: https://github.com/nodemcu/nodemcu-firmware/blob/release/docs/modules/wifi.md

Starts the DHCP service.

```APIDOC
## wifi.ap.dhcp.start()

### Description
Starts the DHCP service.

### Parameters
none

### Returns
- `boolean` - `true` indicating success, `false` otherwise.
```

--------------------------------

### pwm.start()

Source: https://github.com/nodemcu/nodemcu-firmware/blob/release/docs/modules/pwm.md

Starts the PWM output waveform on the specified GPIO pin.

```APIDOC
## pwm.start()

### Description
PWM starts, the waveform is applied to the GPIO pin.

### Syntax
`pwm.start(pin)`

### Parameters
* `pin` (number) - Required - IO index (1-12)

### Returns
* `nil`

### See also
* [pwm.stop()](#pwmstop)
```

--------------------------------

### enduser_setup.start()

Source: https://github.com/nodemcu/nodemcu-firmware/blob/release/docs/modules/enduser-setup.md

Starts the captive portal. If the module is already running, stop() will be invoked first. Allows for optional AP SSID, and callbacks for connection success, errors, and debugging.

```APIDOC
## enduser_setup.start()

### Description
Starts the captive portal. Note: Calling start() while EUS is already running is an error, and will result in stop() to be invoked to shut down EUS.

### Syntax
`enduser_setup.start([AP_SSID,] [onConnected()], [onError(err_num, string)], [onDebug(string)])`

### Parameters
#### Parameters
- `AP_SSID` (string) - Optional - The SSID to use for the AP. Defaults to `NodeMCU_<device id>`.
- `onConnected()` (function) - Callback fired when an IP-address has been obtained, just before the enduser_setup module will terminate itself.
- `onError(err_num, string)` (function) - Callback fired if an error is encountered. `err_num` is a number describing the error, and `string` contains a description of the error.
- `onDebug(string)` (function) - Callback disabled by default (controlled by `#define ENDUSER_SETUP_DEBUG_ENABLE` in `enduser_setup.c`). Intended to be used to find internal issues in the module. `string` contains a description of what is going on.

### Returns
`nil`

### Example
```lua
enduser_setup.start(
  function()
    print("Connected to WiFi as:" .. wifi.sta.getip())
  end,
  function(err, str)
    print("enduser_setup: Err #" .. err .. ": " .. str)
  end,
  print -- Lua print function can serve as the debug callback
)
```
```

--------------------------------

### tz.getoffset()

Source: https://github.com/nodemcu/nodemcu-firmware/blob/release/lua_examples/timezone/README.md

Gets the timezone offset in seconds for a given time, along with the start and end times of that offset.

```APIDOC
## tz.getoffset()

### Description
Gets the offset (in seconds) of the time passed as the argument.

### Syntax
tz.getoffset(time)

### Parameters
#### Path Parameters
* **time** (number) - Required - The number of seconds since the epoch (same value as used by the `sntp` module).

### Returns
* **number** - The number of seconds of offset. West of Greenwich is negative.
* **number** - The start time (in epoch seconds) of this offset.
* **number** - The end time (in epoch seconds) of this offset.

### Example
```lua
tz = require('tz')
tz.setzone('eastern')
sntp.sync(nil, function(now) 
  local tm = rtctime.epoch2cal(now + tz.getoffset(now))
  print(string.format("%04d/%02d/%02d %02d:%02d:%02d", tm["year"], tm["mon"], tm["day"], tm["hour"], tm["min"], tm["sec"]))
end)
```
```

--------------------------------

### node.startup()

Source: https://github.com/nodemcu/nodemcu-firmware/blob/release/docs/modules/node.md

Get or set options that control the NodeMCU startup process. This includes options for displaying a startup banner, setting the initial CPU frequency, delaying SPIFFS filesystem mounting, and specifying an initial command to run.

```APIDOC
## node.startup()

Get/set options that control the startup process. This interface will grow over time.

#### Syntax
`node.startup([{table}])`

#### Parameters

If the argument is omitted, then no change is made to the current set of startup options. If the argument is the empty table `{}` then all options are
reset to their default values.

- `table` one or more options:
    - `banner` - set to true or false to indicate whether the startup banner should be displayed or not. (default: true)
    - `frequency` - set to node.CPU80MHZ or node.CPU160MHZ to indicate the initial CPU speed. (default: node.CPU80MHZ)
    - `delay_mount` - set to true or false to indicate whether the SPIFFS filesystem mount is delayed until it is first needed or not. (default: false)
    - `command` - set to a string which is the initial command that is run. This is the same string as in the `node.startupcommand`.

####  Returns
`table` This is the complete set of options in the state that will take effect on the next boot. Note that the `command` key may be missing -- in which
        case the default value will be used.

#### Example
```lua
node.startup({banner=false, frequency=node.CPU160MHZ})  -- Prevent printing the banner and run at 160MHz
```
```

--------------------------------

### HTML for Custom End-User Setup Page

Source: https://github.com/nodemcu/nodemcu-firmware/blob/release/docs/modules/enduser-setup.md

If `enduser_setup.html` exists on the filesystem, it will be served. This file should contain all necessary HTML, CSS, and JavaScript. It can be gzipped for smaller size, and the module will add the `Content-Encoding` header.

```html
<input name=timeout_delay type=text placeholder="Delay in seconds" />
<input name=device_name type=text placeholder="Unique device name" />
```

--------------------------------

### Get Partition Table Information

Source: https://github.com/nodemcu/nodemcu-firmware/blob/release/docs/modules/node.md

Retrieves LFS and SPIFFS partition information, including addresses and sizes. The example prints the LFS size.

```lua
print("The LFS size is " .. node.getpartitiontable().lfs_size)
```

--------------------------------

### Execute Startup Command from File

Source: https://github.com/nodemcu/nodemcu-firmware/blob/release/docs/modules/node.md

Sets a command to be executed on NodeMCU startup, specifying a compiled Lua file (.lc) to run.

```lua
node.startupcommand("@myappstart.lc")  -- Execute the compiled file myappstart.lc on startup
```

--------------------------------

### BME280 Setup with Custom Parameters

Source: https://github.com/nodemcu/nodemcu-firmware/blob/release/docs/modules/bme280.md

Configures the BME280 sensor with specific oversampling, mode, duration, and filter settings. This example uses 'game mode' settings.

```lua
bme280.setup(1, 3, 0, 3, 0, 4)
```

--------------------------------

### NodeMCU init.lua Example for WiFi Connection and Startup

Source: https://github.com/nodemcu/nodemcu-firmware/blob/release/docs/upload.md

This Lua script configures WiFi connection, handles connection events, and sets up a delayed startup sequence for the main application. It includes error handling for connection failures and a mechanism to abort startup within a short window.

```lua
-- 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})
-- wifi.sta.connect() not necessary because config() uses auto-connect=true by default

```

--------------------------------

### Sleep for 5 seconds without RF wakeup

Source: https://github.com/nodemcu/nodemcu-firmware/blob/release/docs/modules/rtctime.md

Use rtctime.dsleep with an option to prevent the RF module from starting upon wakeup. This example sleeps for 5 seconds.

```lua
-- sleep for 5 seconds, do not start RF on wakeup
rtctime.dsleep(5000000, 4)
```

--------------------------------

### l3g4200d.setup()

Source: https://github.com/nodemcu/nodemcu-firmware/blob/release/docs/modules/l3g4200d.md

Initializes the L3G4200D gyroscope module.

```APIDOC
## l3g4200d.setup()

### Description
Initializes the module.

### Syntax
l3g4200d.setup()

### Parameters
None

### Returns
`nil`
```

--------------------------------

### si7021.setup()

Source: https://github.com/nodemcu/nodemcu-firmware/blob/release/docs/modules/si7021.md

Initializes the Si7021 device on the I²C bus at the default address (0x40). This function should be called once before using other module functions.

```APIDOC
## si7021.setup()

### Description
Initializes the device on fixed I²C device address (0x40).

### Syntax
`si7021.setup()`

### Parameters
none

### Returns
`nil`

### Example
```lua
local sda, scl = 6, 5
i2c.setup(0, sda, scl, i2c.SLOW) -- call i2c.setup() only once
si7021.setup()
```
```

--------------------------------

### Get file attributes

Source: https://github.com/nodemcu/nodemcu-firmware/blob/release/docs/modules/file.md

This example retrieves and prints various attributes of a file, including its name, size, timestamp, and type (file or directory), as well as read-only and hidden status.

```lua
s = file.stat("/SD0/myfile")
print("name: " .. s.name)
print("size: " .. s.size)

t = s.time
print(string.format("%02d:%02d:%02d", t.hour, t.min, t.sec))
print(string.format("%04d-%02d-%02d", t.year, t.mon, t.day))

if s.is_dir then print("is directory") else print("is file") end
if s.is_rdonly then print("is read-only") else print("is writable") end
if s.is_hidden then print("is hidden") else print("is not hidden") end
if s.is_sys then print("is system") else print("is not system") end
if s.is_arch then print("is archive") else print("is not archive") end

s = nil
t = nil
```

--------------------------------

### ow.setup()

Source: https://github.com/nodemcu/nodemcu-firmware/blob/release/docs/modules/ow.md

Sets a specified pin to operate in one-wire mode, preparing it for communication with 1-Wire devices.

```APIDOC
## ow.setup()

### Description
Sets a pin in onewire mode.

### Syntax
`ow.setup(pin)`

### Parameters
* `pin` (number) - Required - 1~12, I/O index

### Returns
`nil`
```

--------------------------------

### i2c.setup()

Source: https://github.com/nodemcu/nodemcu-firmware/blob/release/docs/modules/i2c.md

Initializes the I2C bus with a specified bus ID, SDA and SCL pins, and the desired communication speed.

```APIDOC
## i2c.setup()

### Description
Initialize the I2C bus with the selected bus number, pins and speed.

### Syntax
i2c.setup(id, pinSDA, pinSCL, speed)

### Parameters
- `id` (number) - bus number
- `pinSDA` (number) - GPIO pin number for SDA
- `pinSCL` (number) - GPIO pin number for SCL
- `speed` (number) - communication speed (e.g., `i2c.STANDARD`, `i2c.FAST`, `i2c.FASTPLUS`)
```

--------------------------------

### Get Software Version Information

Source: https://github.com/nodemcu/nodemcu-firmware/blob/release/docs/modules/node.md

Retrieves software version details, including Git branch, commit ID, release tag, and commit timestamp. The example specifically prints the Git release tag.

```lua
print(node.info("sw_version").git_release)
```

--------------------------------

### BME680 Sensor Setup and Data Reading

Source: https://github.com/nodemcu/nodemcu-firmware/blob/release/docs/modules/bme680.md

Initializes the I2C interface and the BME680 sensor, then starts a readout process. This snippet is used for obtaining temperature, pressure, humidity, gas resistance, and QNH values from the sensor.

```lua
alt=320 -- altitude of the measurement place

sda, scl = 3, 4
i2c.setup(0, sda, scl, i2c.SLOW) -- call i2c.setup() only once

bme680.setup()

-- delay calculated by formula provided by Bosch: 121 ms, minimum working (empirical): 150 ms
bme680.startreadout(150, function () 
    T, P, H, G, QNH = bme680.read(alt)
    if T then
        local Tsgn = (T < 0 and -1 or 1); T = Tsgn*T
        print(string.format("T=%s%d.%02d", Tsgn<0 and "-" or "", T/100, T%100))
        print(string.format("QFE=%d.%03d", P/100, P%100))
        print(string.format("QNH=%d.%03d", QNH/100, QNH%100))
        print(string.format("humidity=%d.%03d%%", H/1000, H%1000))
        print(string.format("gas resistance=%d", G))
        D = bme680.dewpoint(H, T)
        local Dsgn = (D < 0 and -1 or 1); D = Dsgn*D
        print(string.format("dew_point=%s%d.%02d", Dsgn<0 and "-" or "", D/100, D%100))
    end
end)
```

--------------------------------

### Write Data to I2C Device

Source: https://github.com/nodemcu/nodemcu-firmware/blob/release/docs/modules/i2c.md

Writes data to an I2C device. This example defines a helper function to send a start condition, set the device address, write a register address, write the data, and send a stop condition. It demonstrates writing a single byte and a string.

```lua
id  = 0
sda = 1
scl = 2

-- initialize i2c, set pin 1 as sda, set pin 2 as scl
i2c.setup(id, sda, scl, i2c.FAST)

-- user defined function: write some data to device
-- with address dev_addr starting from reg_addr
function write_reg(id, dev_addr, reg_addr, data)
    i2c.start(id)
    i2c.address(id, dev_addr, i2c.TRANSMITTER)
    i2c.write(id, reg_addr)
    c = i2c.write(id, data)
    i2c.stop(id)
    return c
end
-- set register with address 0x45 of device 0x77 with value 1
count = write_reg(id, 0x77, 0x45, 1)
print(count, " bytes written")

-- write text into i2c EEPROM starting with memory address 0
count = write_reg(id, 0x50, 0, "Sample")
print(count, " bytes written")
```

--------------------------------

### dcc.setup()

Source: https://github.com/nodemcu/nodemcu-firmware/blob/release/docs/modules/dcc.md

Initializes the DCC module and links callback functions for handling DCC commands and CV operations.

```APIDOC
## dcc.setup()

### Description
Initializes the dcc module and links callback functions.

### Syntax
`dcc.setup(Pin, [AckPin, ] DCC_command, ManufacturerId, VersionId, Flags, OpsModeAddressBaseCV [, CV_table] [, CV_callback])`

### Parameters
- `Pin` (number) - The GPIO pin number connected to the DCC detector (must be interrupt capable pin).
- `AckPin` (number) - Optional. The GPIO pin number connected to the ACK mechanism. Will be set HIGH to signal an ACK.
- `DCC_command` (function) - Callback function that is called when a DCC command is decoded. `cmd` parameters is one of the following values. `params` contains a collection of parameters specific to given command.
    - `dcc.DCC_RESET`: no additional parameters, `params` is `nil`.
    - `dcc.DCC_IDLE`: no additional parameters, `params` is `nil`.
    - `dcc.DCC_SPEED`: parameters collection members are `Addr`, `AddrType`, `Speed`, `Dir`, `SpeedSteps`.
    - `dcc.DCC_SPEED_RAW`: parameters collection members are `Addr`, `AddrType`, `Raw`.
    - `dcc.DCC_FUNC`: parameters collection members are `Addr`, `AddrType`, `FuncGrp`, `FuncState`.
    - `dcc.DCC_TURNOUT`: parameters collection members are `BoardAddr`, `OutputPair`, `Direction`, `OutputPower` or `Addr`, `Direction`, `OutputPower`.
    - `dcc.DCC_ACCESSORY`: parameters collection has one member `BoardAddr` or `Addr` or `State`.
    - `dcc.DCC_RAW`: parameters collection member are `Size`, `PreambleBits`, `Data1` to `Data6`.
    - `dcc.DCC_SERVICEMODE`: parameters collection has one member `InServiceMode`.
- `ManufacturerId` (number) - Manufacturer ID returned in CV 8. Commonly `dcc.MAN_ID_DIY`.
- `VersionId` (number) - Version ID returned in CV 7.
- `Flags` (number) - One of or combination (OR operator) of:
    - `dcc.FLAGS_MY_ADDRESS_ONLY`: Only process packets with My Address.
    - `dcc.FLAGS_DCC_ACCESSORY_DECODER`: Decoder is an accessory decode.
    - `dcc.FLAGS_OUTPUT_ADDRESS_MODE`: This flag applies to accessory decoders only. Accessory decoders normally have 4 paired outputs and a single address refers to all 4 outputs. Setting this flag causes each address to refer to a single output.
    - `dcc.FLAGS_AUTO_FACTORY_DEFAULT`: Call DCC command callback with `dcc.CV_RESET` command if CV 7 & 8 == 255.
- `OpsModeAddressBaseCV` (number) - Ops Mode base address. Set it to 0?
- `CV_table` (table) - Optional. The CV values will be directly accessed from this table. metamethods will be invoked if needed. Any errors thrown will cause the CV to be considered invalid. Using this option will prevent `CV_VALID`, `CV_READ`, `CV_WRITE` and `CV_ACK_COMPLETE` from happening.
- `CV_callback` (function) - Optional. Callback function that is called when any manipulation with CV ([Configuarion Variable](https://dccwiki.com/Configuration_Variable)) is requested.
    - `dcc.CV_VALID`: To determine if a given CV is valid and (possibly) writable. This callback must determine if a CV is readable or writable and return the appropriate value (0/1/true/false). The `param` collection has members `CV` and `Writable`.
    - `dcc.CV_READ`: To read a CV. This callback must return the value of the CV. The `param` collection has one member `CV` determining the CV number to be read.
    - `dcc.CV_WRITE`: To write a value to a CV. This callback must write the Value to the CV and return the value of the CV. The `param` collection has members `CV` and `Value`. Ideally, the final value should be returned -- this may differ from the requested value.
    - `dcc.CV_RESET`: Called when CVs must be reset to their factory defaults.
    - `dcc.CV_ACK_COMPLETE`: Called when an ACK pulse has finished being sent. Only invoked if `AckPin` is specified.

### Returns
`nil`
```

--------------------------------

### Starting a Timer and Handling Errors

Source: https://github.com/nodemcu/nodemcu-firmware/blob/release/docs/modules/tmr.md

Starts a previously registered timer and checks for errors during the start operation. Essential for ensuring timers are active.

```lua
mytimer = tmr.create()
mytimer:register(5000, tmr.ALARM_SINGLE, function() print("hey there") end)
if not mytimer:start() then print("uh oh") end
```

--------------------------------

### Start Gossip Service

Source: https://github.com/nodemcu/nodemcu-firmware/blob/release/docs/lua-modules/gossip.md

Starts the gossip service, setting the 'started' flag and initiating the revision number. The revision acts as a persistent heartbeat.

```lua
gossip.start()
```

--------------------------------

### pwm.setup()

Source: https://github.com/nodemcu/nodemcu-firmware/blob/release/docs/modules/pwm.md

Configures a GPIO pin for PWM output with specified frequency and duty cycle.

```APIDOC
## pwm.setup()

### Description
Set pin to PWM mode. Only 6 pins can be set to PWM mode at the most.

### Syntax
`pwm.setup(pin, clock, duty)`

### Parameters
* `pin` (number) - Required - IO index (1-12)
* `clock` (number) - Required - PWM frequency (1-1000)
* `duty` (number) - Required - PWM duty cycle, max 1023 (10bit)

### Returns
* `nil`

### Example
```lua
-- set pin index 1 as pwm output, frequency is 100Hz, duty cycle is half.
pwm.setup(1, 100, 512)
```

### See also
* [pwm.start()](#pwmstart)
```

--------------------------------

### Pack and Unpack Example

Source: https://github.com/nodemcu/nodemcu-firmware/blob/release/docs/modules/struct.md

Demonstrates packing and unpacking a structure with a char and an array of integers using a format string.

```lua
struct.pack("<!4biiii", 10, 1, 2, 3, 4)
```

```lua
struct.unpack("<!4biiii", "\n\x01\x00\x00\x00\x02\x00\x00\x00\x03\x00\x00\x00\x04\x00\x00\x00")
```

--------------------------------

### Configure DHCP Service Start IP

Source: https://github.com/nodemcu/nodemcu-firmware/blob/release/docs/modules/wifi.md

Configures the DHCP service by setting the starting IP address for the address pool. Returns the configured start and end IP addresses.

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

--------------------------------

### softuart.setup()

Source: https://github.com/nodemcu/nodemcu-firmware/blob/release/docs/modules/softuart.md

Creates a new SoftUART instance. This function initializes a software UART port with a specified baud rate and assigns GPIO pins for transmission and reception.

```APIDOC
## softuart.setup()

### Description
Creates a new SoftUART instance. Note that rx pin cannot be shared between instances but tx pin can.

### Syntax
`softuart.setup(baudrate, txPin, rxPin)`

### Parameters
- `baudrate` (number) - SoftUART baudrate. Maximum supported is 230400.
- `txPin` (number or nil) - SoftUART tx pin. If set to `nil` `write` method will not be supported.
- `rxPin` (number or nil) - SoftUART rx pin. If set to `nil` `on("data")` method will not be supported.

### Returns
`softuart` instance.

### Example
```lua
-- Create new software UART with baudrate of 9600, D2 as Tx pin and D3 as Rx pin
s = softuart.setup(9600, 2, 3)
```
```

--------------------------------

### Start ROTable Definition

Source: https://github.com/nodemcu/nodemcu-firmware/blob/release/docs/nodemcu-lrm.md

Starts the definition of a ROTable. Requires matching LROT_END macro with the same parameters.

```C
LROT_BEGIN(rt,mt,flags)
```

--------------------------------

### Execute Startup Command as Lua Chunk

Source: https://github.com/nodemcu/nodemcu-firmware/blob/release/docs/modules/node.md

Sets a Lua chunk to be compiled and executed on NodeMCU startup, allowing for custom initialization logic.

```lua
-- Execute the LFS routine init() in preference to init.lua
node.startupcommand("=if LFS.init then LFS.init() else dofile('init.lua') end")
```

--------------------------------

### gossip.start()

Source: https://github.com/nodemcu/nodemcu-firmware/blob/release/docs/lua-modules/gossip.md

Starts the gossip service. This function initializes the `started` flag and sets the initial revision.

```APIDOC
## gossip.start()

### Description
Starts gossip, sets the `started` flag to true and initiates the `revision`. The revision (generation) main purpose is like a persistent heartbeat, as the heartbeat (measured by uptime in seconds) will obviously revert to 0.

### Method
POST

### Endpoint
/gossip/start

### Parameters
None

### Response
#### Success Response (200)
- **status** (string) - Indicates successful start.

#### Response Example
```json
{
  "status": "started"
}
```
```

--------------------------------

### Start Playback with Default Rate

Source: https://github.com/nodemcu/nodemcu-firmware/blob/release/docs/modules/pcm.md

Starts audio playback using the configured driver. If no rate is specified, it defaults to pcm.RATE_8K.

```lua
drv:play()
```

--------------------------------

### Create FTPServer Instance

Source: https://github.com/nodemcu/nodemcu-firmware/blob/release/docs/lua-modules/ftpserver.md

Initializes the FTP server with provided username and password. Debug output can be enabled with an optional flag.

```Lua
require("ftpserver"):createServer('user', 'password')
```

--------------------------------

### bme280.setup()

Source: https://github.com/nodemcu/nodemcu-firmware/blob/release/docs/modules/bme280.md

Initializes the BME280 module. This must be called before reading any sensor values.

```APIDOC
## bme280.setup()

### Description
Initializes the module. Initialization is mandatory before reading values.

### Syntax
`bme280.setup([temp_oss, press_oss, humi_oss, power_mode, inactive_duration, IIR_filter])`

### Parameters
- `temp_oss` (number, optional) - Temperature oversampling setting.
- `press_oss` (number, optional) - Pressure oversampling setting.
- `humi_oss` (number, optional) - Humidity oversampling setting.
- `power_mode` (number, optional) - Power mode setting.
- `inactive_duration` (number, optional) - Inactive duration setting.
- `IIR_filter` (number, optional) - IIR filter setting.

### Returns
`nil`
```

--------------------------------

### Install TCL Dependencies for tap-driver.expect

Source: https://github.com/nodemcu/nodemcu-firmware/blob/release/tests/README.md

On Debian systems, these are the required packages to install for using the tap-driver.expect host test runner.

```bash
apt install tcl tcllib tclx8.4 expect
```

--------------------------------

### wifi.startsmart()

Source: https://github.com/nodemcu/nodemcu-firmware/blob/release/docs/modules/wifi.md

Initiates the SmartConfig process for automatic WiFi setup (SSID and password). This is intended for use with companion mobile apps and requires the firmware to be built with WIFI_SMART_ENABLE enabled.

```APIDOC
## wifi.startsmart(type, callback)

### Description
Initiates the SmartConfig process for automatic WiFi setup (SSID and password). This is intended for use with companion mobile apps and requires the firmware to be built with WIFI_SMART_ENABLE enabled. Only usable in `wifi.STATION` mode.

### Parameters
#### Path Parameters
- `type` (number) - Required - The type of SmartConfig. 0 for ESP_TOUCH, or 1 for AIR_KISS.
- `callback` (function) - Required - A callback function of the form `function(ssid, password) end` which is called after successful configuration.

### Returns
- `nil`

### Example
```lua
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()`](#wifistopsmart)
```

--------------------------------

### Initialize MQTT Client

Source: https://github.com/nodemcu/nodemcu-firmware/blob/release/docs/modules/mqtt.md

Creates an MQTT client instance. Use this to set up the client with a unique ID and keepalive interval. Optional parameters include username, password, clean session flag, and maximum message length.

```lua
-- init mqtt client without logins, keepalive timer 120s
m = mqtt.Client("clientid", 120)

-- init mqtt client with logins, keepalive timer 120sec
m = mqtt.Client("clientid", 120, "user", "password")
```

--------------------------------

### am2320.setup()

Source: https://github.com/nodemcu/nodemcu-firmware/blob/release/docs/modules/am2320.md

Initializes the AM2320 sensor module. It may return model, version, and serial number, though these often appear as zero.

```APIDOC
## am2320.setup()

### Description
Initializes the module. Returns model, version, serial but is seams these where all zero on my model.

### Syntax
model, version, serial = am2320.setup()

### Parameters
None

### Returns
- `model`  16 bits number of model
- `version`  8 bits version number
- `serial`  32 bits serial number

   Note: I have only observed values of 0 for all of these, maybe other sensors return more sensible readings.
```

--------------------------------

### tobj:start()

Source: https://github.com/nodemcu/nodemcu-firmware/blob/release/docs/modules/tmr.md

Starts or restarts a previously configured timer. It can force a restart of an already running timer if the `restart` parameter is set to true.

```APIDOC
## tobj:start()

### Description
Starts or restarts a previously configured timer. If the timer is running, it is restarted only when the `restart` parameter is `true`. Otherwise, `false` is returned, signaling an error.

### Method
`tobj:start([restart])

### Parameters
- `restart` (boolean, optional) - Forces to restart an already running timer.

### Returns
(boolean) - `true` if the timer was (re)started, `false` on error

### Example
```lua
mytimer = tmr.create()
mytimer:register(5000, tmr.ALARM_SINGLE, function() print("hey there") end)
if not mytimer:start() then print("uh oh") end
```

### See also
- [`tobj:create()`](#tobjcreate)
- [`tobj:register()`](#tobjregister)
- [`tobj:stop()`](#tobjstop)
- [`tobj:unregister()`](#tobjunregister)
```

--------------------------------

### Start PWM Generation

Source: https://github.com/nodemcu/nodemcu-firmware/blob/release/docs/modules/pwm2.md

Starts the PWM signal generation on all configured pins. The internal LED will blink with a 0.5-second interval while PWM is active.

```lua
pwm2.start() -- starts pwm, internal led will blink with 0.5sec interval
```