### Example: Get and Print MAC Address (String version)

Source: https://arduino-esp8266.readthedocs.io/en/latest/esp8266wifi/station-class.html

Demonstrates how to retrieve the MAC address as a String and print it to the serial monitor when connected to Wi-Fi.

```cpp
if (WiFi.status() == WL_CONNECTED)
{
  Serial.printf("Connected, mac address: %s\n", WiFi.macAddress().c_str());
}
```

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

### Example: Get and Print MAC Address

Source: https://arduino-esp8266.readthedocs.io/en/latest/esp8266wifi/station-class.html

Demonstrates how to retrieve the MAC address using a pointer and print it to the serial monitor when connected to Wi-Fi.

```cpp
if (WiFi.status() == WL_CONNECTED)
{
  uint8_t macAddr[6];
  WiFi.macAddress(macAddr);
  Serial.printf("Connected, mac address: %02x:%02x:%02x:%02x:%02x:%02x\n", macAddr[0], macAddr[1], macAddr[2], macAddr[3], macAddr[4], macAddr[5]);
}
```

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

### Server Class Example

Source: https://arduino-esp8266.readthedocs.io/en/latest/esp8266wifi/server-class.html

Demonstrates the usage of WiFiServer::begin() and WiFiServer::setNoDelay() to configure and start a server. The setNoDelay(true) call disables the Nagle algorithm for potentially faster small packet transmission.

```cpp
server.begin();
server.setNoDelay(true);

```

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

### Example: Get and Print Gateway IP Address

Source: https://arduino-esp8266.readthedocs.io/en/latest/esp8266wifi/station-class.html

Demonstrates how to retrieve and print the gateway IP address. Requires a Wi-Fi connection.

```cpp
Serial.printf("Gataway IP: %s\n", WiFi.gatewayIP().toString().c_str());
```

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

### Example: Get and Print DNS IP Addresses

Source: https://arduino-esp8266.readthedocs.io/en/latest/esp8266wifi/station-class.html

Demonstrates how to retrieve and print the IP addresses of the first and second DNS servers. Requires a Wi-Fi connection.

```cpp
Serial.print("DNS #1, #2 IP: ");
WiFi.dnsIP().printTo(Serial);
Serial.print(", ");
WiFi.dnsIP(1).printTo(Serial);
Serial.println();
```

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

### Complete Synchronous WiFi Scan Example

Source: https://arduino-esp8266.readthedocs.io/en/latest/esp8266wifi/scan-examples.html

A full Arduino sketch demonstrating how to initialize WiFi in station mode, disconnect, scan for networks, and print their SSIDs. Includes necessary includes and setup.

```arduino
#include "ESP8266WiFi.h"

void setup()
{
  Serial.begin(115200);
  Serial.println();

  WiFi.mode(WIFI_STA);
  WiFi.disconnect();
  delay(100);
}

void loop()
{
  Serial.print("Scan start ... ");
  int n = WiFi.scanNetworks();
  Serial.print(n);
  Serial.println(" network(s) found");
  for (int i = 0; i < n; i++)
  {
    Serial.println(WiFi.SSID(i));
  }
  Serial.println();

  delay(5000);
}

```

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

### Start GDB on Windows (Git Version)

Source: https://arduino-esp8266.readthedocs.io/en/latest/gdb.html

Start the GDB executable for ESP8266 debugging on Windows using the Git installation path.

```batch
%userprofile%\Documents\Arduino\hardware\esp8266com\esp8266\tools\xtensa-lx106-elf\bin\xtensa-lx106-elf-gdb.exe

```

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

### Setup for Web Browser OTA Updates

Source: https://arduino-esp8266.readthedocs.io/en/latest/ota_updates/readme.html

This code initializes mDNS, sets up the HTTP update server, and starts the web server. It's required for enabling OTA updates via a web browser.

```cpp
MDNS.begin(host);

httpUpdater.setup(&httpServer);
httpServer.begin();

MDNS.addService("http", "tcp", 80);

```

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

### Example: Get and Print Local IP Address

Source: https://arduino-esp8266.readthedocs.io/en/latest/esp8266wifi/station-class.html

Demonstrates how to retrieve and print the local IP address of the ESP station's interface when connected to Wi-Fi.

```cpp
if (WiFi.status() == WL_CONNECTED)
{
  Serial.print("Connected, IP address: ");
  Serial.println(WiFi.localIP());
}
```

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

### Start WPS Configuration

Source: https://arduino-esp8266.readthedocs.io/en/latest/esp8266wifi/station-class.html

Initiates the Wi-Fi Protected Setup (WPS) process using the push-button configuration method. This function is available from SDK 1.5.4.

```cpp
#include <ESP8266WiFi.h>

void setup(void)
{
  Serial.begin(115200);
  Serial.println();

  Serial.printf("Wi-Fi mode set to WIFI_STA %s\n", WiFi.mode(WIFI_STA) ? "" : "Failed!");
  Serial.print("Begin WPS (press WPS button on your router) ... ");
  Serial.println(WiFi.beginWPSConfig() ? "Success" : "Failed");

  while (WiFi.status() != WL_CONNECTED)
  {
    delay(500);
    Serial.print(".");
  }
  Serial.println();
  Serial.print("Connected, IP address: ");
  Serial.println(WiFi.localIP());
}

void loop() {}

```

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

### Windows 7 Sketchbook Location Example

Source: https://arduino-esp8266.readthedocs.io/en/latest/faq/a04-board-generic-is-unknown.html

Provides an example path for the Arduino sketchbook location on Windows 7, guiding users to the directory containing the esp8266 hardware package.

```text
Arduino15\packages\esp8266\hardware\esp8266

```

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

### Example: Get and Print Subnet Mask

Source: https://arduino-esp8266.readthedocs.io/en/latest/esp8266wifi/station-class.html

Demonstrates how to retrieve and print the subnet mask of the station's interface. Requires a Wi-Fi connection.

```cpp
Serial.print("Subnet mask: ");
Serial.println(WiFi.subnetMask());
```

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

### Initialize GDB Stub in Setup

Source: https://arduino-esp8266.readthedocs.io/en/latest/gdb.html

Ensure the serial port is initialized and call gdbstub_init() within the void setup() function to prepare for GDB.

```c++
Serial.begin(115200);
gdbstub_init();

```

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

### WiFiServer Constructor and Begin

Source: https://arduino-esp8266.readthedocs.io/en/latest/esp8266wifi/server-class.html

Details on how to construct a WiFiServer object and start it on a specific port or the default port 23.

```APIDOC
## WiFiServer()

### Description
Constructor for the WiFiServer class.

### Method
Constructor

## begin(port)

### Description
Starts the server on the specified port.

### Method
`begin`

### Parameters
#### Path Parameters
- **port** (uint16_t) - The port number to start the server on.

## begin()

### Description
Starts the server on the default port (23) if the constructor was called without a port.

### Method
`begin`
```

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

### Start GDB on Windows (Board Manager)

Source: https://arduino-esp8266.readthedocs.io/en/latest/gdb.html

Start the GDB executable for ESP8266 debugging on Windows using the Board Manager installation path.

```batch
%userprofile%\AppData\Local\Arduino15\packages\esp8266\tools\xtensa-lx106-elf-gcc\2.5.0-3-20ed2b9\bin\xtensa-lx106-elf-gdb.exe

```

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

### Start GDB on Linux

Source: https://arduino-esp8266.readthedocs.io/en/latest/gdb.html

Navigate to the toolchain directory and start the GDB executable for ESP8266 debugging on Linux.

```bash
~/.arduino15/packages/esp8266/tools/xtensa-lx106-elf-gcc/2.5.0-4-b40a506/bin/xtensa-lx106-elf-gdb

```

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

### ESP8266 WiFi Connection and Event Handling Example

Source: https://arduino-esp8266.readthedocs.io/en/latest/esp8266wifi/generic-examples.html

This example demonstrates how to connect an ESP8266 to a Wi-Fi network and handle both IP assignment and disconnection events asynchronously. It also includes a blinking LED to show that the main loop continues to run.

```cpp
#include <ESP8266WiFi.h>

const char* ssid = "********";
const char* password = "********";

WiFiEventHandler gotIpEventHandler, disconnectedEventHandler;

bool ledState;


void setup()
{
  Serial.begin(115200);
  Serial.println();

  pinMode(LED_BUILTIN, OUTPUT);

  gotIpEventHandler = WiFi.onStationModeGotIP([](const WiFiEventStationModeGotIP& event)
  {
    Serial.print("Station connected, IP: ");
    Serial.println(WiFi.localIP());
  });

  disconnectedEventHandler = WiFi.onStationModeDisconnected([](const WiFiEventStationModeDisconnected& event)
  {
    Serial.println("Station disconnected");
  });

  Serial.printf("Connecting to %s ...\n", ssid);
  WiFi.begin(ssid, password);
}


void loop()
{
  digitalWrite(LED_BUILTIN, ledState);
  ledState = !ledState;
  delay(250);
}

```

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

### ESP8266 Boot Mode Example

Source: https://arduino-esp8266.readthedocs.io/en/latest/boards.html

This is an example of the boot messages printed by the ESP module, indicating the reset cause and boot mode.

```text
rst cause:2, boot mode:(3,6)

```

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

### Providing Hints for Compiler Cache Options

Source: https://arduino-esp8266.readthedocs.io/en/latest/faq/a06-global-build-options.html

Examples of using `mkbuildoptglobals.extra_flags` in `platform.local.txt` to provide hints about preferences or cache behavior.

```text
mkbuildoptglobals.extra_flags=--preferences_sketch            # assume file preferences.txt in the sketch folder
```

```text
mkbuildoptglobals.extra_flags=--preferences_sketch "pref.txt" # is relative to the sketch folder
```

```text
mkbuildoptglobals.extra_flags=--no_cache_core
```

```text
mkbuildoptglobals.extra_flags=--cache_core
```

```text
mkbuildoptglobals.extra_flags=--preferences_file "other-preferences.txt" # relative to IDE or full path
```

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

### Simplified Soft Access Point Setup

Source: https://arduino-esp8266.readthedocs.io/en/latest/esp8266wifi/soft-access-point-examples.html

A more concise version of the SoftAP setup using a ternary operator for printing the status. This reduces code verbosity while maintaining the same functionality.

```C++
#include <ESP8266WiFi.h>

void setup()
{
  Serial.begin(115200);
  Serial.println();

  Serial.print("Setting soft-AP ... ");
  Serial.println(WiFi.softAP("ESPsoftAP_01", "pass-to-soft-AP") ? "Ready" : "Failed!");
}

void loop()
{
  Serial.printf("Stations connected = %d\n", WiFi.softAPgetStationNum());
  delay(3000);
}


```

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

### Example Output of WiFi Scan

Source: https://arduino-esp8266.readthedocs.io/en/latest/esp8266wifi/scan-examples.html

Sample output from the complete synchronous WiFi scan example, showing the scan initiation message and a list of found network SSIDs.

```text
Scan start ... 5 network(s) found
Tech_D005107
HP-Print-A2-Photosmart 7520
ESP_0B09E3
Hack-4-fun-net
UPC Wi-Free


```

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

### Basic Soft Access Point Setup

Source: https://arduino-esp8266.readthedocs.io/en/latest/esp8266wifi/soft-access-point-examples.html

Configures the ESP8266 to act as a SoftAP with a specified SSID and password. It prints the setup status to the serial monitor and periodically reports the number of connected stations.

```C++
#include <ESP8266WiFi.h>

void setup()
{
  Serial.begin(115200);
  Serial.println();

  Serial.print("Setting soft-AP ... ");
  boolean result = WiFi.softAP("ESPsoftAP_01", "pass-to-soft-AP");
  if(result == true)
  {
    Serial.println("Ready");
  }
  else
  {
    Serial.println("Failed!");
  }
}

void loop()
{
  Serial.printf("Stations connected = %d\n", WiFi.softAPgetStationNum());
  delay(3000);
}


```

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

### Start Asynchronous Network Scan with Callback

Source: https://arduino-esp8266.readthedocs.io/en/latest/esp8266wifi/scan-class.html

Starts an asynchronous Wi-Fi network scan and specifies a callback function to be executed upon completion. Optionally includes hidden networks.

```cpp
WiFi.scanNetworksAsync(onComplete, show_hidden)
```

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

### Start UDP Listener

Source: https://arduino-esp8266.readthedocs.io/en/latest/esp8266wifi/udp-examples.html

Begin listening for incoming UDP packets on the specified local port after Wi-Fi connection is established.

```cpp
Udp.begin(localUdpPort);

```

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

### Enable WiFi at Boot Time

Source: https://arduino-esp8266.readthedocs.io/en/latest/esp8266wifi/generic-class.html

This code snippet shows how to restore the legacy behavior where WiFi starts automatically at boot. This is achieved by calling enableWiFiAtBootTime().

```cpp
#include <ESP8266WiFi.h>

void setup () {
#ifdef WIFI_IS_OFF_AT_BOOT
    enableWiFiAtBootTime(); // can be called from anywhere with the same effect
#endif
    ....
}
```

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

### Download Binary Tools (Windows)

Source: https://arduino-esp8266.readthedocs.io/en/latest/installing.html

Download the necessary binary tools for the ESP8266 core installation using a Python script. This is a required step after cloning the repository.

```bash
cd tools
python3 get.py

```

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

### Stream Extensions: Echo Service Example

Source: https://arduino-esp8266.readthedocs.io/en/latest/reference.html

Illustrates how to implement an echo service using Stream extensions for both network (TCP) and serial loopback scenarios.

```arduino
serverClient.sendAvailable(serverClient); // tcp echo service

Serial.sendAvailable(Serial);             // serial software loopback


```

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

### UDP Object and Port Setup

Source: https://arduino-esp8266.readthedocs.io/en/latest/esp8266wifi/udp-examples.html

Create a WiFiUDP object, specify a local UDP port, and define buffers for incoming and reply packets.

```cpp
WiFiUDP Udp;
unsigned int localUdpPort = 4210;
char incomingPacket[256];
char replyPacket[] = "Hi there! Got the message :-)";

```

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

### Setting a Breakpoint in GDB

Source: https://arduino-esp8266.readthedocs.io/en/latest/gdb.html

Example of setting a breakpoint using the 'break' command in GDB. This can sometimes result in multiple locations being matched.

```gdb
(gdb) break loop
Breakpoint 1 at 0x40202c84: loop. (2 locations)

```

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

### Wi-Fi Debug Output Example (Enabled)

Source: https://arduino-esp8266.readthedocs.io/en/latest/esp8266wifi/readme.html

This is a sample output when Wi-Fi debug is enabled via Serial.setDebugOutput(true), showing detailed connection steps and information.

```text
Connectingscandone
state: 0 -> 2 (b0)
state: 2 -> 3 (0)
state: 3 -> 5 (10)
add 0
aid 1
cnt

connected with sensor-net, channel 6
dhcp client start...
chg_B1:-40
...ip:192.168.1.10,mask:255.255.255.0,gw:192.168.1.9
.
Connected, IP address: 192.168.1.10


```

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

### Example Sketch with Global Defines

Source: https://arduino-esp8266.readthedocs.io/en/latest/faq/a06-global-build-options.html

This is a basic Arduino sketch that utilizes preprocessor directives to conditionally print messages based on defined macros.

```arduino
#include <umm_malloc/umm_malloc.h>  // has prototype for umm_free_heap_size_min()

void setup() {
  Serial.begin(115200);
  delay(200);
#ifdef MYTITLE1
  Serial.printf("\r\n" MYTITLE1 MYTITLE2 "\r\n");
#else
  Serial.println("ERROR:  MYTITLE1 not present");
#endif
  Serial.printf("Heap Low Watermark %u\r\n", umm_free_heap_size_min());
}

void loop() {}

```

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

### Example: Setting up Soft-AP with Custom Configuration

Source: https://arduino-esp8266.readthedocs.io/en/latest/esp8266wifi/soft-access-point-class.html

Demonstrates how to configure the soft-AP's IP address, gateway, and subnet, then set up the soft-AP itself, and finally print its IP address.

```cpp
#include <ESP8266WiFi.h>

IPAddress local_IP(192,168,4,22);
IPAddress gateway(192,168,4,9);
IPAddress subnet(255,255,255,0);

void setup()
{
  Serial.begin(115200);
  Serial.println();

  Serial.print("Setting soft-AP configuration ... ");
  Serial.println(WiFi.softAPConfig(local_IP, gateway, subnet) ? "Ready" : "Failed!");

  Serial.print("Setting soft-AP ... ");
  Serial.println(WiFi.softAP("ESPsoftAP_01") ? "Ready" : "Failed!");

  Serial.print("Soft-AP IP address = ");
  Serial.println(WiFi.softAPIP());
}

void loop() {}
```

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

### Initializing String with F Macro

Source: https://arduino-esp8266.readthedocs.io/en/latest/PROGMEM.html

Example of initializing a `String` object directly using the `F()` macro for an inline flash string.

```c++
String mystring(F("This string is stored in flash"));
```

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

### Get Filesystem Information (Standard)

Source: https://arduino-esp8266.readthedocs.io/en/latest/filesystem.html

Fills a FSInfo structure with details about the filesystem, such as total and used bytes. Returns true on success.

```C++
FSInfo fs_info;
SPIFFS.info(fs_info);
```

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

### begin

Source: https://arduino-esp8266.readthedocs.io/en/latest/filesystem.html

Mounts the file system. Must be called before any other file system APIs.

```APIDOC
## begin

### Description
Mounts the file system. This method must be called before using any other file system APIs. It returns `true` if the file system was mounted successfully, `false` otherwise. By default, `SPIFFS.begin()` will format the filesystem if it cannot mount it on the first try. Both `SPIFFS.begin()` and `LittleFS.begin()` will automatically format the filesystem if one is not detected. Be cautious, as attempting to `SPIFFS.begin()` on a LittleFS filesystem (or vice-versa) will result in data loss on that filesystem.

### Method
`begin()`

### Endpoint
N/A (Library Method)

### Parameters
None

### Request Example
```cpp
SPIFFS.begin()
or
LittleFS.begin()
```

### Response
* **bool** - `true` if the file system was mounted successfully, `false` otherwise.
```

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

### Arduino IDE Preferences Window

Source: https://arduino-esp8266.readthedocs.io/en/latest/faq/a04-board-generic-is-unknown.html

Illustrates where to find the sketchbook location in the Arduino IDE preferences, which is necessary for locating the esp8266 package installation folder.

```text
File > Preferences (Ctrl+,)

```

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

### Connect to Access Point with All Parameters

Source: https://arduino-esp8266.readthedocs.io/en/latest/esp8266wifi/station-class.html

This overload of `begin` allows specifying all connection parameters, including SSID, password, channel, BSSID, and a flag to control immediate connection. Use this for advanced control over the connection process.

```cpp
WiFi.begin(ssid, password, channel, bssid, connect)
```

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

### Get ESP8266 CPU Instruction Cycle Count

Source: https://arduino-esp8266.readthedocs.io/en/latest/libraries.html

Returns the CPU instruction cycle count since the start. Useful for precise timing of short operations.

```cpp
ESP.getCycleCount();
```

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

### WiFi.begin(ssid, password, channel, bssid, connect)

Source: https://arduino-esp8266.readthedocs.io/en/latest/esp8266wifi/station-class.html

Provides an advanced overload for establishing a station connection with optional parameters for channel, BSSID, and connection establishment control.

```APIDOC
## WiFi.begin(ssid, password, channel, bssid, connect)

### Description
Provides an advanced overload for establishing a station connection with optional parameters for channel, BSSID, and connection establishment control.

### Method
```
WiFi.begin(ssid, password, channel, bssid, connect)
```

### Parameters
#### Path Parameters
None

#### Query Parameters
None

#### Request Body
None

### Parameters
- **ssid** (string) - Required - The SSID of the Access Point (up to 32 characters).
- **password** (string) - Required - The password for the Access Point (minimum 8, maximum 64 characters).
- **channel** (integer) - Optional - The specific channel of the Access Point.
- **bssid** (string) - Optional - The MAC address of the Access Point.
- **connect** (boolean) - Optional - If set to `false`, saves parameters without establishing connection.
```

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

### Select Specific Filesystem Configuration

Source: https://arduino-esp8266.readthedocs.io/en/latest/filesystem.html

Invoke a particular filesystem configuration at sketch boot time using FLASH_MAP_SETUP_CONFIG. Choose between FLASH_MAP_OTA_FS, FLASH_MAP_MAX_FS, or FLASH_MAP_NO_FS.

```c++
FLASH_MAP_SETUP_CONFIG(FLASH_MAP_OTA_FS)
void setup () { ... }
void loop () { ... }
```

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

### Error Message for WeMos D1 Mini

Source: https://arduino-esp8266.readthedocs.io/en/latest/faq/a04-board-generic-is-unknown.html

An example of the error message when the 'WeMos D1 R2 & mini' board is not recognized by the Arduino IDE, often due to issues with the ESP8266 package installation.

```text
Board d1_mini (platform esp8266, package esp8266) is unknown
Error compiling for board WeMos D1 R2 & mini.

```

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

### Manual Signing - Using Signing Script

Source: https://arduino-esp8266.readthedocs.io/en/latest/ota_updates/readme.html

Demonstrates how to manually sign an unsigned binary using the signing.py script. This requires specifying the mode, private key, unsigned binary, and output path.

```bash
<ESP8266ArduinoPath>/tools/signing.py --mode sign --privatekey <path-to-private.key> --bin <path-to-unsigned-bin> --out <path-to-signed-binary>
```

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

### Complete ESP8266 WiFi Scan Example

Source: https://arduino-esp8266.readthedocs.io/en/latest/esp8266wifi/scan-examples.html

A full Arduino sketch for the ESP8266 that periodically triggers WiFi scans, blinks an LED, and prints scan results to the serial monitor upon completion. Includes setup for serial communication, LED, and WiFi mode.

```cpp
#include "ESP8266WiFi.h"

#define BLINK_PERIOD 250
long lastBlinkMillis;
boolean ledState;

#define SCAN_PERIOD 5000
long lastScanMillis;


void setup ()
 {
  Serial.begin(115200);
  Serial.println();

  pinMode(LED_BUILTIN, OUTPUT);

  WiFi.mode(WIFI_STA);
  WiFi.disconnect();
  delay(100);
}

void loop()
{
  long currentMillis = millis();

  // blink LED
  if (currentMillis - lastBlinkMillis > BLINK_PERIOD)
  {
    digitalWrite(LED_BUILTIN, ledState);
    ledState = !ledState;
    lastBlinkMillis = currentMillis;
  }

  // trigger Wi-Fi network scan
  if (currentMillis - lastScanMillis > SCAN_PERIOD)
  {
    WiFi.scanNetworks(true);
    Serial.print("\nScan start ... ");
    lastScanMillis = currentMillis;
  }

  // print out Wi-Fi network scan result upon completion
  int n = WiFi.scanComplete();
  if(n >= 0)
  {
    Serial.printf("%d network(s) found\n", n);
    for (int i = 0; i < n; i++)
    {
      Serial.printf("%d: %s, Ch:%d (%ddBm) %s\n", i+1, WiFi.SSID(i).c_str(), WiFi.channel(i), WiFi.RSSI(i), WiFi.encryptionType(i) == ENC_TYPE_NONE ? "open" : "");
    }
    WiFi.scanDelete();
  }
}

```

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

### HTTP Headers for Web Page

Source: https://arduino-esp8266.readthedocs.io/en/latest/esp8266wifi/server-examples.html

Example HTTP headers to inform the client about the content type, connection handling, and refresh rate. Concludes with an empty line to separate headers from the body.

```text
Content-Type: text/html
Connection: close
Refresh: 5

```

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

### WiFi.begin()

Source: https://arduino-esp8266.readthedocs.io/en/latest/esp8266wifi/station-class.html

Enables station mode and connects to the last used access point based on configuration saved in flash memory. Useful when no new connection details are needed.

```APIDOC
## WiFi.begin()

### Description
Enables station mode and connects to the last used access point based on configuration saved in flash memory. Useful when no new connection details are needed.

### Method
```
WiFi.begin()
```

### Parameters
#### Path Parameters
None

#### Query Parameters
None

#### Request Body
None

### Request Example
```
WiFi.begin()
```

### Response
#### Success Response (200)
Implicit success upon connection.

#### Response Example
None

### Notes
- It is possible that calling `begin` will result in the module being in STA + softAP mode if the module was previously placed into AP mode.
- If you notice strange behavior with DNS or other network functionality, check which mode your module is in (see `WiFi.mode()` in the Generic Class Documentation).
```

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

### Client Connection Handling

Source: https://arduino-esp8266.readthedocs.io/en/latest/esp8266wifi/server-class.html

Explains how to accept incoming client connections and the differences in the `available` method compared to the Arduino WiFi library.

```APIDOC
## accept

### Description
Returns a waiting client connection. This method is documented for the Arduino Ethernet library and is used similarly in ESP8266WiFi.

### Method
`accept`

## available

### Description
Deprecated since version 3.1.0. Use `accept` instead. In the ESP8266WiFi library, `available` functions identically to `accept`, returning a waiting client connection.

### Method
`available`
```

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

### Set up Protected Soft Access Point with Options

Source: https://arduino-esp8266.readthedocs.io/en/latest/esp8266wifi/soft-access-point-class.html

Configure a protected Wi-Fi network with SSID, pre-shared key, channel, hidden status, and maximum connections.

```cpp
WiFi.softAP(ssid, psk, channel, hidden, max_connection)
```

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

### esptool.py Upload Command Example

Source: https://arduino-esp8266.readthedocs.io/en/latest/faq/a01-upload-failed.html

This command demonstrates how to use esptool.py to write a firmware binary to an ESP8266 module. It specifies the chip, baud rate, and firmware file.

```bash
$ esptool.py --after no_reset --chip esp8266 --baud 460800 write_flash 0x0 d1-mini-firmware.bin
esptool.py v4.5.1
Found 1 serial ports
Serial port /dev/ttyUSB0
Connecting....
Chip is ESP8266EX
Features: WiFi
Crystal is 26MHz
MAC: 11:22:33:44:55:66
Uploading stub...
Running stub...
Stub running...
Changing baud rate to 460800
Changed.
Configuring flash size...
Flash will be erased from 0x00000000 to 0x0004efff...
Compressed 321440 bytes to 221714...
Wrote 321440 bytes (221714 compressed) at 0x00000000 in 5.0 seconds (effective 511.4 kbit/s)...
Hash of data verified.

Leaving...
Staying in bootloader.


```

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

### Install Python 3 SSL Certificates on macOS

Source: https://arduino-esp8266.readthedocs.io/en/latest/installing.html

Manually install SSL certificates for Python 3 on macOS if you encounter certificate verification errors during the 'get.py' script execution. This is often necessary when using Homebrew.

```bash
cd "/Applications/Python 3.7/" && sudo "./Install Certificates.command"

```

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

### Example WiFi Scan Output

Source: https://arduino-esp8266.readthedocs.io/en/latest/esp8266wifi/scan-examples.html

Sample output from the complete ESP8266 WiFi scan example, showing detected networks with their SSIDs, channels, signal strength, and security type. This output appears every 5 seconds.

```text
Scan start ... 5 network(s) found
1: Tech_D005107, Ch:6 (-72dBm)
2: HP-Print-A2-Photosmart 7520, Ch:6 (-79dBm)
3: ESP_0B09E3, Ch:9 (-89dBm) open
4: Hack-4-fun-net, Ch:9 (-91dBm)
5: UPC Wi-Free, Ch:11 (-79dBm)


```

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

### Get WiFi Channel

Source: https://arduino-esp8266.readthedocs.io/en/latest/esp8266wifi/generic-class.html

Retrieves the current WiFi channel.

```cpp
int32_t  channel (void)
```

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

### ESP.getCycleCount

Source: https://arduino-esp8266.readthedocs.io/en/latest/libraries.html

Returns the CPU instruction cycle count since start.

```APIDOC
## ESP.getCycleCount()

### Description
Returns the CPU instruction cycle count since the start of the program as an unsigned 32-bit integer. This is useful for accurate timing of very short actions.
```

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

### WiFi.begin(ssid, password)

Source: https://arduino-esp8266.readthedocs.io/en/latest/esp8266wifi/station-class.html

Establishes a connection to a specified Wi-Fi Access Point using its SSID and password. This is the primary method for initiating a station mode connection.

```APIDOC
## WiFi.begin(ssid, password)

### Description
Establishes a connection to a specified Wi-Fi Access Point using its SSID and password. This is the primary method for initiating a station mode connection.

### Method
```
WiFi.begin(ssid, password)
```

### Parameters
#### Path Parameters
None

#### Query Parameters
None

#### Request Body
None

### Request Example
```
WiFi.begin("your_ssid", "your_password")
```

### Response
#### Success Response (200)
Implicit success upon connection.

#### Response Example
None
```

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

### Get ESP8266 SDK Version

Source: https://arduino-esp8266.readthedocs.io/en/latest/libraries.html

Retrieves the SDK version as a character array.

```cpp
ESP.getSdkVersion();
```

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

### Get ESP8266 Flash Chip Speed

Source: https://arduino-esp8266.readthedocs.io/en/latest/libraries.html

Returns the flash chip frequency in Hz.

```cpp
ESP.getFlashChipSpeed(void);
```

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

### Asynchronous WiFi Scan Example

Source: https://arduino-esp8266.readthedocs.io/en/latest/esp8266wifi/scan-class.html

Demonstrates how to perform an asynchronous WiFi scan and print the results, including SSID, channel, RSSI, and encryption type. Requires WiFi.h and Serial communication.

```cpp
#include "ESP8266WiFi.h"

void prinScanResult(int networksFound)
{
  Serial.printf("%d network(s) found\n", networksFound);
  for (int i = 0; i < networksFound; i++)
  {
    Serial.printf("%d: %s, Ch:%d (%ddBm) %s\n", i + 1, WiFi.SSID(i).c_str(), WiFi.channel(i), WiFi.RSSI(i), WiFi.encryptionType(i) == ENC_TYPE_NONE ? "open" : "");
  }
}


void setup()
{
  Serial.begin(115200);
  Serial.println();

  WiFi.mode(WIFI_STA);
  WiFi.disconnect();
  delay(100);

  WiFi.scanNetworksAsync(prinScanResult);
}


void loop() {}
```

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

### Get ESP8266 Core Version

Source: https://arduino-esp8266.readthedocs.io/en/latest/libraries.html

Returns a string representing the version of the ESP8266 core.

```cpp
ESP.getCoreVersion();
```

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

### Get PHY Mode

Source: https://arduino-esp8266.readthedocs.io/en/latest/esp8266wifi/generic-class.html

Retrieves the current physical layer mode of the WiFi radio.

```APIDOC
## getPhyMode

### Description
Gets the current WiFi radio's physical layer (PHY) mode.

### Method
WiFiPhyMode_t

### Returns
The current PHY mode.
```

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

### Get WiFi Sleep Mode

Source: https://arduino-esp8266.readthedocs.io/en/latest/esp8266wifi/generic-class.html

Retrieves the current WiFi sleep mode setting.

```cpp
WiFiSleepType_t  getSleepMode ()
```

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

### Set Client Certificate for Server Authentication

Source: https://arduino-esp8266.readthedocs.io/en/latest/esp8266wifi/bearssl-client-secure-class.html

Use setClientRSACert or setClientECCert before connect() to provide a client certificate and private key when the server requests it.

```cpp
setClientRSACert(const uint8_t *certificate, size_t cert_len, const uint8_t *private_key, size_t key_len);
setClientECCert(const uint8_t *certificate, size_t cert_len, const uint8_t *private_key, size_t key_len, const uint8_t *ec_params, size_t params_len);
```

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

### Get Current WiFi Mode

Source: https://arduino-esp8266.readthedocs.io/en/latest/esp8266wifi/generic-class.html

This function retrieves the current WiFi mode of the ESP8266.

```cpp
WiFiMode_t getMode()
```

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

### Get ESP8266 Flash Chip ID

Source: https://arduino-esp8266.readthedocs.io/en/latest/libraries.html

Retrieves the ID of the flash chip as a 32-bit integer.

```cpp
ESP.getFlashChipId();
```

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

### Initialize Wi-Fi Connection

Source: https://arduino-esp8266.readthedocs.io/en/latest/esp8266wifi/readme.html

This code initializes the Wi-Fi connection process by calling the WiFi.begin() method with the network name and password.

```C++
WiFi.begin("network-name", "pass-to-network");

```

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

### Set up Open Soft Access Point

Source: https://arduino-esp8266.readthedocs.io/en/latest/esp8266wifi/soft-access-point-class.html

Use this overload to quickly set up an open Wi-Fi network with a specified SSID.

```cpp
WiFi.softAP(ssid)
```

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

### Get ESP8266 Chip ID

Source: https://arduino-esp8266.readthedocs.io/en/latest/libraries.html

Retrieves the unique 32-bit integer ID of the ESP8266 chip.

```cpp
ESP.getChipId();
```

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

### Get ESP8266 Free Heap Size

Source: https://arduino-esp8266.readthedocs.io/en/latest/libraries.html

Returns the amount of free memory available on the heap.

```cpp
ESP.getFreeHeap();
```

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

### Start Smart Config

Source: https://arduino-esp8266.readthedocs.io/en/latest/esp8266wifi/station-class.html

Begins the Smart Config process by sniffing for special packets containing the SSID and password of the desired Access Point. Returns true on success, false otherwise.

```cpp
beginSmartConfig()
```

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

### Get ESP8266 Reset Reason

Source: https://arduino-esp8266.readthedocs.io/en/latest/libraries.html

Retrieves a human-readable string indicating the reason for the last reset.

```cpp
ESP.getResetReason();
```

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

### Get ESP8266 Sketch MD5

Source: https://arduino-esp8266.readthedocs.io/en/latest/libraries.html

Returns a lowercase string containing the MD5 hash of the current sketch.

```cpp
ESP.getSketchMD5();
```

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

### Create a Directory

Source: https://arduino-esp8266.readthedocs.io/en/latest/filesystem.html

Creates a new directory at the specified absolute path. Returns true on success.

```C++
LittleFS.mkdir(path)
```

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

### Get ESP8266 CPU Frequency

Source: https://arduino-esp8266.readthedocs.io/en/latest/libraries.html

Returns the current CPU frequency in MHz as an unsigned 8-bit integer.

```cpp
ESP.getCpuFreqMHz();
```

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

### Get WiFi PHY Mode

Source: https://arduino-esp8266.readthedocs.io/en/latest/esp8266wifi/generic-class.html

Retrieves the current WiFi radio's physical layer mode.

```cpp
WiFiPhyMode_t  getPhyMode (WiFiPhyMode_t mode)
```

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

### Example: Printing Connected Station Count

Source: https://arduino-esp8266.readthedocs.io/en/latest/esp8266wifi/soft-access-point-class.html

Prints the number of stations currently connected to the soft-AP to the serial monitor.

```cpp
Serial.printf("Stations connected to soft-AP = %d\n", WiFi.softAPgetStationNum());
```

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

### Accept Incoming WiFi Client

Source: https://arduino-esp8266.readthedocs.io/en/latest/esp8266wifi/server-examples.html

In the main loop, accept new client connections to the server. This function blocks until a client connects.

```cpp
void loop()
{
  WiFiClient client = server.accept();
  if (client)
  {
    // we have a new client sending some request
  }
}
```

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

### mkdir

Source: https://arduino-esp8266.readthedocs.io/en/latest/filesystem.html

Creates a directory at the specified path.

```APIDOC
## mkdir

Creates a directory.

### Method

LittleFS.mkdir(path)

### Parameters

- **path** (string) - The path for the directory to create.

### Returns

- **boolean**: `true` if the directory creation succeeded, `false` otherwise.
```

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

### File Object Methods

Source: https://arduino-esp8266.readthedocs.io/en/latest/filesystem.html

Methods for interacting with individual files, including seeking, getting size, name, and status.

```APIDOC
## File Object

### Description
The `File` object is returned by `SPIFFS/LittleFS.open()` and `dir.openFile()`. It provides methods for file manipulation and information retrieval.

### Methods
* **seek(offset, mode)**: Moves the file position indicator. `mode` can be `SeekSet`, `SeekCur`, or `SeekEnd`. Returns `true` on success.
* **position()**: Returns the current position within the file in bytes.
* **size()**: Returns the total size of the file in bytes.
* **name()**: Returns the short name of the file (without path).
* **fullName()**: Returns the full path of the file.
* **getLastWrite()**: Returns the last write time of the file (valid for read-only mode).
* **getCreationTime()**: Returns the creation time of the file, if available.
* **isFile()**: Returns `true` if the object represents a file.
* **isDirectory()**: Returns `true` if the object represents a directory.
* **close()**: Closes the file. No further operations should be performed on the `File` object after this.
* **openNextFile()**: Opens the next file in the directory (use `Dir::openFile` for new code). Only valid if `File.isDirectory()` is true.

### Example Usage
```cpp
File file = LittleFS.open("/myFile.txt", "r");
if (file) {
    Serial.println(file.size());
    file.seek(10, SeekSet);
    Serial.println(file.position());
    file.close();
}
```
```

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

### Initialize Git Submodules (Windows)

Source: https://arduino-esp8266.readthedocs.io/en/latest/installing.html

Initialize and update git submodules to fetch external libraries required by the ESP8266 core. This step is crucial for build success.

```bash
cd %USERPROFILE%\Documents\Arduino\hardware\esp8266com\esp8266
git submodule update --init

```

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

### subnetMask

Source: https://arduino-esp8266.readthedocs.io/en/latest/esp8266wifi/station-class.html

Gets the subnet mask of the station's interface. The module should be connected to the access point to obtain this information.

```APIDOC
## subnetMask

### Description
Get the subnet mask of the station’s interface.

### Method Signature
```cpp
WiFi.subnetMask()
```

### Notes
Module should be connected to the access point to obtain the subnet mask.
```

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

### Get ESP8266 Sketch Size

Source: https://arduino-esp8266.readthedocs.io/en/latest/libraries.html

Returns the size of the currently uploaded sketch in bytes as an unsigned 32-bit integer.

```cpp
ESP.getSketchSize();
```

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

### Get Gateway IP Address

Source: https://arduino-esp8266.readthedocs.io/en/latest/esp8266wifi/station-class.html

Retrieves the IP address of the gateway. Requires the module to be connected to an access point.

```cpp
WiFi.gatewayIP()
```

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

### Separate Debug and Production Build Options

Source: https://arduino-esp8266.readthedocs.io/en/latest/faq/a06-global-build-options.html

This updated global header file demonstrates how to define separate build options for debug and production environments using distinct `/*@create-file:build.opt@` comment blocks. This allows for different compiler flags and defines based on the build type.

```arduino
/*@create-file:build.opt:debug@
// Debug build options
-DMYTITLE1="\"Running on \""
-DUMM_STATS_FULL=1

//-fanalyzer

// Removing the optimization for "sibling and tail recursive calls" may fill
// in some gaps in the stack decoder report. Preserves the stack frames
// created at each level as you call down to the next.
-fno-optimize-sibling-calls
*/

/*@create-file:build.opt@
// Production build options
-DMYTITLE1="\"Running on \""
-DUMM_STATS_FULL=1
-O3
*/

#ifndef LOWWATERMARK_INO_GLOBALS_H
#define LOWWATERMARK_INO_GLOBALS_H

#if defined(__cplusplus)
#define MYTITLE2 "Empty"
#endif

#if !defined(__cplusplus) && !defined(__ASSEMBLER__)
#define MYTITLE2 "Full"
#endif

#ifdef DEBUG_ESP_PORT
// Global Debug defines
// ...
#else
// Global Production defines
// ...
#endif

#endif

```

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

### Manual Signing - C++ Declarations and Setup

Source: https://arduino-esp8266.readthedocs.io/en/latest/ota_updates/readme.html

Includes C++ code snippets for setting up BearSSL for signature validation within the main code. This involves declaring a public key, hash object, and signing verifier.

```cpp
<in globals>
BearSSL::PublicKey signPubKey( ... key contents ... );
BearSSL::HashSHA256 hash;
BearSSL::SigningVerifier sign( &signPubKey );
... 
<in setup()>
Update.installSignature( &hash, &sign );
```

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

### Initialize Git Submodules

Source: https://arduino-esp8266.readthedocs.io/en/latest/installing.html

Initialize submodules to fetch external libraries required for building the ESP8266 core. This step is crucial to avoid build failures when including common libraries.

```bash
cd esp8266
git submodule update --init

```

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

### Get ESP8266 Free Sketch Space

Source: https://arduino-esp8266.readthedocs.io/en/latest/libraries.html

Returns the remaining free space for the sketch in bytes as an unsigned 32-bit integer.

```cpp
ESP.getFreeSketchSpace();
```

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

### Get ESP8266 Heap Fragmentation Metric

Source: https://arduino-esp8266.readthedocs.io/en/latest/libraries.html

Returns a metric indicating the fragmentation of the heap. A value over 50% is considered problematic.

```cpp
ESP.getHeapFragmentation();
```

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

### Get WiFi Network Channel

Source: https://arduino-esp8266.readthedocs.io/en/latest/esp8266wifi/scan-class.html

Retrieves the channel of a discovered WiFi network. The networkItem is a zero-based index of the scanned network.

```cpp
WiFi.channel(networkItem)
```

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

### Configure Flash Map Support

Source: https://arduino-esp8266.readthedocs.io/en/latest/filesystem.html

Enable dynamic flash map configuration at boot time by defining FLASH_MAP_SUPPORT. This allows the sketch to select the filesystem configuration based on the flash chip size.

```c++
#define FLASH_MAP_SUPPORT 1
```

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

### Get Full File Path

Source: https://arduino-esp8266.readthedocs.io/en/latest/filesystem.html

Retrieve the complete path to the file within the filesystem. This includes the directory structure leading to the file.

```cpp
// Filesystem:
//   testdir/
//           file1
Dir d = LittleFS.openDir("testdir/");
File f = d.openFile("r");
// f.name() == "file1", f.fullName() == "testdir/file1"
```

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

### Using FPSTR with a Global Flash String

Source: https://arduino-esp8266.readthedocs.io/en/latest/PROGMEM.html

Demonstrates how to define a string in PROGMEM and then use `FPSTR()` to cast it to `__FlashStringHelper` for printing.

```c++
static const char xyz[] PROGMEM = "This is a string stored in flash";
Serial.println(FPSTR(xyz));
```

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

### Include UDP Libraries

Source: https://arduino-esp8266.readthedocs.io/en/latest/esp8266wifi/udp-examples.html

Include the ESP8266WiFi.h and WiFiUdp.h libraries for Wi-Fi and UDP functionality.

```cpp
#include <ESP8266WiFi.h>
#include <WiFiUdp.h>

```

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

### Get Short File Name

Source: https://arduino-esp8266.readthedocs.io/en/latest/filesystem.html

Retrieve the base name of the file, without any path components. Useful for displaying or processing just the filename itself.

```cpp
String name = file.name();
```