A toolbox of Arduino libraries for ESP8266 projects

After building several ESP8266 devices (math toys, a weather station, a Geiger counter, an RSS reader), I noticed every project re-needed the same small pieces: string handling, buzzer beeps, backlight dimming, WiFi connection, a boot splash. So I collected them into one repository of small, self-contained Arduino libraries: ESP8266-Functions-Common.

The libraries, one line each

• StringHelpers — Arduino String → char* conversion for the many display and serial APIs that refuse String. Sounds trivial; saves a debugging session every time.
• AlarmBeeper — short/long/off/pattern beeps on a buzzer, supporting both wiring polarities. Pattern playback is non-blocking, so the main loop keeps running while the buzzer plays.
• MathQuizGenerator — the question generator from the math toy series, extracted and reusable.
• BacklightController — ambient-light auto-dimming with hysteresis.
• WiFiMultiConnect — multi-network WiFi credentials with fallback, plus a WiFiManager portal mode so a device can be configured from a phone without re-flashing.
• WeatherDisplayHelpers — mapping weather condition codes to drawn icons.
• DeviceFleetClient — reports device status to a fleet server (with an iot.txt.example config file to copy).
• BootSplashBitmap — draws an XBM bitmap at boot; pairs with the GarfieldXBM icon pack.

Why "one library per folder" matters

Each library has its own README.md, library.properties and src/. In the Arduino IDE you can install just the ones you need, and each carries its own version number. The alternative — one giant "utils" library — works until you want to use one function and inherit ten dependencies.

Who uses this

Nearly every ESP8266 repository on my GitHub vendors these libraries — that is what "vendoring" means: copying the library source into the project so it builds standalone. The trade-off (updates do not propagate automatically) is worth it for devices that must compile years later.