• Containers: Arrays, Bit Arrays, Linked Lists, Smart Pointers.
• Extended Input/Output: Use shift registers (e.g. 74HC595), multiplexers (e.g. 74HC4051, 74HC4067) and IO expanders as if they were normal Arduino IO pins.
• Hardware Utilities: Debounced buttons, long press buttons, double-click buttons, button matrices, filtered analog inputs, MCP23017 Rotary Encoders, LED ranges, MAX7219 displays and LED matrices.
• Filters: Exponential Moving Average filters, Hysteresis.
• Math functions: min and max functions instead of macros, functions for uniformly increasing the bit depth of signals, all C++ standard library functions, vectors, quaternions, Euler angles.
• Timing Utilities: Blink Without Delay-style timers.
• C++ STL Implementation (partial): Some useful parts of the C++ Standard Template Library, adapted to work on AVR Arduinos. Includes the <type_traits>, <algorithm>, <numeric>, <new>, <array>, <bitset>, <optional>, <cmath>, <complex>, <cstdlib>, <cstdint>, <tuple>, <memory> (std::unique_ptr), <initialize_list>, <utility> and <limits> headers, among others.

These utilities were originally part of the Control Surface library, and were split off to be used as a stand-alone library, or as a template for other libraries.

Libraries that use the Arduino Helpers library include:

• Arduino Filters: FIR, IIR filtering library
• Control Surface: library for creating MIDI Control Surfaces, with knobs and push buttons, LEDs, displays, etc.

The automatically generated Doxygen documentation for this library can be found here:
Documentation
Test coverage information can be found here:
Code Coverage
Arduino examples can be found here:
Examples

Download the repository as a ZIP archive by going to the home page of the repository and clicking the green Code button in the top right, then choosing “Download ZIP”.
Alternatively, click the following direct download link: https://github.com/tttapa/Arduino-Helpers/archive/refs/heads/master.zip

Open the Arduino IDE, and go to the Sketch > Include Library > Add .ZIP Library menu.
Then navigate to your downloads directory where you just downloaded the library.
Select it, and click Ok.

For each commit, the continuous integration tests compile the examples for the following boards:

• Arduino UNO
• Arduino Mega
• Arduino Leonardo
• Teensy 3.2
• Teensy 4.1
• Arduino Due
• Arduino Nano 33 IoT
• Arduino Nano 33 BLE
• Arduino Nano Every
• ESP8266
• ESP32
• Raspberry Pi Pico

This covers a very large part of the Arduino platform, and similar boards will also work (e.g. Arduino Nano, Arduino Mega, etc.).

If you have a board that's not supported, please open an issue and let me know!

The Arduino Due toolchain provided by Arduino is very old, and has some configuration problems. As a result, some math functions are not available.
There is nothing I can do about it in this library, it's a bug in the Arduino Due Core.

• a81bd1927298decc2ea3852fd2f00e8028c14b81
  Classes that make use of the SPI interface now require you to pass the SPI object as a constructor argument. This allows you to use SPI1 or SPI2 (if available for your hardware).