digitalWriteFast

Arduino library for faster digitalWrite() using direct port manipulation and macro for ease in pin assignments for constant pin numbers. It also provides faster pinMode() and digitalRead() functions as well as it adds a digitalToggleFast() function.

Available as Arduino library "digitalWriteFast".

This is a fork of the subtree https://github.com/watterott/Arduino-Libs/tree/master/digitalWriteFast.

If pin number is no compile time constant, or the platform is not supported, then the regular Arduino functions digitalWrite() etc. are called.

Use '#define pinNum 10' instead of int pinNum = 10;
Use 'const int pinNum 10' instead of int pinNum = 10;

Usage

Include the library: #include <digitalWriteFast.h>

Macro definitions:

digitalWriteFast(pinNum, state) (sets or clears pin/port faster)
pinModeFast(pinNum, mode) (sets pin/port as input or output faster)
digitalReadFast(pinNum)(reads the state of pin/port faster)
digitalToggleFast(pinNum)(toggles the state of pin/port faster)

Parameters:

pinNum is the number written on the Arduino board.
state is weather pin is to be set HIGH or LOW
mode is weather pin is to be set INPUT or OUTPUT or INPUT_PULLUP

Correct usage detection

Defining THROW_ERROR_IF_NOT_FAST would cause the macro to return an error during compilation, if the parameter is a variable and thus regular digital* functions must be called. This notifies the programmer the specific line where code is still slow.

Speed

For a 16 MHz Uno digitalWrite() is speed up from 5.8 �s to 125 ns, able to generate a 4 MHz signal instead of 86 kHz. More info in: /NOTES/NOTES.md

This is the waveform generated with the Timing example.

Compatibility

Arduino Uno, Nano etc.
Arduino Leonardo
Arduino Mega
Arduino with ATmega644 or Atmega644P chip
Arduino with ATmega4809 chip
Arduino with ATtiny chip
Adafruit Feather32u4 (must #define ADAFRUIT_AVR_FEATHER32U4)

Revision History

Version 1.1.0

Added TEENSYDUINO support.
Added THROW_ERROR_IF_NOT_FAST functionality.
Removed unnecessary compare > 0.
Added Guard && defined(__digitalPinToPINReg) etc.
Changed ifndef to if !defined().

Reference

This documentation is based on https://github.com/NicksonYap/digitalWriteFast/

vladimir-aubrecht/digitalWriteFast