How pinMode, digitalWrite and digitalRead Work | Microcontroller Tutorials
I/O Ports - Developer Help
AVR, C and Arduino - HackMD
Digital Input/Output Ports on AVR - Developer Help
GPIO Programming : Arduino / ATmega328p - Arduino
AVR basics: reading and writing GPIO pins - Machina Speculatrix
Programming Arduino and AVR Microcontrollers using the Assembly Language - DumbleBots
FABACADEMY
Weeks 11-12: AVR USB Devices and Programming
AVR basics: An introduction to AVR registers and macros - Machina Speculatrix
Programming AVR: a helpful header file with input/output macro functions - Tutorials - RobotShop Community
Macros for AVR Assembler Programming - Circuit Cellar
GNU C++ BlinkenLED Part 1 on the AVR (ATmega1284P with MikroElektronika EasyAVR6) and Atmel AVR Studio 5.1 - Pete Brown's 10rem.net
Smiley's Workshop 40: Digital I/O — Part 2 | Nuts & Volts Magazine
discussion07
GitHub - rixth/pin-defines: Generate a header file with useful macros for AVR development
MACRO concept of AVR Microcontroller - YouTube
embedded programming
Mixing C and Assembly in AVR GCC and AVR Studio 4 | µC eXperiment
AVR Coding Part 3: Digital Input | Unboxing Tomorrow
AVR basics: reading and writing GPIO pins - Machina Speculatrix
Avr Atmega Atmega1632 Gpio Ports And Registers | Avr Atmega
