work in progress

AVR for beginners

This repository is intended to contain detailed instructions on how to get started with programming Atmel AVR microcontrollers. It also contains a bunch of thoroughly documented and explained example projects.

Recommended websites:

http://mikrokontrolery.blogspot.com/p/spis-tresci.html (in Polish)

Running the code

This repository contains several folders. Each of those folders is a self-contained project that can be opened either in Atmel Studio or VS Code.

The fast & easy way to get started: wire everything up properly, connect the MCU (micro-controller unit) to your PC using a USBasp programmer.

Wire up your circuit correctly on the breadboard.
Connect the MCU to your PC using a USBasp programmer
cd <on of the project>, for example cd blink
make flash

What Makefiles do, explained

Compile

First, you need to compile a C source file to an .elf object file.

avr-gcc -mmcu=atmega8 -Wall -Os -o blink.elf blink.c -DF_CPU=1000000UL

DF_CPU=1000000UL sets F_CPU to 1MHz.

Convert .elf to .hex

To flash the MCU using USBasp programmer, you need a .hex file. It can be created out of the .elf file you generated in the previous step.

avr-objcopy -j .text -j .data -O ihex blink.elf blink.hex

Flash

Now it's time to run the code

avrdude -c usbasp -p m8 -e -U flash:w:blink.hex

Setup with VSCode

macOS

First things first: you need Homebrew.

Install avrdude - a small program used to flash AVR microcontrollers.

brew install avrdude
Install avr-gcc - an AVR-flavor of GNU GCC

brew tap osx-cross/avr

brew install avr-gcc
Install a C/C++ Extension for VSCode
To make VSCode's IntelliSense detect AVR header files, make the editor aware of them. For this, you'll need to know the exact version of your avr-gcc installation: brew ls avr-gcc

It prints a list which contains:

/usr/local/Cellar/avr-gcc/<version>/avr/include/

Copy that line, replacing with your version.

Now, in project root, create a .vscode folder. In it, create settings.json file with the following content:

Example (for avr-gcc v9.3.0 and using headers for ATmega8A)

{
  "C_Cpp.default.includePath": [" /usr/local/Cellar/avr-gcc/9.3.0/avr/include/"],
  "C_Cpp.default.defines": ["__AVR_ATmega8A__"]
}

Voilà, IntelliSense should work now.

Windows

coming soon (or never)

you can as well just use WSL

Setup with Atmel Studio (only on Windows)