spi

hal-avr-mega-spi - AVR ATmega SPI Hardware Abstraction

The hal-avr-mega-spi is a lightweight spi hardware abstraction library for AVR ATmega microcontrollers. It provides a clean interface for spi initialization and communication while hiding direct register-level interaction from higher software layers. The library is intended for projects that want to separate low-level device startup code from application logic and establish a small, reusable system layer for AVR targets.

Features

• SPI master configuration for AVR ATmega devices.
• SPI master communication for AVR ATmega devices.
• Encapsulation of low-level register access.
• Compact and reusable API for embedded projects.
• Foundation for layered HAL architectures.

The hal-avr-mega-spi library reduces coupling by providing a focused interface for essential spi system services. This improves portability inside a project, keeps startup code organized, and makes higher-level modules easier to maintain.

File Structure

hal/
├── common/
|   ├── enums/
|   |   └── SPI_enums.h
|   └── macros/
|       └── PORT_macros.h
└── avr/
    └── spi/
        ├── spi.c
        └── spi.h

Downloads

The library can be downloaded (zip or tar), cloned or used as submodule in a project.

Type	File	Description
Library	zip / tar	AVR spi library

Using with git clone

mkdir -p ./hal/
git clone https://github.com/0x007E/hal-common.git ./hal
mv ./hal/hal-common ./hal/common
 
mkdir -p ./hal/avr
git clone https://github.com/0x007E/hal-avr-mega-spi.git ./hal/avr
mv ./hal/avr/hal-avr-mega-spi ./hal/avr/spi

Using as git submodule

git submodule add https://github.com/0x007E/hal-common.git   ./hal/common
git submodule add https://github.com/0x007E/hal-avr-mega-spi.git ./hal/avr/spi

Programming

Additional parameters like spi clock speed, prescaler, pin definitions and many more can be setup in the header file. A user friendly description can be found here.

#include "../hal/avr/spi/spi.h"
 
int main(void)
{
    spi_init(SPI_MSB, SPI_Rising, SPI_Rising);
 
    while (1)
    {
        spi_select(SPI_Enable);
 
        unsigned char data = 0x00;
        data = spi_transfer(data);
 
        spi_select(SPI_Disable);
    }
}

Additional Information

Type	Link	Description
AVR-Series	pdf	ATmega16A datasheet

---

R. GAECHTER