hal-avr0-twi_soft - AVR0 Software TWI Hardware Abstraction

The hal-avr0-twi_soft is a lightweight software-twi hardware abstraction library for AVR0 microcontrollers. It provides a clean interface for software-twi 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 AVR0 targets.

Features

• Software-TWI master configuration for AVR0 devices.
• Software-TWI master communication for AVR0 devices.
• Encapsulation of low-level register access.
• Compact and reusable API for embedded projects.
• Foundation for layered HAL architectures.

The hal-avr0-twi_soft library reduces coupling by providing a focused interface for essential software-twi system services. This improves portability inside a project, keeps startup code organized, and makes higher-level modules easier to maintain.

File Structure

hal/
├── common/
|   ├── defines/
|   |   └── TWI_defines.h
|   └── enums/
|       └── TWI_enums.h
└── avr0/
    └── twi/
        ├── twi_soft.c
        └── twi_soft.h

Downloads

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

Type	File	Description
Library	zip / tar	AVR0 twi_soft 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/avr0
git clone https://github.com/0x007E/hal-avr0-twi_soft.git ./hal/avr0
mv ./hal/avr0/hal-avr0-twi_soft ./hal/avr0/twi

Using as git submodule

git submodule add https://github.com/0x007E/hal-common.git        ./hal/common
git submodule add https://github.com/0x007E/hal-avr0-twi_soft.git ./hal/avr0/twi

Programming

Additional parameters like twi clock speed, used pins and many more can be setup in the header file. A user friendly description can be found here.

#include "../hal/avr0/twi/twi_soft.h"

int main(void)
{
	twi_soft_init();

    while (1)
    {
        TWI_Error error = TWI_None;

        // TWI-WRITE command
        twi_soft_start();
	
        error |= twi_soft_address(high_byte, TWI_Write);
        error |= twi_soft_set(middle_byte);
        error |= twi_soft_set(low_byte);

        twi_soft_stop();

        // TWI-READ command
        twi_soft_start();
	
        error |= twi_soft_address(high_byte, TWI_Read);
        error |= twi_soft_get(data, TWI_ACK);
        error |= twi_soft_get(data, TWI_NACK);

        twi_soft_stop();
    }
}

Additional Information

Type	Link	Description
AVR0-Series	pdf	megaAVR® 0-series family datasheet

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R. GAECHTER