avr_io - nim register bindings and utilities for AVR microcontrollers

avr_io is a library written to make it easy to program AVR microcontrollers in nim.

The library has a focus on low/no runtime costs, and it offers:

• Type-safe register bindings for AVR microcontrollers and an ergonomic pin/port API.
• Interrupt service routine tagging, and interrupt-related utilities.
• Macro-based program memory storage support (aka progmem).
• Utilities for embedding data in elf sections, writing bootloaders.
• Partial support for peripherals for some chips (uart, timers, ports).

Any project using this library must use avr-gcc as its C backend.

NOTE: the contents of the library are experimental, APIs may break before a v1.0 release!

• avr_io - nim register bindings and utilities for AVR microcontrollers
  • Requirements
  • Support
  • Install
  • Testing
    • Using avr_io in unit tests
  • Documentation
  • License

Requirements

• nim >= 2.0.10
• avr-gcc and avr-libc installed on your machine and available in your path.

Support

The nim modules that offer IO register mappings and ISR definitions are generated using the atdf chips description files as a reference.

The library currently supports most attiny and atmega chips, except for ones from the avrxmega and avr1 families. The former uses the new Port API which is not currently supported by this library, while the latter devices are only supported at the assembler-level by avr-gcc.

Since this avr_io makes heavy usage of c codegen, avr1 devices are not planned to be supported.

For a full list of supported targets, you can run:

./scripts/supported.nims

Or to check if a specific chip is supported (e.g. atmega644):

./scripts/supported.nims atmega644

The library is currently tested with:

• avr-gcc 15.2.0
• binutils 2.45
• avr-libc 2.2.1

Install

nimble install avr_io

In order to compile a project with this library, please follow the setup instructions pointed out in the wiki.

Testing

Run the avr_io test suite by executing the following command:

nim r tests/test_compile

Using avr_io in unit tests

In case you want to perform unit tests on modules import avr_io, a special symbol must be defined when calling such tests, using --define:AVRIO_TESTING.

Documentation

There are three main documentation sources for this project:

• The wiki hosted within the avr_io GitHub page.
• The examples contained within the examples directory, that hosts a series of nimble projects ready to use and to be consulted, going quite thoroughly in detail on how to use the library.
• The in-comment documentation.

You can generate the documentation for this module and its submodules by running the following command from the root directory of the project:

nim doc --project --index:on -d:USING_ATMEGA328P --outdir:docs src/avr_io.nim

Note that you have to specify the microcontroller you are using, like when setting up the library.

License

This library is licensed under the BSD 3-Clause "New" or "Revised" License.