AVR/Arduino CMake Toolchain

A toolchain for compiling avr code and Arduino Sketches using CMake and CLion.

See ubirch-avr for an example where all variants are used.

Prerequisits

Install the toolchain:

For MacOS X the simplest way to get the toolchain is homebew:

brew tap larsimmisch/avr
brew install avr-binutils avr-gcc avr-libc avrdude
brew install cmake

If you want to be able to compile Arduino sketches you will also need the Arduino SDK and set the environment variable ARDUINO_SDK_PATH.

Building

The toolchain creates some functions to add static libs, sources and sketches to the build process:

static libraries

Create a directory where you have your libs (in separate sub directories). Just like in other CMake projects, each library needs a CMakeLists.txt like the following:

# tell the build system what to build
add_library(example-lib example-lib.c)
# for libraries also add the directory to the include path
target_include_directories(example-lib PUBLIC ${CMAKE_CURRENT_SOURCE_DIR})

avr targets

Create a directory where you store each of your targets in a separate subdirectory. Like the static libs, you will need a CMakeLists.txt in each of the targets directories. This time, we need to call one of the functions from the toolchain add_executable_avr() to declare the executable target:

# tell the build system what to build
add_executable_avr(example example.c)
# declare what dependencies this executable has
target_link_libraries(example example-lib)

Arduino sketches

Sketchs should also be put each in their own directory. Just like libs and targets they will need a CMakeLists.txt each which declares the target and dependencies. The core library is calles arduino-core. Other core libs like SoftwareSerial and Wire are also available. Unlike the Arduino IDE you need to declare each dependency.

If you use 3rd party libraries, like the Adafruit FONA library, just use the special function target_sketch_library() which takes the target, the name of the library and a git repository URL. The toolchain automatically clones (downloads) the library and adds the dependency. You will find the library then in a libraries directory next to your sketches.

# tell the buold system your sketch name and the sources
add_executable_avr(example-sketch example-sketch.cpp)

# we require a number of arduino libraries for this
# (they already depend on arduino-core, so we don't need it here)
# install these libraries and either copy them or create a link in the 'external' directory
target_link_libraries(example-sketch arduino-core SoftwareSerial)

# special external dependencies can be added like this and will be downloaded once (automatically)
# arguments: <target> <name> <git url>
target_sketch_library(example-sketch Adafruit_FONA_Library https://github.com/adafruit/Adafruit_FONA_Library)

Make

Your project needs also to be declared. Edit the example and put it into the top directory.

1. Edit CMakeLists.txt and set PROG_TYPE and PROG_DEV to your flash programmer and device.
2. follow the following procedure:

mkdir build
cd build
cmake ..
make eliza-flash monitor

To flash a target use the directory name with added -flash (example-flash).

Unless you make significant changes to the CMakeLists.txt you only need to run make in the build directory from now on.

LICENSE

Copyright 2015 ubirch GmbH (http://www.ubirch.com)

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.