Eclipse zenoh C Client API

Eclipse zenoh is an extremely efficient and fault-tolerant Named Data Networking (NDN) protocol that is able to scale down to extremely constrainded devices and networks.

zenoh-pico targets constrained devices and offers a C API for pure clients, i.e., it does not support peer-to-peer communication. zenoh-pico can be easily tested against a zenoh router running in a Docker container (see https://github.com/eclipse-zenoh/zenoh#how-to-test-it).

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How to install it

The Eclipse zenoh-pico library is available as Debian, RPM, and tgz packages in the Eclipse zenoh-pico download area. Those packages are built using manylinux2010 x86-32 and x86-64 to be compatible with most of the Linux platforms. There are 2 kind of packages:

• libzenohpico: only contains the library file (.so)
• libzenohpico-dev: contains the zenoh-pico header files for development. Depends on libzenohpico package

For other platforms, you will need to clone and build the sources.

WARNING: Note that zenoh-pico has not been ported on Windows yet!

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How to build it

To build the zenoh-pico client API you need to ensure that cmake is available on your platform -- if not please install it.

Once the cmake dependency is satisfied, just do the following for CMake version 3 and higher:

-- CMake version 3 and higher --

$ cd /path/to/zenoh-pico
$ make
$ make install # on Linux use **sudo**

If you want to build with debug symbols set the BUILD_TYPE=Debugenvironment variable before to run make:

$ cd /path/to/zenoh-pico
$ BUILD_TYPE=Debug make
$ make install # on Linux use **sudo**

For those that still have CMake version 2.8, do the following commands:

$ cd /path/to/zenoh-pico
$ mkdir build
$ cd build
$ cmake -DCMAKE_BUILD_TYPE=Release ../cmake-2.8
$ make
$ make install # on Linux use **sudo**

How to build for microcontrollers

In order to manage and ease the process of building and deploying into a a variety of microcontrollers, PlatformIO can be used as a supporting platform.

Once the PlatformIO dependency is satisfied, follow the steps below for the tested micro controllers.

Zephyr

Note: tested with reel_board

A typical PlatformIO project for Zephyr framework must have the following structure:

project_dir
├── include
├── src
│    └── main.c
├── zephyr
│    ├── prj.conf
│    └── CMakeLists.txt
└── platformio.ini

To initialize this project structure, execute the following commands:

$ mkdir -p /path/to/project_dir
$ cd /path/to/project_dir
$ platformio init -b reel_board
$ platformio run

Include the CMakelist.txt and prj.conf in the project_dir/zephyr folder as shown in the structure above, and add zenoh-pico as a library by doing:

$ cp /path/to/zenoh-pico/docs/zephyr/reel_board/CMakelists.txt /path/to/project_dir/zephyr/
$ cp /path/to/zenoh-pico/docs/zephyr/reel_board/prj.conf /path/to/project_dir/zephyr/
$ ln -s /path/to/zenoh-pico /path/to/project_dir/lib/zenoh-pico

Finally, your code should go into project_dir/src/main.c (examples provided with zenoh-pico work out of the box with Zephyr).

To build and upload the code into the board, run the following command:

platformio run
platformio run -t upload

ESP32

Note: tested with az-delivery-devkit-v4 board

A typical PlatformIO project for ESP32 framework must have the following structure:

project_dir
├── include
├── src
│    └── main.ino
└── platformio.ini

To initialize this project structure, execute the following commands:

$ mkdir -p /path/to/project_dir
$ cd /path/to/project_dir
$ platformio init -b az-delivery-devkit-v4
$ platformio run

Add zenoh-pico as a library by doing:

$ ln -s /path/to/zenoh-pico /path/to/project_dir/lib/zenoh-pico

Finally, your code should go into project_dir/src/main.ino. Check the examples provided in ./examples/net/esp32 directory.

To build and upload the code into the board, run the following command:

platformio run
platformio run -t upload

Running the Examples

The simplest way to run some of the example is to get a Docker image of the zenoh network router (see http://zenoh.io/docs/getting-started/quick-test/) and then to run the examples on your machine.

Starting the zenoh Network Service

Assuming you've pulled the Docker image of the zenoh network router on a Linux host (to leverage UDP multicast scouting has explained here), then simply do:

$ docker run --init -net host eclipse/zenoh:master

To see the zenoh manual page, simply do:

$ docker run --init -net host eclipse/zenoh:master --help

Basic Pub/Sub Example

Assuming that (1) you are running the zenoh network router, and (2) you are under the build directory, do:

$ ./zn_sub

And on another shell, do:

$ ./zn_pub

Basic Eval/Query Example

Assuming you are running the zenoh network service, do:

$ ./zn_eval

And on another shell, do:

$ ./zn_query