Compiling ROS 2 interfaces

WARNING: These instructions are located in https://github.com/modular-ml/wrapyfi_ros2_interfaces

To run the Wrapyfi ROS 2 services and transmit audio messages, you need to compile the ROS 2 interfaces. ROS 2 must already be installed on your system, with all its build dependencies. You can find the installation instructions here or install using Robostack.

Prerequisites

ROS 2 Galactic/Humble
Python 3.6

Compiling

Copy the wrapyfi_ros2_interfaces folder to your ROS 2 workspace (assumed to be ~/ros2_ws).

# from the current directory 
cd ../
cp -r wrapyfi_ros2_interfaces ~/ros2_ws/src

Compile the ROS 2 interfaces:
```
cd ~/ros2_ws
colcon build --packages-select wrapyfi_ros2_interfaces
```
Note: If the wrong version of Python is used, the compilation will fail. Make sure that the correct version of cmake is used by modifying the cmake_minimum_required version in the ~/ros2_ws/src/wrapyfi_ros2_interfaces/CMakeLists.txt file:
```
# CMakeLists.txt
cmake_minimum_required(VERSION 3.5)
# ...
```
Replacing VERSION 3.5 with the correct version of cmake.
Source the ROS 2 workspace:
```
source ~/ros2_ws/install/setup.bash
```

Verify that the ROS 2 Native object service interface is compiled:

ros2 interface show wrapyfi_ros2_interfaces/srv/ROS2NativeObjectService

Which should output:

string request
---
string response

Verify that the ROS 2 Image service interface is compiled:

ros2 interface show wrapyfi_ros2_interfaces/srv/ROS2ImageService

Which should output:

string request
---
sensor_msgs/Image response
    std_msgs/Header header
        builtin_interfaces/Time stamp
            int32 sec
            uint32 nanosec
        string frame_id
                                 # Header frame_id should be optical frame of camera
                                 # origin of frame should be optical center of cameara
                                 # +x should point to the right in the image
                                 # +y should point down in the image
                                 # +z should point into to plane of the image
                                 # If the frame_id here and the frame_id of the CameraInfo
                                 # message associated with the image conflict
                                 # the behavior is undefined
    uint32 height
    uint32 width
    string encoding
                          # taken from the list of strings in include/sensor_msgs/image_encodings.hpp
    uint8 is_bigendian
    uint32 step
    uint8[] data

Verify that the ROS 2 Audio service interface is compiled:

ros2 interface show wrapyfi_ros2_interfaces/srv/ROS2AudioService

Which should output:

string request
---
wrapyfi_ros2_interfaces/ROS2AudioMessage response
   std_msgs/Header header
       builtin_interfaces/Time stamp
           int32 sec
           uint32 nanosec
       string frame_id
   uint32 chunk_size
   uint8 channels
   uint32 sample_rate
   string encoding
   uint8 is_bigendian
   uint32 bitrate
   string coding_format
   uint32 step
   uint8[] data

Run your Wrapyfi enabled script from the same terminal. Now you can use the REQ/REP pattern (server/client) in Wrapyfi [example], and transmit ROS 2 audio messages [example].