lidar2ros for iPad

Publish iPad Pro LiDAR data & more in ROS 2.

Note: this repository only contains the source code & assets. To run the app, set up an Xcode project and import this.

Using the app

Display a simple help page in the app by pressing the help button in the lower right corner.

Hide or display the controls by pressing on the gear icon in the bottom left corner.

Setting up a remote rosbridge

For the data to be published in ROS 2, start ros2-web-bridge on a computer on the same network as your iPad (or any network reachable from your iPad).

Make sure ROS 2 is installed and sourced

Install ros2-web-bridge

$ git clone https://github.com/RobotWebTools/ros2-web-bridge.git
$ cd ros2-web-bridge
$ npm install

Run ros2-web-bridge
```
$ node bin/rosbridge.js
```

Connecting to the remote rosbridge

To connect to the remote rosbridge, in the app, enter the computer's IP and port (e.g. x.y.z.a:bcde, default ros2-web-bridge port is 9090) in the field next to Remote bridge. Once this is done, the switch next to the field will turn on and the app will connect to the remote rosbridge.

If the switch does not get flipped, it means the app could not connect. Check the IP & port and try again.

Publishing data

To publish data, turn on one of the other switches. The topic names can be changed using the corresponding text fields. Approximate publishing rates can be set using the corresponding steppers.

The table below lists the data available for publishing.

Description	Default topic name	Message type	Frame ID
Transforms¹
LiDAR depth map	`/ipad/depth`	`sensor_msgs/Image`	`ipad_camera`
LiDAR point cloud	`/ipad/pointcloud`	`sensor_msgs/PointCloud2`	`ipad`
Camera image	`/ipad/camera`	`sensor_msgs/Image`	`ipad_camera`

tf tree:
- map_ipad: iPad world origin
  - arkit_ref: iPad world origin (as ARKit reference wrt normal ROS reference)
    - ipad_camera: iPad camera
      - ipad: iPad in landscape mode

Generating the app icon assets

Xcode requires PNGs of various sizes for the app icon. These can easily be generated from the source file (lidar2ros_appicon.psd).

Make sure brew is installed, then install imagemagick:

% brew install imagemagick

To simply export the PSD file to a PNG (if you want a preview):

% convert 'lidar2ros_appicon.psd[0]' -resize 200x200 appicon.png

Run the provided script to generate all the required PNGs:

% ./gen_appicon_assets.sh

This script also generates the rounded app icon used at the top of this README.

License

This repository is released under the Apache License Version 2.0. See LICENSE.

Some 3rd party code is used & distributed under the MIT license. See LICENSE.3RD-PARTY.