vterm

A native iOS app for interacting with a ROS 2 network from an iPhone or iPad.

Cross-compiling the ROS 2 (Jazzy) stack for iOS was easily the most challenging part of this project, and that process is documented here.

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Features

• Publish — spin up a std_msgs/String publisher on any topic and send messages
• Subscribe — browse live topics on the network, tap one to subscribe (or type the topic), and echo the topic in real time

Architecture

The ROS 2 C++ stack (rclcpp, rmw_cyclonedds_cpp, and all dependencies) is cross-compiled for iOS arm64 and bundled as static libraries under libs/ (you will need to compile these yourself; the libraries are not provided. again, see the blog post). A thin C API (rosios.h / rosios.cpp) wraps rclcpp and is exposed to Swift via a bridging header.

vterm/
├── ROS/
│   ├── rosios.h          # C API boundary
│   ├── rosios.cpp        # rclcpp implementation
│   ├── ROSContext.swift  # singleton: rclcpp init, executor lifecycle
│   ├── ROSNode.swift     # node wrapper
│   ├── ROSPublisher.swift
│   ├── ROSSubscriber.swift
│   └── ROSSettings.swift # persisted peer config
├── ContentView.swift     # tab UI: Publish / Subscribe / Config
libs/                     # pre-built static .a files (compile yourself)
ROS2.xcconfig             # include paths and linker flags for the static libs

DDS / Discovery

iOS blocks multicast sockets, so the app uses unicast-only CycloneDDS discovery. Add the IP address or hostname of each peer in the Config tab before starting. The CYCLONEDDS_URI is constructed at runtime from these peers and the device's WiFi IP (en0).

Requirements

• Xcode 15+
• iOS 17+ deployment target
• The pre-built ROS 2 Jazzy static libraries placed under libs/ (see the blog post above for build instructions)
• Both the iOS device and the peer machine on the same WiFi network (make sure to disable cellular on the phone while running this, it will inevitably cause issues)