@foxglove/ros2

> _Standalone TypeScript implementation of the ROS 2 protocol built on @foxglove/rtps_


Usage

A simple listener that is compatible with the ROS 2 "talker" example application.

``Typescript
import { parse as parseMsgDef } from "@foxglove/rosmsg";
import { toString as timeString } from "@foxglove/rostime";
import { RosNode } from "@foxglove/ros2";
import { getNetworkInterfaces, UdpSocketNode } from "@foxglove/ros2/nodejs";

async function main() {
const ros = new RosNode({
name: "listener",
udpSocketCreate: UdpSocketNode.Create,
getNetworkInterfaces,
// log: console, // Enable this for verbose console debugging
});

await ros.start();

// Create a message definition for the std_msgs/msg/String type
const msgDefinition = parseMsgDef("string data", { ros2: true });

// Subscribe to the /chatter topic
const subscription = ros.subscribe({
topic: "/chatter",
dataType: "std_msgs/msg/String",
msgDefinition,
});
subscription.on("message", (timestamp, msg, _data, _publisher) => {
const strMsg = msg as { data: string };
console.log([INFO] [${timeString(timestamp)}] [listener]: I heard: [${strMsg.data}]);
});

// Listen for Ctrl+C to stop
process.on("SIGINT", () => void shutdown(ros));

// Wait for Ctrl+C
process.stdin.resume();
}

async function shutdown(ros: RosNode) {
await ros.shutdown();
process.exit();
}

void main();
`

Notes

Receiving large (>256KB) messages not be possible with the default Linux networking receive buffer size of 256KB, depending on CPU speed / contention / network speed / many factors. Linux users should set the following sysctls:

`
sudo sysctl -w net.core.rmem_max=26214400
sudo sysctl -w net.core.rmem_default=26214400
sudo sysctl -w net.ipv4.udp_mem=26214400
`

Or permanently in /etc/sysctl.conf:

`
net.core.rmem_max=26214400
net.core.rmem_default=26214400
net.ipv4.udp_mem=26214400
`

$3

yarn test

License

@foxglove/ros2 is licensed under MIT License.

Releasing

1. Run yarn version --[major|minor|patch] to bump version
2. Run git push && git push --tags` to push new tag
3. GitHub Actions will take care of the rest