roslib
Version:
The standard ROS Javascript Library
190 lines (161 loc) • 5.75 kB
HTML
<html>
<head>
<meta charset="utf-8" />
<script src="https://static.robotwebtools.org/EventEmitter2/current/eventemitter2.min.js"></script>
<script src="../build/roslib.js"></script>
<script>
// Connecting to ROS
// -----------------
var ros = new ROSLIB.Ros();
// If there is an error on the backend, an 'error' emit will be emitted.
ros.on('error', function(error) {
document.getElementById('connecting').style.display = 'none';
document.getElementById('connected').style.display = 'none';
document.getElementById('closed').style.display = 'none';
document.getElementById('error').style.display = 'inline';
console.log(error);
});
// Find out exactly when we made a connection.
ros.on('connection', function() {
console.log('Connection made!');
document.getElementById('connecting').style.display = 'none';
document.getElementById('error').style.display = 'none';
document.getElementById('closed').style.display = 'none';
document.getElementById('connected').style.display = 'inline';
});
ros.on('close', function() {
console.log('Connection closed.');
document.getElementById('connecting').style.display = 'none';
document.getElementById('connected').style.display = 'none';
document.getElementById('closed').style.display = 'inline';
});
// Create a connection to the rosbridge WebSocket server.
ros.connect('ws://localhost:9090');
// Publishing a Topic
// ------------------
// First, we create a Topic object with details of the topic's name and message type.
var cmdVel = new ROSLIB.Topic({
ros : ros,
name : '/cmd_vel',
messageType : 'geometry_msgs/Twist'
});
// Then we create the payload to be published. The object we pass in to ros.Message matches the
// fields defined in the geometry_msgs/Twist.msg definition.
var twist = new ROSLIB.Message({
linear : {
x : 0.1,
y : 0.2,
z : 0.3
},
angular : {
x : -0.1,
y : -0.2,
z : -0.3
}
});
// And finally, publish.
cmdVel.publish(twist);
//Subscribing to a Topic
//----------------------
// Like when publishing a topic, we first create a Topic object with details of the topic's name
// and message type. Note that we can call publish or subscribe on the same topic object.
var listener = new ROSLIB.Topic({
ros : ros,
name : '/listener',
messageType : 'std_msgs/String'
});
// Then we add a callback to be called every time a message is published on this topic.
listener.subscribe(function(message) {
console.log('Received message on ' + listener.name + ': ' + message.data);
// If desired, we can unsubscribe from the topic as well.
listener.unsubscribe();
});
// Calling a service
// -----------------
// First, we create a Service client with details of the service's name and service type.
var addTwoIntsClient = new ROSLIB.Service({
ros : ros,
name : '/add_two_ints',
serviceType : 'rospy_tutorials/AddTwoInts'
});
// Then we create a Service Request. The object we pass in to ROSLIB.ServiceRequest matches the
// fields defined in the rospy_tutorials AddTwoInts.srv file.
var request = new ROSLIB.ServiceRequest({
a : 1,
b : 2
});
// Finally, we call the /add_two_ints service and get back the results in the callback. The result
// is a ROSLIB.ServiceResponse object.
addTwoIntsClient.callService(request, function(result) {
console.log('Result for service call on ' + addTwoIntsClient.name + ': ' + result.sum);
});
// Advertising a Service
// ---------------------
// The Service object does double duty for both calling and advertising services
var setBoolServer = new ROSLIB.Service({
ros : ros,
name : '/set_bool',
serviceType : 'std_srvs/SetBool'
});
// Use the advertise() method to indicate that we want to provide this service
setBoolServer.advertise(function(request, response) {
console.log('Received service request on ' + setBoolServer.name + ': ' + request.data);
response['success'] = true;
response['message'] = 'Set successfully';
return true;
});
// Setting a param value
// ---------------------
ros.getParams(function(params) {
console.log(params);
});
// First, we create a Param object with the name of the param.
var maxVelX = new ROSLIB.Param({
ros : ros,
name : 'max_vel_y'
});
//Then we set the value of the param, which is sent to the ROS Parameter Server.
maxVelX.set(0.8);
maxVelX.get(function(value) {
console.log('MAX VAL: ' + value);
});
// Getting a param value
// ---------------------
var favoriteColor = new ROSLIB.Param({
ros : ros,
name : 'favorite_color'
});
favoriteColor.set('red');
favoriteColor.get(function(value) {
console.log('My robot\'s favorite color is ' + value);
});
</script>
</head>
<body>
<h1>Simple roslib Example</h1>
<p>Run the following commands in the terminal then refresh this page. Check the JavaScript
console for the output.</p>
<ol>
<li><tt>roscore</tt></li>
<li><tt>rostopic pub /listener std_msgs/String "Hello, World"</tt></li>
<li><tt>rostopic echo /cmd_vel</tt></li>
<li><tt>rosrun rospy_tutorials add_two_ints_server</tt></li>
<li><tt>roslaunch rosbridge_server rosbridge_websocket.launch</tt></li>
</ol>
<div id="statusIndicator">
<p id="connecting">
Connecting to rosbridge...
</p>
<p id="connected" style="color:#00D600; display:none">
Connected
</p>
<p id="error" style="color:#FF0000; display:none">
Error in the backend!
</p>
<p id="closed" style="display:none">
Connection closed.
</p>
</div>
</body>
</html>