ROS Bridge Simple Keyboard
From wikidb
Contents
Overview
This is a rudimentary proof-of-concept test. Key presses are sometimes missed, the twist commands has too long an interval causing control latencies, and the coding style is poor. The code started with the Robot Webtools keyboardtelepjs/examples/keyboardteleop.html and diverged quickly from there. In the end it doesn't use the keyboardteleopjs library at all. See references below.
Run
In separate terminals.
roscore rosrun phidgets motor_control_hc roslaunch rosbridge_server rosbridge_websocket.launch
In browser
localhost/~eepp/keyboard_test.html
roslauanch Script
roslaunch floor_hugger teleop_bridge.launch
ROS_Bridge_RobotWebTools_Keyboard_Teleop#roslaunch_Script
Debug
Motor Test
Enter the following to make sure the motors turn.
rostopic pub -1 /cmd_vel geometry_msgs/Twist '[5,0,0]' '[0,0,0]'
Message Listen
rostopic echo /cmd_vel
Also
rostopic list rosnode list
References
JavaScript Test Page
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<link rel="stylesheet" type="text/css"
href="http://ajax.googleapis.com/ajax/libs/jqueryui/1.8/themes/base/jquery-ui.css" />
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.8.0/jquery.min.js"></script>
<script src="https://ajax.googleapis.com/ajax/libs/jqueryui/1.8.23/jquery-ui.min.js"></script>
<script src="http://cdn.robotwebtools.org/EventEmitter2/current/eventemitter2.min.js"></script>
<script src="http://cdn.robotwebtools.org/roslibjs/current/roslib.js"></script>
<script>
// ------ GLOBALS ------
// ------ Websocket ------
// Connect to ROS.
var ros = new ROSLIB.Ros
({
url : 'ws://localhost:9090'
});
ros.on('connection', function() {
console.log('Connected to websocket server.');
});
ros.on('error', function(error)
{
console.log('Error connecting to websocket server: ', error);
});
ros.on('close', function()
{
console.log('Connection to websocket server closed.');
});
// ------ move ------
// linearx: -100 to 100 precent
// rotatez: -100 to 100 percent
function move(linearx, rotatez)
{
// Create the velocity command
var cmdVel = new ROSLIB.Topic
({
ros : ros,
name : '/cmd_vel',
messageType : 'geometry_msgs/Twist'
});
// Create the twist message
var twist = new ROSLIB.Message
({
linear :
{
x : linearx / 20,
y : 0.0,
z : 0.0
},
angular :
{
x : 0.0,
y : 0.0,
z : rotatez / 20
}
});
// Publishing the twist message
cmdVel.publish(twist);
}
// ------ init ------
// Setup the slider when the page is loaded.
// Create the slide
function init()
{
$("#target").keypress( function(e) {
console.log("keypress" + " " + String.fromCharCode(e.which));
if (e.charCode == 87 || e.charCode == 119) {move ( 100, 0);} // w is forward
if (e.charCode == 83 || e.charCode == 115) {move (-100, 0);} // s is back
if (e.charCode == 68 || e.charCode == 100) {move ( 0, 100);} // d is right
if (e.charCode == 65 || e.charCode == 97) {move ( 0,-100);} // a is left
});
// Create a UI slider using JQuery UI.
$('#speed-slider').slider({
range : 'min',
min : 0,
max : 100,
value : 90,
slide : function(event, ui) {
// Publishing a Twist
move (ui.value, 0);
// Change the speed label.
$('#speed-label').html('Speed: ' + ui.value + '%');
}
});
// Set the initial speed.
$('#speed-label').html('Speed: ' + ($('#speed-slider').slider('value')) + '%');
move ($('#speed-slider').slider('value'), 0);
// clear the input field
$('#target').val('');
}
</script>
</head>
<body onload="init()">
<h1>Simple Keyboard Teleop 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>rosrun phidgets motor_control_hc</tt></li>
<li><tt>roslaunch rosbridge_server rosbridge_websocket.launch</tt></li>
<li>Use the slider to set motor linear x speed. Use 'w', 'a', 's', and 'd'
control direction</li>
</ol>
<form>
<fieldset>
<input id="target" type="text" value="Hello there">
</fieldset>
</form>
<div id="speed-label"></div>
<div id="speed-slider"></div>
</body>
</html>
