This is the description of the JavaScript API bindings for the Distance US Bricklet. General information and technical specifications for the Distance US Bricklet are summarized in its hardware description.
An installation guide for the JavaScript API bindings is part of their general description.
The example code below is Public Domain (CC0 1.0).
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 | var Tinkerforge = require('tinkerforge');
var HOST = 'localhost';
var PORT = 4223;
var UID = 'jAw'; // Change to your UID
var ipcon = new Tinkerforge.IPConnection(); // Create IP connection
var dist = new Tinkerforge.BrickletDistanceUS(UID, ipcon); // Create device object
ipcon.connect(HOST, PORT,
function(error) {
console.log('Error: '+error);
}
); // Connect to brickd
// Don't use device before ipcon is connected
ipcon.on(Tinkerforge.IPConnection.CALLBACK_CONNECTED,
function(connectReason) {
// Get current distance value
dist.getDistanceValue(
function(distance) {
console.log('Distance: '+distance);
},
function(error) {
console.log('Error: '+error);
}
);
}
);
console.log("Press any key to exit ...");
process.stdin.on('data',
function(data) {
ipcon.disconnect();
process.exit(0);
}
);
|
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 | var Tinkerforge = require('tinkerforge');
var HOST = 'localhost';
var PORT = 4223;
var UID = 'jAw'; // Change to your UID
var ipcon = new Tinkerforge.IPConnection(); // Create IP connection
var dist = new Tinkerforge.BrickletDistanceUS(UID, ipcon); // Create device object
ipcon.connect(HOST, PORT,
function(error) {
console.log('Error: '+error);
}
); // Connect to brickd
// Don't use device before ipcon is connected
ipcon.on(Tinkerforge.IPConnection.CALLBACK_CONNECTED,
function(connectReason) {
// Set Period for distance callback to 0.2s (200ms)
// Note: The callback is only called every 200ms if the
// distance has changed since the last call!
dist.setDistanceCallbackPeriod(200);
}
);
// Register distance callback
dist.on(Tinkerforge.BrickletDistanceUS.CALLBACK_DISTANCE,
// Callback function for distance value
function(distance) {
console.log('Distance: '+distance);
}
);
console.log("Press any key to exit ...");
process.stdin.on('data',
function(data) {
ipcon.disconnect();
process.exit(0);
}
);
|
Download (ExampleThreshold.js)
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 | var Tinkerforge = require('tinkerforge');
var HOST = 'localhost';
var PORT = 4223;
var UID = 'jAw'; // Change to your UID
var ipcon = new Tinkerforge.IPConnection(); // Create IP connection
var dist = new Tinkerforge.BrickletDistanceUS(UID, ipcon); // Create device object
ipcon.connect(HOST, PORT,
function(error) {
console.log('Error: '+error);
}
); // Connect to brickd
// Don't use device before ipcon is connected
ipcon.on(Tinkerforge.IPConnection.CALLBACK_CONNECTED,
function(connectReason) {
// Get threshold callbacks with a debounce time of 10 seconds (10000ms)
dist.setDebouncePeriod(10000);
// Configure threshold for "smaller than 200"
dist.setDistanceCallbackThreshold('<', 200, 0);
// Set Period for distance callback to 0.2s (200ms)
// Note: The callback is only called every 200ms if the
// distance has changed since the last call!
dist.setDistanceCallbackPeriod(200);
}
);
// Register threshold reached callback
dist.on(Tinkerforge.BrickletDistanceUS.CALLBACK_DISTANCE_REACHED,
// Callback for distance value smaller than 200
function(distance) {
console.log('Distance value is smaller than 200: '+distance);
}
);
console.log("Press any key to exit ...");
process.stdin.on('data',
function(data) {
ipcon.disconnect();
process.exit(0);
}
);
|
Download (ExampleSimple.html), Test (ExampleSimple.html)
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 | <!DOCTYPE html>
<html>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<head>
<title>Tinkerforge | JavaScript Example</title>
</head>
<body>
<div style="text-align:center;">
<h1>Distance US Bricklet Simple Example</h1>
<p>
<input value="localhost" id="host" type="text" size="20">:
<input value="4280" id="port" type="text" size="5">,
<input value="uid" id="uid" type="text" size="5">
<input value="Start Example" id="start" type="button" onclick="startExample();">
</p>
<p>
<textarea id="text" cols="80" rows="24" style="resize:none;"
>Press "Start Example" to begin ...</textarea>
</p>
<div>
<script src="./Tinkerforge.js" type='text/javascript'></script>
<script type='text/javascript'>
var ipcon;
var textArea = document.getElementById("text");
function startExample() {
textArea.value = "";
var HOST = document.getElementById("host").value;
var PORT = parseInt(document.getElementById("port").value);
var UID = document.getElementById("uid").value;
if(ipcon !== undefined) {
ipcon.disconnect();
}
ipcon = new Tinkerforge.IPConnection(); // Create IP connection
var dist = new Tinkerforge.BrickletDistanceUS(UID, ipcon); // Create device object
ipcon.connect(HOST, PORT,
function(error) {
textArea.value += 'Error: '+error+ '\n';
}
); // Connect to brickd
// Don't use device before ipcon is connected
ipcon.on(Tinkerforge.IPConnection.CALLBACK_CONNECTED,
function(connectReason) {
// Get current distance value
dist.getDistanceValue(
function(distance) {
textArea.value += 'Distance: '+distance+'\n';
},
function(error) {
textArea.value += 'Error: '+error+'\n';
}
);
}
);
}
</script>
</body>
</html>
|
Download (ExampleCallback.html), Test (ExampleCallback.html)
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 | <!DOCTYPE html>
<html>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<head>
<title>Tinkerforge | JavaScript Example</title>
</head>
<body>
<div style="text-align:center;">
<h1>Distance US Bricklet Callback Example</h1>
<p>
<input value="localhost" id="host" type="text" size="20">:
<input value="4280" id="port" type="text" size="5">,
<input value="uid" id="uid" type="text" size="5">
<input value="Start Example" id="start" type="button" onclick="startExample();">
</p>
<p>
<textarea id="text" cols="80" rows="24" style="resize:none;"
>Press "Start Example" to begin ...</textarea>
</p>
<div>
<script src="./Tinkerforge.js" type='text/javascript'></script>
<script type='text/javascript'>
var ipcon;
var textArea = document.getElementById("text");
function startExample() {
textArea.value = "";
var HOST = document.getElementById("host").value;
var PORT = parseInt(document.getElementById("port").value);
var UID = document.getElementById("uid").value;
if(ipcon !== undefined) {
ipcon.disconnect();
}
ipcon = new Tinkerforge.IPConnection(); // Create IP connection
var dist = new Tinkerforge.BrickletDistanceUS(UID, ipcon); // Create device object
ipcon.connect(HOST, PORT,
function(error) {
textArea.value += 'Error: '+error+ '\n';
}
); // Connect to brickd
// Don't use device before ipcon is connected
ipcon.on(Tinkerforge.IPConnection.CALLBACK_CONNECTED,
function(connectReason) {
// Set Period for distance callback to 0.2s (200ms)
// Note: The callback is only called every 200ms if the
// distance has changed since the last call!
dist.setDistanceCallbackPeriod(200);
}
);
// Register distance callback
dist.on(Tinkerforge.BrickletDistanceUS.CALLBACK_DISTANCE,
// Callback function for distance value
function(distance) {
textArea.value += 'Distance: '+distance;
textArea.value += '\n';
textArea.scrollTop = textArea.scrollHeight;
}
);
}
</script>
</body>
</html>
|
Download (ExampleThreshold.html), Test (ExampleThreshold.html)
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 | <!DOCTYPE html>
<html>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<head>
<title>Tinkerforge | JavaScript Example</title>
</head>
<body>
<div style="text-align:center;">
<h1>Distance US Bricklet Threshold Example</h1>
<p>
<input value="localhost" id="host" type="text" size="20">:
<input value="4280" id="port" type="text" size="5">,
<input value="uid" id="uid" type="text" size="5">
<input value="Start Example" id="start" type="button" onclick="startExample();">
</p>
<p>
<textarea id="text" cols="80" rows="24" style="resize:none;"
>Press "Start Example" to begin ...</textarea>
</p>
<div>
<script src="./Tinkerforge.js" type='text/javascript'></script>
<script type='text/javascript'>
var ipcon;
var textArea = document.getElementById("text");
function startExample() {
textArea.value = "";
var HOST = document.getElementById("host").value;
var PORT = parseInt(document.getElementById("port").value);
var UID = document.getElementById("uid").value;
if(ipcon !== undefined) {
ipcon.disconnect();
}
ipcon = new Tinkerforge.IPConnection(); // Create IP connection
var dist = new Tinkerforge.BrickletDistanceUS(UID, ipcon); // Create device object
ipcon.connect(HOST, PORT,
function(error) {
textArea.value += 'Error: '+error+ '\n';
}
); // Connect to brickd
// Don't use device before ipcon is connected
ipcon.on(Tinkerforge.IPConnection.CALLBACK_CONNECTED,
function(connectReason) {
// Get threshold callbacks with a debounce time of 10 seconds (10000ms)
dist.setDebouncePeriod(10000);
// Configure threshold for "smaller than 200"
dist.setDistanceCallbackThreshold('<', 200, 0);
// Set Period for distance callback to 0.2s (200ms)
// Note: The callback is only called every 200ms if the
// distance has changed since the last call!
dist.setDistanceCallbackPeriod(200);
}
);
// Register threshold reached callback
dist.on(Tinkerforge.BrickletDistanceUS.CALLBACK_DISTANCE_REACHED,
// Callback for distance value smaller than 200
function(distance) {
textArea.value += 'Distance value is smaller than 200: '+distance;
textArea.value += '\n';
textArea.scrollTop = textArea.scrollHeight;
}
);
}
</script>
</body>
</html>
|
Generally, every method of the JavaScript bindings can take two optional parameters, returnCallback and errorCallback. These are two user defined callback functions. The returnCallback is called with the return values as parameters, if the method returns something. The errorCallback is called with an error code in case of an error. The error code can be one of the following values:
The namespace for the JavaScript bindings is Tinkerforge.*.
Parameters: |
|
---|
Creates an object with the unique device ID uid:
var distanceUS = new BrickletDistanceUS("YOUR_DEVICE_UID", ipcon);
This object can then be used after the IP Connection is connected (see examples above).
Callback: |
|
---|
Returns the current distance value measured by the sensor. The value has a range of 0 to 4095. A small value corresponds to a small distance, a big value corresponds to a big distance. The relation between the measured distance value and the actual distance is affected by the 5V supply voltage (deviations in the supply voltage result in deviations in the distance values) and is non-linear (resolution is bigger at close range).
If you want to get the distance value periodically, it is recommended to use the callback CALLBACK_DISTANCE and set the period with setDistanceCallbackPeriod().
Parameters: |
|
---|---|
Callback: | undefined |
Sets the length of a moving averaging for the distance value.
Setting the length to 0 will turn the averaging completely off. With less averaging, there is more noise on the data.
The range for the averaging is 0-100.
The default value is 20.
Callback: |
|
---|
Returns the length moving average as set by setMovingAverage().
Return type: | [int, int, int] |
---|
Returns the version of the API definition (major, minor, revision) implemented by this API bindings. This is neither the release version of this API bindings nor does it tell you anything about the represented Brick or Bricklet.
Parameters: |
|
---|---|
Return type: | boolean |
Returns the response expected flag for the function specified by the function ID parameter. It is true if the function is expected to send a response, false otherwise.
For getter functions this is enabled by default and cannot be disabled, because those functions will always send a response. For callback configuration functions it is enabled by default too, but can be disabled by setResponseExpected(). For setter functions it is disabled by default and can be enabled.
Enabling the response expected flag for a setter function allows to detect timeouts and other error conditions calls of this setter as well. The device will then send a response for this purpose. If this flag is disabled for a setter function then no response is send and errors are silently ignored, because they cannot be detected.
See setResponseExpected() for the list of function ID constants available for this function.
Parameters: |
|
---|
Changes the response expected flag of the function specified by the function ID parameter. This flag can only be changed for setter (default value: false) and callback configuration functions (default value: true). For getter functions it is always enabled and callbacks it is always disabled.
Enabling the response expected flag for a setter function allows to detect timeouts and other error conditions calls of this setter as well. The device will then send a response for this purpose. If this flag is disabled for a setter function then no response is send and errors are silently ignored, because they cannot be detected.
The following function ID constants are available for this function:
Parameters: |
|
---|
Changes the response expected flag for all setter and callback configuration functions of this device at once.
Callback: |
|
---|
Returns the UID, the UID where the Bricklet is connected to, the position, the hardware and firmware version as well as the device identifier.
The position can be 'a', 'b', 'c' or 'd'.
The device identifier numbers can be found here. There is also a constant for the device identifier of this Bricklet.
Parameters: |
|
---|
Registers a callback with ID id to the function callback. The available IDs with corresponding function signatures are listed below.
Parameters: |
|
---|---|
Callback: | undefined |
Sets the period in ms with which the CALLBACK_DISTANCE callback is triggered periodically. A value of 0 turns the callback off.
CALLBACK_DISTANCE is only triggered if the distance value has changed since the last triggering.
The default value is 0.
Callback: |
|
---|
Returns the period as set by setDistanceCallbackPeriod().
Parameters: |
|
---|---|
Callback: | undefined |
Sets the thresholds for the CALLBACK_DISTANCE_REACHED callback.
The following options are possible:
Option | Description |
---|---|
'x' | Callback is turned off |
'o' | Callback is triggered when the distance value is outside the min and max values |
'i' | Callback is triggered when the distance value is inside the min and max values |
'<' | Callback is triggered when the distance value is smaller than the min value (max is ignored) |
'>' | Callback is triggered when the distance value is greater than the min value (max is ignored) |
The default value is ('x', 0, 0).
The following constants are available for this function:
Callback: |
|
---|
Returns the threshold as set by setDistanceCallbackThreshold().
The following constants are available for this function:
Parameters: |
|
---|---|
Callback: | undefined |
Sets the period in ms with which the threshold callbacks
are triggered, if the thresholds
keep being reached.
The default value is 100.
Callback: |
|
---|
Returns the debounce period as set by setDebouncePeriod().
Callbacks can be registered to receive time critical or recurring data from the device. The registration is done with the on() function of the device object. The first parameter is the callback ID and the second parameter the callback function:
distanceUS.on(BrickletDistanceUS.CALLBACK_EXAMPLE,
function (param) {
console.log(param);
}
);
The available constants with inherent number and type of parameters are described below.
Note
Using callbacks for recurring events is always preferred compared to using getters. It will use less USB bandwidth and the latency will be a lot better, since there is no round trip time.
Parameters: |
|
---|
This callback is triggered periodically with the period that is set by setDistanceCallbackPeriod(). The parameter is the distance value of the sensor.
CALLBACK_DISTANCE is only triggered if the distance value has changed since the last triggering.
Parameters: |
|
---|
This callback is triggered when the threshold as set by setDistanceCallbackThreshold() is reached. The parameter is the distance value of the sensor.
If the threshold keeps being reached, the callback is triggered periodically with the period as set by setDebouncePeriod().
This constant is used to identify a Distance US Bricklet.
The getIdentity() function and the CALLBACK_ENUMERATE callback of the IP Connection have a device_identifier parameter to specify the Brick's or Bricklet's type.