Table of Contents
The vscpws_speedometerCelsius is a widget that can be used to display temperature values in an analog way. It is very easy to use and with just one line of code you can have a dynamic thermometer on your web page without any programming knowledge.
Construction of a vscpws_speedometerCelsius
vscpws_speedometerCelsius( username, // username passwordhash, // passwordhash, url, // url to VSCP websocket i/f canvasName, // Placeholder for widget widgetType, // Widget type vscpclass, // Event class 10/60/65 vscptype, // Event type sensorIndex,// Datacoding sensor index bNumeric, // Add numeric printout guid ) // GUID we are interested in
Username to logon to the websocket server.
Password hash to logon to the websocket server
Url to the websocket server. This typically is on the form
if SSL is used.
With all widgets having there own user/password/url specified for the websocket server it is possible to create web pages that control nodes/units/hardware that are located in different locations from the same page.
This is the name of the canvas element where the button should be placed. Typically this is defined on the form
<canvas id="mythermometer1" style="z-index: 1; position:absolute; left:100px; top:200px;" > Your browser does not support HTML5 Canvas. </canvas>
The id is the parameter that goes for the canvasName. This name is also used to create the instance name for the button and the name set is preceded with vscpws_. The canvas specifies the position for the widget, size is set by to the widgets size. Also z-order is possible to define so that objects can be placed behind, or partially behind each other to get nice visual effects.
This is the appearance of the widget. Zero i the default value. The following widgets is defined.
Type = 0 (Default)
This is the the VSCP class of the event we are interested in. This parameter should be set to one of the measurement events
VSCP_CLASS1_MEASUREMENT=10 (default), VSCP_CLASS1_DATA=15, VSCP_CLASS1_MEASUREMENT64=60 or VSCP_CLASS1_MEASUREZONE=65.
Set to -1 for don't care. Default is VSCP_CLASS1_MEASUREMENT.
This is the the VSCP type of the event we are interested in. This is normally set to VSCP_TYPE_MEASUREMENT_TEMPERATURE=6 , Set to -1 for don't care. Default is VSCP_TYPE_MEASUREMENT_TEMPERATURE=6.
This is the sensor index for the sensor in the device sending out the event. This information is part of the datacoding and can be a value 0,1,2,3,4,5,6,7. Set to -1 for don't care. Default=0.
Set to true to get a numerical representation of the temperature printed out as well. Default=true.
This can be used to match a specific GUID the event should come from. Default is “” meaning events from all sensors are of interest.
To use the vscpws_simpleTextEvent widget with events in class VSCP_CLASS1_MEASUREZONE and VSCP_CLASS1_SETVALUEZONE you may want to filter on more than sensorindex and guid. This method allows the extra info available in these classes to be checked as well.
setExtraParameters( index, // Index if applicable zone, // Zone if applicable subzone) // Subzone if applicable
This can be used to match a specific index. Default is -1 meaning don't care. Only VSCP_CLASS1_MEASUREZONE and VSCP_CLASS1_SETVALUEZONE have an index to check among the measurement classes.
This can be used to match a specific zone. Default is -1 meaning don't care. Only VSCP_CLASS1_MEASUREZONE and VSCP_CLASS1_SETVALUEZONE have a zone to check among the measurement classes.
This can be used to match a specific subzone. Default is -1 meaning don't care. Only VSCP_CLASS1_MEASUREZONE and VSCP_CLASS1_SETVALUEZONE have a subzone to check among the measurement classes.
With this method one can set a VSCP daemon variable that should be monitored with a specific interval. The current value of the variable will be written.
setMonitorVariable( variablename, // variable name interval ) // monitoring interval in milliseconds
The name for the VSCP daemon boolean variable.
The interval in milliseconds between variable reads. Set to zero to disable. Default=1000 (one second). To test try to set the variable name to “temp1” and issue
variable write temp1,,,20.5
variable write temp1,,,-12
in the VSCP daemon TCP/IP interface to see the change in your browser page.
Using the vscpws_speedometerCelsius widget
It's very easy to use this widget. Set up a data source that send temperature events on even intervals and then tell the temperature widget to look for them. As always you also need to position your widget somewhere and you do that in the canvas definition. A working example looks like this
<canvas id="mythermometer2" style="z-index: 1; position:absolute; left:200px; top:200px;" > Your browser does not support HTML5 Canvas. </canvas> var temp2 = new vscpws_speedometerCelsius( "ws://192.168.1.20:7681", "mythermometer2", 0, VSCP_CLASS1_MEASUREMENT, VSCP_TYPE_MEASUREMENT_TEMPERATURE, 2 ); temp2.setDecimals(0);
which displays measurement temperature data with a widget of type=0 from sensor 2 and the numerics are printed out by default. Also no decimals is printed out
No GUID is set here and should normally be added do distinguish data from different sources.