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ARRIS Enterprises, Inc. Confidential Information

Front Panel Service Configuration

During startup, the Front Panel Service reads /etc/frontpanel_config.xml to determine how the STB's front panel should behave based on Information Object values and service-specific variables. For example, which LED shall be lit during standby and in which color.

Since KreaTV 5.0, the LEDs can only be controlled through this XML file.

KreaTV ships with a default configuration that can be overridden by adding kreatv-option-frontpanel-config:config=<custom config file.xml> to the boot image configuration file. The configuration XML file should conform to the DTD at the end of this page.

The Expression and Results elements

The <Expression> and <Result> elements in the configuration file allow flexible control of LEDs and segment display status.

The <Expression> element accepts a comma-separated list of variables to track. These variables can be generic Information Objects or variables that are specific for the Front Panel service.

  • $object is an Information Object named "object". The string shall only contain alphanumeric characters, dots, and underscores.
  • #variable is an internal Front Panel Service variable, and it can be one of the following:
Front Panel Service specific variables
Variable name Comment Values
PowerProfile The power state of the STB. See Power Management for more information.
  • active
  • active_standby
  • passive
WiFiState The state of the WiFi connection.
  • connected
  • connecting
  • inactive

<Result> elements are nested inside <Expression> elements. They also accept a comma-separated list of values that are matched against those defined in the parent <Expression>. When the state variables defined in the <Expression> match the values specified in a <Result>, the state defined inside the <Result> tag becomes active.

Two wildcards are supported. The * character in <Result> value strings matches any substring. The paneltype attribute supports, additionally, the ? wildcard, which matches a single arbitrary character.

When several <Result> elements are specified for an expression, the first match in the order of the <Result> elements will be the one used. If, for instance, "*" is given as the first <Result> then no other <Result> elements will be considered.

A small configuration example

Here is an example of a front panel configuration file showing how to configure the LED to display WiFi connection status. The LED will have steady green light if WiFi is not connected, pulsate in blue light when connecting to WiFi, and a steady blue light when connected. 


<?xml version="1.0"?>
<FrontPanelConfig version="2.1">
  <Panel type="*">
    <Expression value="#WiFiState">
      <Result value="connected">
        <RgbLed id="1" color1="#000040" color2="#000040"
                transitiontime="1000" holdtime="1000"/>
      </Result>
      <Result value="connecting">
        <RgbLed id="1" color1="#000080" color2="#000000"
                transitiontime="400" holdtime="0"/>
      </Result>
    </Expression>
    <Result value="*">
      <RgbLed id="1" color1="#005000" color2="#005000"
	      transitiontime="1000" holdtime="1000"/>
    </Result>
  </Panel>
</FrontPanelConfig>

The RgbLed and RgbColorAlias elements

The <RgbLed> element makes it possible to specify an animation between two RGB colors. An example of the kind of animation that is possible to achieve is depicted below:

The available attributes for the <RgbLed> element are as follows:

<RgbLed> element attributes
Attribute name Description
color1 An RGB triplet or RGB color alias name of the first active color.
color2 An RGB triplet or RGB color alias name of the second active color. If this color is specified to be the same as color1, the color will be kept static.
holdtime Specifies how long, in milliseconds, the current active color should stay stable before transitioning to the next color.
transitiontime Specifies how long, in milliseconds, the transition from the active color to the next color should take.

It is common that different set-top box models will produce different color nuances given the same RGB triplet. As an example, the RGB triplet used to produce a certain nuance of e.g. orange for set-top box model A might not be the same RGB triplet used to produce the very same nuance of orange on set-top box model B.

You can use the <RgbColorAlias> element to overcome this problem. This tag allows you to give a name to a specific RGB triplet and use that name when defining the front panel behavior. The tag accepts a paneltype attribute that makes it possible to define different RGB colors for different STB models, but all of them using the same color name. 


<RgbColorAlias name="Red-Faint" color="#110000" paneltype="vip43?2"/>
<RgbColorAlias name="Red-Faint" color="#1F0000" paneltype="vip4344"/>

The example above defines two slightly different RGB triplets for the color Red-Faint. By referring to this color by name in the rest of the configuration, you can compensate for the different color tints produced by the different STB models.

Front panels with RGB LEDs provide RCU input feedback by producing a pulse in color intensity. Color hue is kept, but light intensity is increased momentarily and gradually faded back to its original state. The concept is illustrated in the image below:

When customizing RGB LED colors, it is recommended to use medium intensities to leave some headroom for RCU feedback to be noticeable.

RGB LED colors available during passive standby may be limited by hardware capabilities.

Example using the RgbLed and RgbColorAlias elements

Here is an example of a front panel configuration file showing usage of <RgbLed> and <RgbColorAlias> elements: 


<?xml version="1.0"?>
<FrontPanelConfig version="2.1">

  <!-- Color aliases for VIP4302 (they will be ignored on VIP43xx) -->
  <RgbColorAlias paneltype="vip4302" name="red-low" color="#200000" />
  <RgbColorAlias paneltype="vip4302" name="red-medium" color="#300000" />
  <RgbColorAlias paneltype="vip4302" name="red-high" color="#FF0000" />
  <RgbColorAlias paneltype="vip4302" name="green-low" color="#002000" />
  <RgbColorAlias paneltype="vip4302" name="green-medium" color="#003000" />
  <RgbColorAlias paneltype="vip4302" name="blue-low" color="#000020" />
  <RgbColorAlias paneltype="vip4302" name="blue-medium" color="#000030" />

  <!-- Color aliases for VIP43xx (they will be ignored on VIP4302) -->
  <RgbColorAlias paneltype="vip43XX" name="red-low" color="#120000" />
  <RgbColorAlias paneltype="vip43XX" name="red-medium" color="#200000" />
  <RgbColorAlias paneltype="vip43XX" name="red-high" color="#FF0000" />
  <RgbColorAlias paneltype="vip43XX" name="green-low" color="#001200" />
  <RgbColorAlias paneltype="vip43XX" name="green-medium" color="#002000" />
  <RgbColorAlias paneltype="vip43XX" name="blue-low" color="#000012" />
  <RgbColorAlias paneltype="vip43XX" name="blue-medium" color="#000020" />

  <!-- State machine for both VIP4302 and VIP43xx (as the last two letters
       for the panel type are ??) -->
  <Panel type="vip43??">
    <Expression value="#PowerProfile,#WiFiState">
      <Result value="active,connected">
        <RgbLed id="1" color1="blue-low" color2="blue-medium"
		transitiontime="1000" holdtime="2000" />
      </Result>
      <Result value="active,connecting">
        <RgbLed id="1" color1="#000000" color2="blue-medium"
		transitiontime="400" holdtime="0" />
      </Result>
      <Result value="active,*">
        <RgbLed id="1" color1="green-low" color2="green-medium"
		transitiontime="1000" holdtime="2000" />
      </Result>
      <Result value="active_standby,*">
        <RgbLed id="1" color1="red-low" color2="red-medium"
		transitiontime="1000" holdtime="2000" />
      </Result>
      <Result value="*">
        <RgbLed id="1" color1="red-high" color2="red-high"
		transitiontime="1000" holdtime="2000" />
      </Result>
    </Expression>
  </Panel>
</FrontPanelConfig>

This configuration will cause the Front Panel Service to act as follows:

  • If the power profile is active and WiFi is connected, RGB LED 1 will start transitioning between the two colors "blue-low" and "blue-medium", where each color will be stable for 2000 ms before transitioning over to the next color, with the transition taking 1000 ms.
  • If the power profile is active and WiFi is connecting (i.e., the WiFi module is trying to establish or re-establish its connection), RGB LED 1 will start transitioning between the two colors "#000000" (no light) and "blue-medium", where each color will be stable for 0 ms before transitioning over to the next color, with the transition taking 400 ms. This color transition should be quite noticeable for an end-user.
  • If the power profile is active and the WiFi is in any other state (e.g. inactive), RGB LED 1 will start transitioning between the two colors "green-low" and "green-medium", where each color will be stable for 2000 ms before transitioning over to the next color, with the transition taking 1000 ms.
  • If the power profile switches to active_standby, RGB LED 1 will start transitioning between the two colors "red-low" and "red-medium", where each color will be stable for 2000 ms before transitioning over to the next color, with the transition taking 1000 ms.
  • If the power profile switches to any other standby mode, RGB LED 1 will be configured to emit the static color "red-high".

The Led and SegmentDisplay elements

The <Led> element is used to specify the behavior of LEDs that have predefined colors.

The attributes available for the <Led> element are as follows:

<Led> element attributes
Attribute name Description
color The color of the LED. See the DTD below for valid colors.
blinkfrequency The blink frequency in Hz. This attribute is optional.
irblinkcolor The color which the LED should blink with when IR input is received. This attribute is optional.

The <SegmentDisplay> element makes is possible to specify a text on a segment display. It has two modes: a text mode where arbitrary text can be shown and a clock mode where the time of day is shown.

The available attributes for the <SegmentDisplay> element are as follows:

<SegmentDisplay> element attributes
Attribute name Description
mode Choose text for showing text and clock for showing a clock.
text The text to be shown. This attribute is only valid if mode is test to text.
colonstate Set to true to show a colon on LED segment display. This attribute is optional.
intensity The intensity of SegmentDisplay in percentage of max intensity.

Example using Led and SegmentDisplay elements

Consider the following example of front panel configuration file showing the usage of the <Led> and <SegmentDisplay> elements: 


<?xml version="1.0"?>
<FrontPanelConfig version="2.1">
  <Panel type="vip19??">
    <Expression value="#PowerProfile">
      <Result value="active">
        <Led label="POWER" color="off"/>
        <Led label="POWER1" color="green" blinkfrequency="0.0"/>
        <SegmentDisplay mode="text" colonstate="false" text="KTV"
			intensity="100"/>
      </Result>
      <Result value="*">
        <Led label="POWER" color="red" blinkfrequency="0.5"/>
        <Led label="POWER1" color="off" />
        <SegmentDisplay mode="clock" colonstate="true" intensity="20"/>
      </Result>
    </Expression>
    <Expression value="$cfg.dlna.dms.enabled,$var.time.valid">
      <Result value="TRUE,TRUE">
        <Led label="GENERIC" color="green"/>
      </Result>
      <Result value="FALSE,*">
        <Led label="GENERIC" color="off"/>
      </Result>
      <Result value="*">
        <Led label="GENERIC" color="red"/>
      </Result>
    </Expression>
  </Panel>
</FrontPanelConfig>

This configuration will cause the Front Panel Service to act as follows:

  • At startup, the Front Panel Service will subscribe to the cfg.dlna.dms.enabled and var.time.valid information objects.
  • If the current power profile is any standby mode, power LED 1 will blink with a red light at 0.5 Hz and power LED 2 will be unlit. The segment display will show a clock and the intensity of the display will be at 20% of the maximum brightness.
  • When the power profile switches to active, power LED 1 will be unlit and power LED 2 will be lit with a solid green light. The segment display will be in text mode displaying the text "KTV".
  • If the cfg.dlna.dms.enabled object is set to TRUE and var.time.valid is set to TRUE, the generic LED will be set to green. If cfg.dlna.dms.enabled is set to FALSE, the LED will be turned off. The LED will be set to red if the objects are set to something else.

DTD specification for front panel configuration files

The DTD below describes the structure of the front panel configuration.

The current version of FrontPanelConfig is "2.1". XML files written since version "2.0" will still be parsed, but it is recommended to update the configuration files to comply with the format described here. 


<!ELEMENT FrontPanelConfig (Panel*)>
<!ATTLIST FrontPanelConfig
	  version CDATA #REQUIRED>
<!ELEMENT Panel (Expression*, RgbColorAlias*)>
<!ATTLIST Panel
          type CDATA #REQUIRED>
<!ELEMENT Expression (Result+)>
<!ATTLIST Expression
	  value CDATA #REQUIRED>
<!ELEMENT Result (Led*, SegmentDisplay?, RgbLed?)>
<!ATTLIST Result
          value CDATA #REQUIRED>
<!ELEMENT Led EMPTY>
<!ATTLIST Led
          id CDATA #IMPLIED
          label CDATA #IMPLIED
          color (off | red | green | orange | blue | yellow | cyan | magenta | white) #REQUIRED
          blinkfrequency CDATA #IMPLIED
          irblinkcolor (off | red | green | orange | blue | yellow | cyan | magenta | white) #IMPLIED>
<!ELEMENT SegmentDisplay EMPTY>
<!ATTLIST SegmentDisplay
          mode (text | clock) #REQUIRED
          text CDATA #IMPLIED
          colonstate (false | true) #IMPLIED
          intensity CDATA #IMPLIED>
<!ELEMENT RgbLed EMPTY>
<!ATTLIST RgbLed
          id CDATA #IMPLIED
          label CDATA #IMPLIED
          color1 CDATA "000000" #REQUIRED
          color2 CDATA "000000" #REQUIRED
          holdtime CDATA #REQUIRED
          transitiontime CDATA #REQUIRED>
<!ELEMENT RgbColorAlias EMPTY>
<!ATTLIST RgbColorAlias
          paneltype CDATA #REQUIRED
          name CDATA #REQUIRED
          color CDATA "000000" #REQUIRED>

5.1.1.p8

Copyright (c) 2018 ARRIS Enterprises, LLC. All Rights Reserved. ARRIS Enterprises, LLC. Confidential Information.