The LCDuino-1 display I/O processor

User guide

LCDuino-1 is easy and intuitive to use. This section is a general operating manual for the LCDuino-1 running unmodified Volu-Master or γ3 firmware. The following is a summary of the topics covered:
  1. Remote control quick reference
  2. Front panel controls
  3. Detailed function descriptions
  4. System reset

1. Remote control quick reference

All features of the LCDuino-1 are accessible via the wireless remote control. LCDuino-1 must be adapted to your remote control with "Learn IR". See the Setup section for details.

The following is a table of learned remote control keys and their functions during normal operating mode. In Menu setup mode, some the keys are unused while others are used for navigating the menu system.

KeyDescription
Up Arrow Increase volume (coarse)
Down Arrow Decrease volume (coarse)
Right Arrow Increase volume (fine)
Left Arrow Decrease volume (fine)
Mute Mute/un-mute audio
Up Alias Increase volume (fine)
Down Alias Decrease volume (fine)
Power Turn power on/off
Menu Enter/exit Menu setup mode
Sleep Enable/disable sleep timer (Volu-Master only)
Anti-clip Enable/disable anti-clip mode (γ3 only)
Backlight Toggle between three display backlight modes
Display Toggle between different main screens
1..8 (numeric key) Select input or output port(s) (Volu-Master only)
0..4 (numeric key) Select digital input (γ3 only)
Multi-out Enable/disable multi-output mode (Volu-Master only)
Filter Select filter (γ3 only)

2. Front panel controls

LCDuino-1 supports a front-panel mounted pushbutton switch and an optional potentiometer. Further, the potentiometer may be a motorized unit.

Pushbutton:

  • As power on/off switch: When the power is on, press and hold for a few seconds to turn off. When power is off, press briefly to turn on.
  • As mute/un-mute switch: When power is on, a brief press mutes the audio. Press again to un-mute.
  • At power-on, the switch could be used to trigger Basic initialization mode, which let's you restore all configuration data to factory defaults, perform the "Learn IR" sequence, or skip keys while in Learn IR.

Potentiometer (if equipped):

  • As volume control: Turn clockwise to increase volume, turn counter-clockwise to decrease. If you use the remote control to change the volume, and your potentiometer is motorized, LCDuino-1 will activate the motor and synchronize the knob position to the current volume.
  • Since LCDuino-1 remembers the volume level on a per-input basis, if you change the input, the volume will be restored to the previous level on that port, and the potentiometer motor will be activated to move to the restored level.
  • In Menu setup mode, the potentiometer is used as an alternative to the remote control for selecting field entries. If the potentiometer is motorized, when exiting Menu setup mode, LCDuino-1 will activate the motor and re-synchronize the knob position to the current volume.

3. Detailed function descriptions

The following sections describe the functions you could perform while LCDuino-1 is in normal mode (i.e., it is displaying the Main screen).

Power on/off

Since LCDuino-1 is always powered, "Power on/off" here refers to LCDuino-1's control of power to the rest of system being managed, which is usually the analog amplifier circuitry. See the Wiring section for details.

Power on

Turn on the power by briefly pressing the Power key on your remote control, or the front panel CFG/PWR pushbutton.

With Volu-Master, after the power is on, the display shows a countdown of the muting delay feature. During this time, all of δ2's output ports are disabled to prevent any turn-on noise. The delay interval is adjustable via Menu setup. If it was configured to be 0 seconds, then this screen is skipped and all outputs ports are enabled immediately.

Volu-Master

After the muting delay interval, if the power was turned on using the CFG/PWR pushbutton, then the start-up banners appear briefly. These banners can be customized through Menu setup. The following shows the default banner text. The banners are not displayed if the power is turned on using the remote control for faster start-up.

Volu-Master     γ3
   

The LCDuino-1 then displays the Main screen and enters normal operating status.

Power off

Briefly press the Power key on the remote control. When using the front panel CFG/PWR pushbutton to turn off the power, you must press the the button and hold it down for a few seconds.

With Volu-Master, LCDuino-1 disables all δ2's output ports before killing the power, to prevent any turn-off noise. After the power is off, the display shows the first banner and the clock (or the second banner if your LCDuino-1 is not configured with a clock). With γ3, after the power if off, the display shows both the first and second banners.

Volu-Master     γ3
   

The display will either be on, auto-dimmed, or completely dark depending on your Backlight control setting.

Main screen

The main screen is what you see on the display when LCDuino-1 is in the normal operating mode. With the exception of the "large font" screen, all other screens are divided into four quadrants, each of them up to eight characters long. Each quadrant shows screen-specific operating information.



With Volu-Master, there are four versions of the main screen that you could cycle through by pressing the Display key of your remote control. Note that the Volu-Master screen examples shown below have user-defined input/output port names ("gamma2" and "beta24", referring to the AMB γ2 DAC and β24 power amplifier, respectively). With γ3, there are three main screens.

The current main screen is remembered across a power off/on cycle.

Volu-Master     γ3
A     A
   
B     B
   
C     C
   
D      
     

Main screen "A"
This version shows the input selector port name in the upper left quadrant, a volume control bargraph in the lower left quadrant, and a volume control dB readout in the lower right quadrant. If Mute is on, then the bargraph area shows "MUTE".

With Volu-Master, the upper right quadrant shows the output selector port name. If Multi-Out mode is enabled, then the output port name area shows the port status rather than the name. If your LCDuino-1 is not configured with a volume control engine, then the bargraph and dB readout are not displayed.

With γ3, the upper right quadrant shows the current digital input sample rate. If the DAC cannot lock on to a valid sample rate, then this quadrant will show a blank.

Main screen "B"
This screen shows the volume dB attenuation in a large font face for easy viewing from a distance. If Mute is on, then the display shows hyphen characters ("") instead of the dB value.

With Volu-Master, if the Sleep timer is on, then a small clock icon appears on the right side of the display. This screen is not available if your LCDuino-1 is not configured with a volume control engine.

Main screen "C"
With Volu-Master, this screen is similar to main screen "A", except the lower left quadrant shows the sleep timer countdown ("Snn", where nn is the number of minutes remaining to shutdown). If sleep mode is not active, then "S--" is shown. The descriptions for Main screen A regarding Multi-Out and Mute modes also apply to the lower left and upper right quadrants.

With γ3, the lower left quadrant shows the selected filter response number (there are five to choose from). The upper right quadrant shows "AntiClip" if the anti-clip mode is enabled, otherwise it's blank. The descriptions for Main screen A regarding Mute mode also apply to the lower left quadrant.

Main screen "D"
Same as main screen "A", except the lower left quadrant shows the clock (current time in 24-hour format). The descriptions for Main screen A regarding Multi-Out and Mute modes also apply here. This screen is not available if your LCDuino-1 is not configured with a clock.

The following are more screen examples. This screen below shows main screens "A", "C" or "D" while Mute is on:

Volu-Master     γ3
   

This is main screen "B" while Mute is on:

Volu-Master and γ3

This is main screen "B" while the Sleep timer is on:

Volu-Master

Backlight control

You could choose from three display backlighting modes by pressing the Backlight key on your remote control.

Backlight On
The display is always "bright".
Backlight Auto
The display is "bright" when there is user activity, but goes to a "dim" state after a few seconds.
Backlight Off
The display is "bright" when there is user activity, but goes completely dark after a few seconds.

"User-activity" refers to pressing a remote control key, turning the volume knob, etc. The bright and dim levels are user-adjustable via Menu setup.

When you change the backlight mode, a screen message appears momentarily to show the new mode:

       

Then, the display reverts to the Main screen. The following shows examples of the main screen in bright, dimmed and off states:

       

The selected backlight mode also applies when the LCDuino-1 is in the powered-off state.

Changing the volume

You can change the volume using your remote control or, if equipped, the front-panel potentiometer. You can also mute and un-mute the audio using the remote control, or the front panel PWR/CFG pushbutton. These controls act on both stereo channels of all installed δ1 boards simultaneously.

With the remote control, you have the choice of fine and coarse volume adjustments:

Fine adjustment - Right Arrow, Left Arrow, Up Alias and Down Alias keys
Each key-press increases or decreases the volume by one "native" step (according to your δ1 board's resistor values). This is configured in Menu setup.
Coarse adjustment - Up Arrow and Down Arrow keys
Each key-press increases or decreases the volume by a user-specified step size. It allows you to make large volume changes quickly. See Menu setup

With the front panel potentiometer, turn clockwise to increase the volume or counterclockwise to decrease.

In all cases, the volume adjustment range (minimum and maximum limits) is also user-configurable, via Menu setup. These limits are applied to the total rotational sweep of the potentiometer. For example, if you set the minimum and maximum limits to -40.0dB and -10.0dB, respectively, then these will become the potentiometer's fully-counterclockwise and fully-clockwise positions.

The Mute feature allows you to silence the audio temporarily. To activate, simply press the Mute key on your remote control or the front panel PWR/CFG pushbutton. To un-mute, just press the Mute remote key or PWR/CFG pushbutton again. Increasing the volume will also cause an un-mute, but decreasing the volume will not. This lets you change to a lower volume setting while muted, and then un-mute to the new setting.

Mute applies to all inputs -- if you enable mute while on one input, it will remain muted if you change to a different input. With Volu-Master, the muted level is not necessarily total-silence -- it is also governed by the minimum volume limit described above.

The current volume level and mute status (if enabled) are displayed on the Main screen. The following shows the main screen in bargraph mode, at minimum and maximum volume settings (with Volu-Master, for an 8-relay, 0.5dB/step configuration):

Volu-Master     γ3
   
 
   

If the potentiometer motor is running, you should wait for it to stop before using the potentiometer to change the volume. You can use the remote control to override the motor at any time.

If the motor is running while you enter Menu Setup, the motor will stop. When you exit Menu Setup, the motor will be activated to restore the volume position if necessary.

Selecting input and output(s) (Volu-Master only)

The 1 to 8 keys of your remote control's numeric keypad are used for selecting the δ2 input and output ports. The key number correspond to the port number on the δ2 board plus one, because the board's port numbers are 0 to 7.

Only one input port may be selected at a time. Selecting a new input port will de-select the previous input port. The selected input port name (user-customizable) is displayed on the Main screen.

For output ports, there are two modes, Single-Out or Multi-Out. You choose between the two modes by pressing the Multi-Out key on your remote control.

Single-Out
Only one output port may be selected at a time. Selecting a new output port will de-select the previous output port. The selected output port name (user-customizable) is displayed on the Main screen.

The example main screen below is in Single-Out mode. The input port named "gamma2" and the output port named "beta24" are selected.



Multi-Out
Multiple output ports may be selected simultaneously. The remote control's numeric keys become toggles on each output port - press to enable, press again to disable. The output port name area on the Main screen changes to show the status of each port. The eight character positions, from left to right, corresponds to the port numbers 1 through 8. An "I" character indicates that the port is the selected input port. A hyphen ("") character means that the port is de-selected, and digit characters ("1" to "8") show all enabled output ports. Note that in this mode it is possible to disable or enable all output ports.

The example main screen below shows Multi-Out mode, where the input port named "gamma2" is selected, and output ports 5 and 8 are enabled. We could also see that "gamma2" is port 1.


Notes:
•  Each δ2 port can be set up as an input or output port via jumpers. See the δ2 website. The port configuration should then be configured via Menu setup.
•  Each "port" mentioned here is actually two physical ports (the left and right channels) on each δ2 board. These controls act on both stereo channels of all installed δ1 boards simultaneously.
•  LCDuino-1 remembers the volume setting on a per-input port basis. When you change input ports, the volume will be restored to the previous level on that port.
•  LCDuino-1 remembers the selected output port in Single-Out mode. When you change from Multi-Out mode back to Single-Out, the saved port will be restored.

Screen Messages

When the display is in Main screen C ("big font") mode, if you change input or output ports, the screen momentarily displays the original port and the new port we've switched to, then the display reverts to the main screen. Here is an example of the screen message when you switch the input port from "gamma2" to the port "gamma1":



Here is an example of the screen message when you switch the output port from "beta24" to "beta22" while we're in Single-Out mode.



This is a screen message example in Multi-Port mode, where output port 5 was already enabled but we've also enabled output port 6:

Selecting input (γ3 only)

The 0 to 4 keys of your remote control's numeric keypad are used for selecting the γ3 digital input. Key 0 correspond to the USB input, while keys 1 to 4 refer to the four AES/EBU or S/PDIF inputs.

Only one input may be selected at a time. Selecting a new input will de-select the previous input. The selected input name (user-customizable) is displayed on the Main screen.

Sleep timer (Volu-Master only)

The sleep timer feature, when activated, will cause the power to be turned off automatically after a user-defined amount of time. To activate the sleep timer, press the Sleep key on your remote control. Pressing the key a second time will deactivate it. The amount of time (in minutes) to auto-shutoff can be set via Menu setup.

When you activate or deactivate the sleep timer, a screen message appears momentarily:

   

Then the display reverts to the Main screen. When the sleep timer is activated, the main screen may either show a time countdown or a clock icon (depending on the main screen mode selected).

If you manually turn off the power while the sleep timer is still active, it will be deactivated when you turn the power on again.

Anti-clip mode (γ3 only)

The Anti-clip key on your remote control can be used to enable or disable anti-clip mode. When enabled, a 2dB digital attenuation is internally applied in the DAC.

The new mode is displayed on the screen as you are making the change, as well as on Main screen C.

Selecting the filter response (γ3 only)

The Filter key on your remote control can be used to toggle amongst five digital anti-alias filter responses, as follows:

  1. Linear Phase "soft knee" filter
  2. Minimum Phase "soft knee" filter
  3. Linear Phase "brick wall" filter
  4. Minimum Phase Apodizing filter
  5. Linear Phase Apodizing filter

The new filter response is displayed on the screen as you are making the change, as well as on Main screen C.

Menu setup

LCDuino-1 has a number of user-defined settings and options. These are done through Menu Setup. See the Setup section for details.

4. System reset

You can reset the LCDuino-1 using one of two methods. In the unlikely event that the Atmel MCU encounters a glitch or hang, this will reboot it. Resetting in this manner does not erase your custom configuration settings.

  • Press the "Reset" pushbutton located on the LCDuino-1 board.
  • Unplug the power cord from the AC wall outlet, wait a few seconds, and then re-plug it. This interrupts the "constantly-on" 5V DC powering the LCDuino-1 board and forces a reboot.

Note that neither method would erase the EEPROM data, which contains your configuration/setup information and saved states.


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