Static sound in Ubuntu

I just updated to the 2.6.28-13 kernel in Ubuntu 9.04 and sound was just playing static. The solution was to raise the volume on the PCM slider, for some reason it was down to 0.

How to Enable Digital Microphone Array on Dell Inspiron Laptops in Ubuntu 8.04

Some of the new Dell Inspiron laptops (the 1420n, 1520, and 1525 are the ones I know of) come with a digital microphone array above the screen, but a fresh install of Ubuntu 8.04 will not have the array enabled by default.

Fortunately, it wasn’t too difficult to enable, and now I can use Audacity, Skype, etc., without any peripherals.

Although Hardy’s usage of the new Pulseaudio system is causing problems with many audio applications, the problem in this case seemed to be alsa-based

1. Right-click the volume applet in the top-right of your screen and click Open Volume Control.
2. Click File > Change Device and change the device to the alsa device.
3. Now click Edit > Preferences and select both Digital and Digital Input Source.
4. In the Recording tab, make sure the digital device’s volume is all the way up and that the device is not muted.
5. In the Options tab, change Digital Input Source: to Digital Mic 1.

Fun with Google Trends

Google Trends got some updates so I was playing with it. Some funny correlations:
New Years Resolutions
The changing seasons

Enable indicator LED for Intel 2200BG and 2915ABG wireless cards

The 2200BG and 2915ABG cards use the ipw2200 driver, which is able to control the wifi indicator LED which most laptops will use.

To enable, run the following as root or with sudo privileges:
echo "options ipw2200 led=1" >> /etc/modprobe.d/ipw2200.modprobe
modprobe -r ipw2200 ; modprobe ipw2200
Note that these steps were used with a Dell Inspiron 6000 and Ubuntu 7.10. Certain chipsets may instead use the acerhk module, or need to add the “options ipw2200 led=1″ to a different location.

Best, xrandr 1.2 hotplugging goodness.

To get my dual-screen setup working, I first used Xinerama, which worked, but had a (blocker, for me) bug that would distort the cursor.

I then tried MergedFB using the Radeon driver, and it was good. I could play games with the 3D accelerated screen, and the mouse was quite usable.

In the latest xserver release (1.3) MergedFB functionality has been deprecated by the robust RandR 1.2 (X-Windows Resize and Rotate). With this release, the X Server supports hotplugging, meaning a monitor will be automatically detected when plugging it in, and can be enabled without restarting the X session.

When I tried this, xrandr set up both monitors at their native resolutions, 1280×800 and 1680×1050, but mirrored the display instead of extending it. How did it mirror by using different resolutions, you ask? it overlayed the 1280×800 screen in the top-left corner of the 1680×1050 display. Funny, but not what I wanted

The solution ended up being to disable the S-video out port on the video card explicitly, using xrandr --output S-video --off and then xrandr --output VGA-0 --right-of LVDS to extend the desktop onto the second monitor instead of mirror it.

It was also necessary to increase the size of the Virtual screen. So the only xorg.conf modification I made ended up being this:
Section "Screen"
...
SubSection "Display"
Virtual 2960 1050
EndSubsection
EndSection
Of course, other resolutions will vary in their required Virtual screen size.

A good reference is Intel’s xrandr 1.2 dual-head page here. Although it deals with the Intel graphics driver, the basic idea is the same for the radeon drivers.

Better, Dual-Head using MergedFB and Radeon driver

update: The radeon driver no longer uses mergedfb, but randr for multiscreening.

Xinerama was quite a suboptimal solution for my setup. What advantages does MergedFB provide?

1. 3-D Accelerated Dual Screens
2. Ability to use HW Cursor
3. Allows dual monitor setup without using proprietary fglrx driver
4. easy setup

My setup:

I’m running an ATI Mobility Radeon X300, with my primary monitor (laptop screen) at 1280×800 and my secondary monitor (Samsung Syncmaster 206BW) at 1680×800 (on the VGA port unfortunately, it’s all the laptop has)

Dual Head video using Xinerama and fglrx

If you are trying to add a second monitor to your laptop running an ATI video card, the following should help you.