Baruch Even's Blog

Thanks to my co-worker I got the battery shield fully setup, initially I missed the switch and he managed to solder it to a mostly soldered shield and minion. Initial test seemed to indicate that it doesn't work but that was just me wrongly assuming that the led always lights up at startup, loading a blink sketch on the minion proved that the battery shield works just fine.

Note to self: Need to get loading a version across the radio to work, that would be extra cool and make maintenance of the sensor network a breeze. Will need to make sure that I don't brick the minions across the radio.

With the help of a co-worker who soldered for me the minions and the battery shield and also gave me leds and a switch I could get to play a bit with external parts rather than just the internal leds and radio. So far I managed to control a led on/off as well as experimenting with the analogWrite to light it at different levels and also managed to use the switch to turn the led on and off which was really cool.

Next step is to use the leds and the switch on two different minions and to wirelessly transfer the switch status to control a remote led.

To facilitate discussions about the minion I created a mailing list in Google Groups at https://groups.google.com/d/forum/minioncity. Feel free to join.

Yesterday I got the Minion City Arduino compatible device. It's a tiny device that provides Arduino Leonardo compatible board with a built-in RF12B radio. I got two of those to try my hands with Arduino development with the first project planned to be a basic weather sensor (temperature, humidity, barometric pressue, ambient light).

There is scant little documentation, it is all hidden across multiple blog posts and kickstarter project description. The first thing I needed to know was that this is an Arduino Leonardo and then that the LED is on pin 16 rather than the usual pin 13. There is a green led that lights occasionally and I still don't understand it's purpose.

So far I checked the led and the keyboard control which is really nice, now I need to get myself a breadboard and some sensors to do what I really want from it.

After a long hiatus I finally manage to resurrect my blog, switching from pybloxsom to chronicle. Maybe it will mark a renewed period of blogging, maybe not. But at least the old posts will return.

The ingredients for this recipe:

1. A computer with ATI display driver
2. Debian unstable (though testing and etch should work as well)
3. A network connection

Instructions:

1. su -
2. aptitude install fglrx-control fglrx-driver fglrx-driver-dev fglrx-kernel-src modula-assistant linux-headers-2.6-686
3. m-a -t auto-install fglrx
4. aticonfig -f --install
5. Restart X, you can do it with Ctrl-Alt-Backspace, or just restart the computer
6. Enjoy the beautiful new look of your desktop!

If you are using an AMD machine replace the linux-headers-2.6-686 with linux-headers-2.6-k7.

A while ago I bought an MSI laptop, model S420. The sound didn't work but normally I don't really need it anyway so it was never an important issue. A few days ago I started using powertop to understand why my laptop can live on battery for less than two hours. One problem I have with powertop is that I don't get enough information on the C-states of the CPU, they are controlled by the BIOS so I went to the MSI website to hunt for a BIOS upgrade. During the course of this hunt I found an old patch for sound drivers for other models of MSI laptops and in them I found hints for my own sound card. Some guesswork and a single try and I found a patch that makes the sound work me.

I didn't find an explanation or a changelog for the bios upgrades so I didn't try them yet but the patch to get the sound working is following. It is for kernel 2.6.22-rc2 but it should easily be adapted to other kernels, it's just a one-liner. The patch was accepted (in variation) into the ALSA repository and will probably show up in kernel 2.6.23.

--- 2.6-rc2/sound/pci/hda/patch_realtek.c	2007-05-19 13:56:54.000000000 +0300
+++ 2.6.22-rc2/sound/pci/hda/patch_realtek.c	2007-05-25 00:42:42.000000000 +0300
@@ -6389,6 +6389,7 @@
 	SND_PCI_QUIRK(0x1462, 0x4314, "MSI", ALC883_TARGA_DIG),
 	SND_PCI_QUIRK(0x1462, 0x4319, "MSI", ALC883_TARGA_DIG),
 	SND_PCI_QUIRK(0x1462, 0x4324, "MSI", ALC883_TARGA_DIG),
+	SND_PCI_QUIRK(0x1462, 0x3729, "MSI", ALC883_TARGA_DIG),
 	SND_PCI_QUIRK(0x1462, 0xa422, "MSI", ALC883_TARGA_2ch_DIG),
 	SND_PCI_QUIRK(0x1025, 0, "Acer laptop", ALC883_ACER),
 	SND_PCI_QUIRK(0x161f, 0x2054, "Medion laptop", ALC883_MEDION),

KVM is a Kernel-based Virtual Machine for Linux, it has a kernel module that enables a modified Qemu to use the Intel VT extension for full virtualisation, with the benefit of making the virtualisation very fast. In the future it will also support the SVM extension of AMD.

It will be available in Debian once the ftp-masters clear the backlog, and is currently available in a temporary location. The manpage is missing but the instructions to get it to work are:

• sudo apt-get install kvm kvm-source
• sudo m-a build kvm
• sudo m-a install kvm
• sudo modprobe kvm

At this stage you have KVM ready for usage, simply use the kvm program as if it was the Qemu program, to boot a Debian Live CD use: kvm -cdrom live.iso -boot d

In the future the KVM patches will be merged into both the kernel and Qemu and these packages will be gone, but for now, that's the easiest way to use KVM.

Update: KVM entered the archive, instructions above were updated.