I have been away long enough to have pretty much forgotten what my day job is…

As a result of all this hardship, dirt, thirst, and wombats, you would expect Australians to be a dour lot. Instead, they are genial, jolly, cheerful, and always willing to share a kind word with a stranger, unless they are an American. Douglas Adams - English

This little toadstool was taken with a flash each side to light it up, triggered with cactus radio triggers (flashes set to about 1/16th power i think, and quite a small aperture on the macro lens)

I have also been taking some photos of a friends’ band The rivers of sound

Also, following comments on a recent post I decided to get out in the garden and try some photos of the insect life that lives there. Most of these had an off-camera flash on E-TTL auto, though manual actually works better with a little practice (if you get the exposure wrong, the flies are gone before you get a second chance (probably cooked by the power of the flash that close) so E-TTL is easier to start with)

Some are random (as seen below)

I also snapped a close-up of some ants and other insects (aphids?)) eating at the stem of my sunflower. I was quite surprised at the detail I got, though admittedly it was with my ef-s 60mm macro lens

I also got a nice shot of a bee while on a walk one lunchtime at work

And then there is my whole set of photos from Hinton Ampner, which I realised I didn’t have the old ones from last year up, so theres a fair few in there including a whole pile trying to catch a bee flying. (click on the photo below to see the whole set)

And I recently took photos of the Hursley Model Railway (again click on the image below to see the whole set). Some of these were done with an off-camera flash with a coloured gel, which produced some interesting effects, though not very life-like.

Its a shame that they don’t let you hotlink the images like xkcd does

Theres a short articlt on Top Gear

And theres a wonderful video on Youtube

To get the two to play together, you need to turn off live commenting.

In my case, as my blog is also my openid url (see this tutorial in delegating your open id if you want to use your blog or website as your openid url, and any provider), I had to add some code the the k2 style’s functions.php

add_action('wp_head', 'custom_header');

function custom_header () {
        ?>
        <link rel="openid.server" href="...openid provider url..."/>
        <link rel="openid.delegate" href="...openid provider url..."/>
        <?php
}

Now you have your own blog as your openid url, and your blog accepts openid’s for comments with the k2 theme

I have bee following Bert’s blog for a while now, and it really is fantastic - I strongly recommend reading through his archive, particularly for the videos he’s done during shoots.

There is quite a difference in programming between mplab and piklab. Although there is support for a large number of chips in piklab, they are not supported as well as mplab. The big problem is that in mplab most special bits (i.e. each bit for an output port, one per pin) have a defined name so you can set them on or off individually. Piklab on the other hand has support for only a few of these, so if you want to turn on a pin, you have to set a value on the whole port (byte). Saying that, I prefer the piklab editor as it seems to do a better job with syntax highlighting etc.

Below is some code examples to help you get started if you are finding the learning curve steep

Some macros that may be useful to put in a header file are

#define ZERO    0x00  // 0000 0000
#define BIT0    0x01  // 0000 0001
#define BIT1    0x02  // 0000 0010
#define BIT2    0x04  // 0000 0100
#define BIT3    0x08  // 0000 1000
#define BIT4    0x10  // 0001 0000
#define BIT5    0x20  // 0010 0000
#define BIT6    0x40  // 0100 0000
#define BIT7    0x80  // 1000 0000
// macros to manipulate the bits
//set bit Y on byte X
#define SET_BIT(x,y) (x |= y)
//unset bit Y on byte X
#define UNSET_BIT(x,y) (x &= ~y)
//toggle bit Y on byte X
#define TOGGLE_BIT(x,y) (x ^= y)
//test bit Y is set on byte X
#define IS_BIT_SET(x,y)  (x & y)

These can make coding much easier, as then you can just worry about setting the bits and not about conversions to binary.

For anyone not sure how to get anything working, the following code will get you started with the PICKit2 development board and the included 16f690. This is the code to light up different LED’s on the test board depending on what the variable resistor is set to

/* Configuration bits */
typedef unsigned int word;
word at 0x2007 CONFIG = _INTRC_OSC_NOCLKOUT & _WDT_OFF & _PWRTE_OFF
  & _MCLRE_OFF & _CP_OFF & _CPD_OFF & _IESO_OFF & _FCMEN_OFF & _BOD_OFF ;

void main(){
  while(1==1){
  PORTA = 0;//?
  TRISA = BIT0; //Set RA0 input
  ANSEL = BIT0;//  Just RA0 is an Analog Input
  TRISC=0;//Set All PORTC as output

  ADCON0 = BIT0;  //  Turn on the ADC 0000 0001
                  //   Bit 7   - ADFM,Left Justified Sample (0)
                  //   Bit 6   - Use VDD (0)
                  //   Bit 5:2 - Select AN0 channel (0000)
                  //   Bit 1   - GO/DONE - set separately (0)
                  //   Bit 0   - Enable ADC (1)

  ADCON1 = BIT4;//Set AD Control 0001 0000
                // Bit 7   - res
                // Bit 6:4 - Select the Clock as Fosc/8 (001)
                // Bit 3:0 - res

  SET_BIT(ADCON0, BIT1);//GO/DONE to start conversion
  while( IS_BIT_SET( ADCON0,BIT1 ) ){}//Wait until sample is done

  //Set 4 highest bits to write direct to led's. Ignore 4 LSB
  //ADRESH contains bits 9:2 of result
  PORTC = ADRESH >> 4;
  /*
    //Could also make ACDValue only contain upper 4 bytes
    ADCValue >>= 4;
    ADCValue &= (BIT0 | BIT1 | BIT2 | BIT3); // could also do this with 0xF0 (i think)
    //And then set only those bytes
    PORTC |= ADCValue
    //This would mean other bits of portC would still be same
  */
}
}

The datasheets for the pics can be hard to get started with, so hopefully that helps a bit. The examples I saw for doing similar things were ridiculously complicated and without good reason. Of course this code is specific to the 16f690, but it should be easy enough to convert.

Of course I found out the hard way that Amarok didn’t have support for my iPod, and nearly bricked the thing. Thankfully a windows box and iTunes could reset it.

I now have it working, however it took a little fiddling. If you are trying to get it working, you absolutely must read http://amarok.kde.org/wiki/Media_Device:IPod before starting, especially #My_iPod_does_not_show_any_music, as this explains how to set up the magic ID number. Unfortunately earlier pages didn’t say whether to add the 0x in from of the ID, and I remember having lots of difficulty just with libgpod and gtkpod. While I am mentioning it, the versions you need for an iPod Classic are: Amarok 1.4.8 and libgpod 0.6.0

So you have them installed, and you want to get Amarok managing your iPod - Well, I plugged it in, amarok detected it popped up a window asking if it should mount it as an iPod. I said yes, copied some songs, ejected it and BANG! - My iPod wouldnt show any songs.

It seems that the data uploaded by iTunes isn’t the same as by Amarok, and the iPod doesnt like that. Deleting the contents of the iPod_Control folder from the iPod seemed to make Amarok and the iPod happy. Of course Amarok needed to recreate some folder structure, but it asked nicely. Also, if you do this, don’t forget you have to recreate your SysInfo file again before Amarok uploads any songs.

Anyway, I now have an iPod that I can upload to with Linux (which is a hell of a lot faster than iTunes - iTunes took about 30 hours to copy ~30G of music, Amarok took about 3 hours), podcasts work and even some cover art has been copied.

If you have any problems, you can reboot the iPod by holding the Menu and select button down together for a few seconds. If the songs list comes up blank, then you have something wrong and Amarok didnt write the hash correctlty - check the SysInfo file, delete all music from the iPod in Amarok, and copy a few test tracks, disconnect and check if you have it right.

You can also use the Smart Playlists to sync to the iPod - Favourite tracks, Newest tracks and All Collection are good ones to use. Of course you can create your own custom smart playlists too.

Best of all, Amarok is properly multi-threaded so I can copy my entire music collection to my iPod, while playing music and Amarok and writing blog posts - on windows syncing an iPod used to make the system struggle, and iTunes became rather unresponsive…

Unsurprisingly, I took a camera - This is what happened

The rest of the photos are in the set Mottisfont Abbey on flickr

I have a fileserver box, which currently has 2×200GB disks in lvm to give me a 400GB virtual disk. This arrangement gets good use of space, but if one disk has a failure, then the whole filesystem is trashed and cannot be recovered.

The solution is to start using raid. Before I go on, raid is not a backup solution. It cannot protect you from accidentally deleting all your files, and will not protect you from a virus or malicious user or hacker. Raid just reduces the damage if a disk happens to fail (which knowing my luck, is sometime soon).

The final solution I want is 2×500GB disks in raid1 (mirrored) with lvm on top to split into my partitions. This way I could add another pair of disks in raid, add them to the lvm and not have to worry about which partitions get new space, as lvm will allow me to expand any parition onto the new space, and have a partition across multiple disks.

Why not raid5? Raid 5 is great for getting space, as you have n+1 disks, and get the space of n disks out of it as one is the redundant disk. The problem with raid5 is it is limited to the smallest disk in the raid. So 2 500GB disks and one 200GB disk will only give 400GB as each disk can only be used up to 200GB. Raid5 is great if all your disks are the same size, but if I want to add disks, and not have to replace all 3+ disks, then with raid1 I just have to buy disks in pairs. My pc has 4 ide slots and 2 sata slots, so raid1 should be fine (disks are getting quite bit these days).

So the plan is to add 2 500GB disks. put them in raid1 with a partition for /boot (which cant be in lvm) and the rest becomes part of a lvm group, with my / and /home partitions in there (and /tmp, swap)

How I did it

Warning: This can seriously mess up your data. Please, please backup first - I didn’t and was sweating hard at one point when I thought I had lost my entire lvm array. I found the Debian From Scratch (DFS) a fabulous rescue CD

Note: This took me several attempts to actually finish writing, so there are probably some errors, so let me know if you spot anything that looks wrong or is ambiguous.

For background, my current setup has 2 disks. hda and sda. these are both 200GB, and /boot and swap are on hda, and the rest of hda and all of sdb are in my lvm group

I added my new 500GB disk as /dev/sdb and booted up.

Use fdisk to create a small (~100mb) parition for /boot. Set its type to fd (linux raid). This parition cannot be in lvm, as grub does not understand lvm.
Create another parition using the rest of the space for our lvm. Also set its type to fd

You may need to use partprobe or reboot to see the new partitions, however my Debian Etch box autodetected them when leaving fdisk

Installing raid

$apt-get install mdadm
$cat /proc/mdstat should look something like

Personalities : [linear] [multipath] [raid0] [raid1] [raid6] [raid5] [raid4] [raid10]
unused devices: <none>

if not, you may need to load some modules “modprobe md;modprobe raid1″

Next, you will need to create some raid device entries.

$mknod /dev/md0 b 9 0
$mknod /dev/md1 b 9 1

This creates a block device, major number (like a type) 9. As etch uses udev, you need to tell udev to do this next boot too

$echo M md0 b 9 0 >> /etc/udev/links.conf
$echo M md1 b 9 1 >> /etc/udev/links.conf

Now we can create our real raid array:

$mdadm –create /dev/md0 –verbose –level=1 –raid-disks=2 /dev/sdb1 missing
$mdadm –create /dev/md1–verbose –level=1 –raid-disks=2 /dev/sdb2 missing

or the short version

$mdadm -C /dev/md0 -n 2 -l 1 /dev/sdb1 missing
$mdadm -C /dev/md1 -n 2 -l 1 /dev/sdb2 missing

This creates a raid1 array md0 which has parition sdb1 in it and is expecting another disk soon, similarly raid1 array md1 has partition sdb2 and also expects another disk. A raid array without all its disks is called a degraded array, as it is running and works, but is not in good condition.

Next we need to save the state of this array so that it will be loaded at next boot

$mdadm –detail –scan >> /etc/mdadm/mdadm.conf

Adding/modifying VM

To create a new lvm setup, the following commands are a quick guide to creating a single partition in your raid. You will probably want to create a few more paritions, as this just creates a single lvm logical volume called root

$pvcreate /dev/md1
$vgcreate vg0 /dev/md1
$vgscan
$lvcreate -L10G -n root vg0
$mkfs -t ext3 /dev/vg0/root

Then edit /etc/fstab to mount /dev/vg0/root (you may need to refer to it as /dev/mapper/vg0-root) as /. Repeat for any other filesystems you may want, and then copy any data over

e.g.

$mkdir /mnt/root
$mount /dev/vg0/root /mnt/root
$rsync -auHxv –exclude=/proc/* –exclude=/sys/* –exclude=/boot/* –exclude=/mnt / /mnt/root/
$mkdir /mntroot/proc /mntroot/boot /mntroot/sys
$chmod 555 /mntroot/proc

I already had a LVM setup, so I wanted to migrate it from the old disks to the new raid disks

$pvcreate /dev/md1
$vgextend vg0 dev/md1
$pvmove /dev/hda3 (this is gonna be slow)
$vgreduce vg0 /dev/hda3
$pvremove /dev/hda3

Don’t forget a swap partition (can be in LVM too)

$lvcreate -L2G -n swap vg0
$mkswap /dev/vg0/swap

Make sure you copy over your /boot to /dev/md0 too!

Then make sure you have edited /boot/grub/devices.map and /boot/grub/menu.lst to have the correct new devices

Finishing off the config

rebuild initrd to scan for raid devices
!important, you need this for your initrd to load the raid so your kernel can find the root fs!

$dpkg-reconfigure linux-image-2.6.18-3-686

(or whatever your current kernel package is). This is better than mkinitrd or update-initramfs as you dont need to worry about which you are using and is the “debian way”

Someone suggested adding a fallback in grub and a second boot entry, but they don’t use the automagic grub updating, so it will just get trashed when they upgrade kernels
edit /boot/grub/menu.lst if you want to do this

[...]
default 0
fallback 1
[...]

install grub on new disk(s)

you can reboot now if you want to see it working

Add second disk to raid

create same partition structure on /dev/sda, then add them to the raid as follows

$mdadm –detail –scan
$mdadm /dev/md1 -a /dev/sda2
$mdadm /dev/md0 -a /dev/sda1

$watch cat /proc/mdstat
Personalities : [raid1]
md0 : active raid1 sda1[2] sdb1[0]
104320 blocks [2/1] [U_]
resync=DELAYED

md1 : active raid1 sda2[2] sdb2[0]
488279488 blocks [2/1] [U_]
[>....................] recovery = 0.1% (779328/488279488) finish=93.8min speed=86592K/sec

unused devices: <none>

when done you should see:

$cat /proc/mdstat
Personalities : [raid1]
md0 : active raid1 sda1[1] sdb1[0]
104320 blocks [2/2] [UU]

md1 : active raid1 sda2[1] sdb2[0]
488279488 blocks [2/2] [UU]

unused devices: <none>

delete the array lines from /etc/mdadm/mdadm.conf and run

$mdadm –detail –scan >> /etc/mdadm/mdadm.conf

I am surprised that raid cannot figure this information out itself, but every webpages I saw says you need these lines in the config, and I am too scared to try not having those lines.

Make sure you rebuild your initrd so that it knows the raid setup at boot time and can initialise your root partition.

$dpkg-reconfigure linux-image-2.6.18-3-686

Add grub to second disk if desired

$install-grub /dev/sda

discussion

some sites suggest that dmadm.conf needs “devices=/dev/sdb6,/dev/sda6″ for each array. Not sure if this is necessary. If you think you need it, other sites also suggest to use /dev/.static/dev/sdb6 instead of just /dev/sdb6 to make udev work properly. I dont have any devices set for my arrays - I would assume that is what the uuid is for, and mdadm finds them by scanning all paritions

I found the following page really helpful - http://xtronics.com/reference/SATA-RAID-debian-for-2.6.html

It is an absolute must read if you use Gmail

A map of the woods which was quite helpful is available from the forrestry commission

This is something I plan to do every year

There are plenty of sites giving all the technical details of the new Canon 40D, personally I like dpreview.com, so I will not spend too long going over them and instead want to write about my experience using the 40D (especially as an upgrade to my aged 300D).

The first thing to notice about the 40D when you get it out of the box, is the size of the screen. It is truly enormous compared to the 300D - the same difference as moving from a portable TV to a large plasma. It is a very nice screen too, very useful for reviewing photos, especially with the new full RGB histograms. The only gripe with it is that with auto rotate set (which I want on so that the photos are rotated on my pc) all portrait format photos are fitted onto the screen rotated, so you lose half the space on the screen.

The live mode makes good use of this large screen, however when compared to a compact digital camera or even the Panasonic Lumix DMC L10 it is a very primitive live mode. Turning on live mode requires a setting a custom option buried deep within the camera menu. Then you have live mode turned on or off when you press the right button, but it has no focusing - it is all manual! You can use the autofocus by switching off live mode and focusing, or using the focus button, however this flips the mirror back up, disabling the live mode, while focusing. This all means that the live mode is no good for shooting from the hip or above the head without some preparation, as you cannot see what the camera decided was in focus on the screen.
The live mode however is very useful for macro photography, or any time you want to use manual focus on a tripod. You can zoom in 10x on the screen and get a high-res view of a section of the screen. The section can be moved with the joystick to select the area you wish to zoom in on.

Speaking of the joystick, the camera has 3 input selectors - the joystick, which is 8 way plus push, the thumb scroll wheel, which can be enabled with the second on setting of the power button, and the normal scroll wheel next to the shutter button. The two scroll wheels are used for setting the iso, flash adjustment, drive mode, focusing mode, white balance and metering mode. These settings come in pairs, pressing the set button for that pair enables each scoll wheel to adjust each of the settings, which works very nicely in practice once you have learnt which controls which.

The joystick however is normally only enabled for scrolling around a zoomed in image, or for selecting the focus point after pressing the focus point selection button. There is an custom setting though that allows the joystick to be used to select a focus point without pressing the selector button first, with the selector button used to set it back to auto. Personally I find the joystick perfect for selecting a focus point, as the 8 way plus center arrangement lines up nicely with the diamond layout of the focus points. The same custom option also allows to set the thumb scroll wheel to select the focus point however this means that to adjust the exposure you have to hold the focus point selection button and use the finger scroll wheel, which I find annoying compared to just using the thumb scroll wheel.

The high speed burst mode, 6 fps, and low noise of the camera is obviously far superiour than the 300D, and the larger buffer is quite a change from the 300D. 16 RAW images, or around 60 high quality jpgs without having to pause is great for action shots. The write to card speed is also hugely improved from the 300D, meaning I don’t have to worry about filling up the buffer.

The focus points are more sensetive, though with only my macro lens being f2.8 as needed I have not noticed the difference. The center focus point is super sensitive, though I don’t have any lenses with a large enough aperture to take advantage of this.

The af button is still something I have yet to figure out how to use to my advantage, other than starting auto focus during live mode. There are a lot of options for it in the custom functions, but they are somewhat cryptic, and I am used to not having it. Other custom options include controlling what the manual focus switch on the lens does - you can set it to control extra options on focusing or use it to disable lens stabilising, though most IS lenses have a switch for that too

The one new feature which can be realy useful, is on the main control dial there are now 3 custom modes. Each can be set to use P, Av, Tv or M and all other settings, including custom functions such as mirror lockup can be set. I find this really useful for macro shots, where I set one of the custom modes to M with shutter lockup and the two second timer. This allows me to set all the custom settings at once, and revert back to normal shooting with ease. There are also options like long exposure noise reduction and high sensitivity noise reduction which I have yet to really use as they increase the processing time of photos and often I want to see the photo and get on with the next shot.

The mirror lockup, two second timer, and two choices of drive speed (3 and 6 fps) are all new compared to the 300D, though not new to the Canon range of cameras.

The picture styles mode sounds great, especially being able to shoot black and white photos directly from the camera (something my old Canon G2 used to be able to do), however the settings are not picked up on a RAW file by my software (Bibble) so I rarely use it. Black and white is also better when done in post processing as you have many more options, such as selecting the colour channels to use, which is equivalent to using a coloured filter with black and white mode (or black and white film in a film camera).

Overall it is a fantastic camera, though that should not be surprising. Compared to the 300D it feels very professional, and the extra weight just makes it feel more sturdy in your hands and easier to keep steady. The full control of focusing modes and metering is great and means I don’t have to remember which modes are tied to which camera mode as was the case in the 300D where only the sports shooting mode gave you continuous AI servo focus. If you want to use the Live Mode for anything more than accurate macro focusing, I suggest you look elsewhere though

For me, a 400D was too little an upgrade for the money, wheres the 40D really feels like it is worth the upgrade.

It is worth noting that the exploit affects any keys that were built on a debian box after sarge (so etch, lenny, current sid). This also means that any box that has those keys as an authentication method is vulnerable too:

http://blog.drinsama.de/erich/en/linux/2008051401-consequences-of-sslssh-weakness.html

Because any of those boxes could already be compromised, if you are paranoid you should be careful about logging in with passwords to them too - basically if you are paranoid then you can’t really trust anything (so business as normal for paranoid people)

In order to fix your keys, you should probably do the following (thanks to Hugo Mills)

on all boxes you own

• Install the patch
• Delete the following files if the host keys are likely to be vulnerable:
  • /etc/ssh/ssh_host_dsa_key*
  • /etc/ssh/ssh_host_rsa_key*
• Generate new host keys:
  • sudo dpkg-reconfigure -plow openssh-server
• Restart the ssh daemon

And on all boxes you have access to via keys

• Delete the following files:
  • ~/.ssh/authorized_keys
  • ~/.ssh/id_*
• Generate new personal keys:
  • ssh-keygen -t rsa -b 4096