Monthly Archive for May, 2008

PIC Microchip programming under debian

A while ago I bought a PICkit2 programmer, including 16f690 PIC. I installed piklab and sdcc (in Debian repositories) and got it working pretty easily. I did play with the programmer that came with it (mplab, windows only), which upgraded my firmware. piklab cannot use the new firmware, so if you need to get an old firmware, then try the old firmware downloads page

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

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iPod Classic with Amarok on Linux

When I first bought my iPod classic, Amarok hadn’t yet got support for the new SHA1 hashing that was being done in the song db. Then it was only in cvs, and while I remember compiling from source I don’t think I ever got round to running that code.

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…

Mottisfont Abbey

A few weeks ago, when the weather was excellent, I went to Mottisfont Abbey trying to make the most of my National Trust membership. In case you want to go, the following point on the map is a little more accurate than on the national trust page (the rough coordinates from my gps module)

Unsurprisingly, I took a camera – This is what happened

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

software raid1 and lvm on debian etch

Background

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

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Get more out of Gmail

I stumbled across this post on the Official Gmail Blog: 2 hidden ways to get more from your Gmail address

It is an absolute must read if you use Gmail

Random Photos

I stumbled over these photos the other day, and decided I really liked them.
I couldn’t remember if I had posted them up here, so decided to post them anyway

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