I am making some progress toward a manufacturable design of my RS232 baud rate converter. I now have the prototype working.

As you can see from the photo, I had to add a couple of wires to the PCB but only a couple and I am very pleased about that!

I am going to revise the board design before sending it for manufacture - apart from the couple of patches I also forgot to bring out the chip programming lines and the reset line. These are not needed for normal operation but will be needed to initially program the chip. To this end I am putting a new 10-way header on the board for programming and debugging.

Another issue I had when bringing the thing from prototype to a production stage was the firmware. I realized there really should be some way for end users to update the firmware either to patch bugs or add new features when customers inevitably request them. I do not want to be physically mailing these things back and forth for modification once they are sold. To that end, I have written a boot loader and firmware update utility.

I’m now ready to get the board manufactured. I want to do a small run of 20 or so to start off with. I used BatchPCB for my prototype but they are not cost-effective for more than one or two boards. After comparing a few different places, I have also come to the conclusion that local Australian PCB manufacturers are 3 to 4 times the price of an offshore fab. So I am going to try a Chinese manufacturer.

And some people have been reading those blog entries and have been asking me to make stuff for them. I’ve given in to a few people here and there and built some. I think this indicates a clear although small demand for these devices.

So I’ve decided to have a go at manufacturing some things for sale. I’ve reviewed my designs and I think these two are obvious candidates:

1. RS232 Speed Converter
2. MIDI Clock Source

I’m going to start with the RS232 Speed Converter since that design requires the least amount of work to get it to production. I’ll post my progress here on this blog. Let’s see if I can sell something. Wish me luck!

#include <sys/time.h>

unsigned GetTickCount()
{
        struct timeval tv;
        if(gettimeofday(&tv, NULL) != 0)
                return 0;

        return (tv.tv_sec * 1000) + (tv.tv_usec / 1000);
}

Waiting for root filesystem

I’ve just spent a few torturous hours trying to get it back up again. It took me a while to figure out what was happening but it seems that the updated package for UDEV changes the GRUB configuration so it tries to mount hdb1 instead of hda1 as the root file system. Of course hdb1 does not exist on this single-drive machine so it just sits there like a moron.

Turns out it is not frozen. If you wait about 3 minutes, it will eventually come up with the following prompt:

(initfs)

I found that I can kind of get the system running by typing the following commands. These are for a single-partition system on an EXT3 file system on an IDE hard drive. If your system is different, you will need to modify them a bit:

mkdir /mnt

mount /dev/hda1 -t ext3 /mnt

chroot /mnt

login

Then log in. The next thing to do is to correct the GRUB configuration:

nano -w /boot/grub/menu.lst

Change the root=/dev/sdb1 entry to root=/dev/sda1. Once again, this is for a single IDE drive, you may need to change it if you are booting from SATA or some other kind of device.

Now regenerate the initramfs image:

dpkg-reconfigure initramfs-tools

At last we can reboot. The system came up fine for me after this.

reboot

The Etch release of Debian does not have a driver for this card built-in and even though Adaptec claim to support Linux, their drivers simply do not work unless you are running some specific outdated versions of Red Hat or SUSE. That’s not what I call Linux support!

I’m not the only one discovering this, Brent Norris wrote a wonderful article titled “Adaptec 1420SA is JUNK!” on his blog which describes pretty much the exact situation I find myself in which Adaptec just doesn’t want to know about Linux.

When are these guys (by whom I mean most major hardware manufacturers) going to realize that Linux is here to stay and is getting real popular, especially in the server room.

Anyway, enough ranting. After a couple of hours Googling around, I see that there is an open source driver available for this card and it is built into Linux kernel version 2.6.22. Debian Etch uses 2.6.18 so all I need to do is upgrade the kernel.

The easiest way to install the upgraded kernel is to get a DEB package from Debian Backports. Go to this page:

http://packages.debian.org/etch-backports/admin/

and grab a kernel, there are usually a couple of different versions available there.

Install it and reboot. Works great so far.

PS. I notice that the driver for this card was released into the Linux kernel by Red Hat corporation. So it seems even they are fed up with Adaptec’s poor support for Linux!

So I have made a little Linux app which can extract scenes from a DVD disc. The camera records each scene as a DVD “chapter”. My application reads a DVD disc and copies each chapter into a separate MPEG file. I’ll publish it here in case anyone else finds it useful.

Downloading and Compiling

I’m just releasing this as source code at the moment. I have tested it under Ubuntu 7.10 but It will probably work fine on any UNIX-based system. You can download it here:

DvdChapterExtract-1.2.tar.bz2 (16k)

You will need libdvdread and libavformat before you compile. So install those:

sudo apt-get install libdvdread-dev libavformat-dev

Next unpack and compile:

tar jxf DvdChapterExtract-1.2.tar.bz2

cd DvdChapterExtract/Release

make all

Usage

1. You need to record your discs in Video mode, not “VR” mode. VR is a Sony proprietary format which cannot be read in a regular DVD drive.

2. After recording your disc, you must Finalize it in-camera.

3. Put the disc into the DVD drive on your PC.

4. Launch the DVD chapter extract tool like so (assuming /dev/scd0 is the name of your DVD drive).

./DvdChapterExtract -d /dev/scd0

It will extract each chapter into a separate file called chapter001.mpeg, chapter002.mpeg and so on. These can be loaded directly into any video editing software.

The camera also tags each chapter with some meta-data such as the date and time the scene was recorded. I have not yet figured out how to read that data.

This blog gets around 1000 page views per day and I’ve been running the ads for about a year and a half now. In all that time Google have not paid me anything. Not a cent! So they are gone.

I can see it won’t be long before DVD drives will be an optional extra on new PCs (especially laptops) and will eventually disappear like floppy drives (remember them ?).

So it’s time to look at installing from USB on a machine which has no disc drive at all. I’ve found a few guides out there on the internet but none of them were easy to follow. I had to read several of them and then I still had to guess at stuff that wasn’t mentioned.

So here is my guide which is a little more comprehensive.

NOTE 2: I’m assuming you are logged in as a regular user. if you are logged in as root, just drop “sudo” off the beginning of all these commands.

Step 1 - Download the installation image

While there are several “small” installs for putting on a credit-card CD and so on, USB sticks are now large enough that you can use a normal install CD image. I am going to use the Debian Net Install which weighs in at around 160MB. This should easily fit on a 256MB device which quite frankly, people throw away these days because it is so uncool to have such a small device dangling from your keyring.

Go to http://www.debian.org/CD/netinst/ and download the netinst image for your platfom (if you don’t know, it’s probably i386).

Step 2 - Partition and Format the USB device

Most USB keys come pre-formatted with a FAT16 or FAT32 file system. If this is the case with your stick, just erase all the files on it and proceed to Step 3.

But of course, I had previously formatted mine with EXT3 so I’ll need to reformat it with a DOS format.

First set the partition type to DOS

sudo sfdisk -c /dev/sdb 1 c

Next, format the partition.

sudo mkdosfs /dev/sdb1

Step 3 - Obtain a kernel and RAMdisk image

Next you need an hd-install kernel and initrd image. You can download these from Debian also. For the current version of the kernel, they should be available from here:

http://ftp.debian.org/debian/dists/stable/main/installer-i386/current/images/hd-media/

Grab the two files vmlinuz and initrd.gz then mount your USB device and copy them onto it:

sudo mount /dev/sdb1 /mnt

sudo cp vmlinuz /mnt/

sudo cp initrd.gz /mnt/

Then you will need to make a file on the USB device called syslinux.cfg - just create a plain text file. Cut and paste the following two lines into it:

default vmlinuz
append initrd=initrd.gz

Step 4 - Copy the installation image

Next copy the ISO file you downloaded onto the USB device. From the commandline you can do it like this:

sudo cp debian-40r3-i386-netinst.iso /mnt/

Step 5 - Make the device bootable

You will need to have a couple of additional packages installed to do this:

sudo apt-get install syslinux mtools

Type these commands to make the stick bootable:

sudo syslinux /dev/sdb1

sudo install-mbr -r -p 1 /dev/sdb

Now you can unmount the USB device and you are good to go!

sudo umount /mnt/usb

Before you start, preheat your oven to 180°.

The Apple

• 850g Apples (I used “Pink Lady” apples but any kind would probably do)
• 2 tablespoons Brown Sugar

Core the apples, cut them in half or quarters and slice them with the skin still on. Mix the sugar with about 50ml of water and put it with the apples in a pan. Stew until soft.

The Crumble

• 175g Plain Flour
• 100g Brown Sugar
• 125g Butter
• 100g Oats
• ½ teaspoon Cinnamon

Put the oats into a food processor and lacerate them into small pieces. Then dump in the rest of the ingredients and process until it is well mixed.

Put the stewed apples into a baking dish. There was some liquid left over from the stewing, I did not drain it.

Then sprinkle the crumble over the top. Do not pack it down, you want it light and crumbly.

I baked it for about 50 minutes, it was OK but that was probably too long. Next time I’ll try about 30 minutes.

Serve with whipped cream or ice cream. You’ll get about 12 serves from these quantities.

Step 1. Install Cygwin

Go to http://www.cygwin.com/ and download setup.exe. Run it.

During the setup, you will have the opportunity to select what packages to install. Choose the following:

• binutils
• gcc-core
• bzip2
• flex
• make

Step 2. Download the compiler source code

You want binutils and gcc-core from GNU. Go to the GNU download page, choose a mirror and download the following files. Place them in your Cygwin home directory.

• binutils-2.15.tar.bz2
• gcc-core-3.4.2.tar.bz2

Yes there are more up-to-date versions but at the time of writing, the latest gcc versions do not support the 68000 platform. Feel free to try different versions but I know the versions just mentioned will work.

Step 3. Compile and install binutils

Launch Cygwin and type the following commands. Typing this kind of stuff is automatic for me these days. Its a pretty standard GNU setup procedure.

mkdir /usr/local/m68k

tar jxvf binutils-2.15.tar.bz2

cd binutils-2.15/

./configure --prefix=/usr/local/m68k --target=m68k-coff

make install

Step 4. Compile and install gcc

Same again for the C compiler.

cd ~

export PATH=$PATH:/usr/local/m68k/bin

tar jxvf gcc-core-3.4.2.tar.bz2

cd gcc-core-3.4.2/

./configure --prefix=/usr/local/m68k --target=m68k-coff --enable-languages=c

make install

Step 5. Set up your path

The 68000 compiler will be located in /usr/local/m68k/bin. To make life easier, you might like to add the following to your ~/.bashrc file:

export PATH=$PATH:/usr/local/m68k/bin

Step 6. Enjoy

Here’s the command to compile some C code:

m68k-coff-gcc -o test.out test.c

And the command to create a binary image from the compiled code:

m68k-coff-objcopy -O binary test.out test.bin

The solution ? Set up a degraded array, copy the data and then add the original disk to the array.

Put simply, a degraded array is a RAID array with one or more drives missing. RAID5 can operate with any one drive down. This is very useful if a drive fails, you can replace the faulty drive without losing any data. So we are going to pretend the drive with the data on it is ‘faulty’ so it won’t be part of the RAID until later when we miraculously ‘fix’ it.

On my machine, the new drives are /dev/sde, /dev/sdf and /dev/sdg. The drive with the data is /dev/sdh1. First we partition the new drives. You’ll need to type these two commands for each new drive:

echo ",,L" | sfdisk /dev/sde

sfdisk --change-id /dev/sd1 1 fd

You don’t have to use sfdisk, as long as you set up the partitions somehow and set them to type 0xFD (Linux RAID).

Now to create the degraded array. This is the magic bit.

mdadm --create /dev/md3 --level=5 --raid-devices=4 --spare-devices=0 /dev/sde1 /dev/sdf1 /dev/sdg1 missing

The magic word missing stands in for the drive with the data on it.

Next format the RAID array, mount the data drive and copy the data

mkfs.xfs /dev/md3

mount /dev/md3 /home/adam

mount /dev/sdh1 /mnt

cp -prv /mnt/* /home/adam/

This will take a while so you might want to do it in a screen session.

Finally, after the data is copied, we can add the data drive to the array. This is the bit where we can lose everything if it goes wrong so check your data is all on the RAID before proceeding.

umount /dev/sdh1

sfdisk --change-id /dev/sdh 1 fd

mdadm --manage /dev/md3 --add /dev/sdh1

I’m really pleased at this neat trick. I’ve now got a shiny RAID array with a total storage of 3TB. It all worked so well, I just had to blog about it!

They are so proud of it.

My solution is to mount the drives by their UUID rather than by their device node. It took me quite a bit of Googling to find an example of how to do this so I thought I’d write it here so I will know for next time.

Normally, I’d put an entry in /etc/fstab like this to mount a drive:

/dev/sdb1  /var/www  ext3  defaults  0  2

But now I change it like so:

UUID=bd412298-d540-4e4e-8f31-33ff45644bc4  /var/www  ext3  defaults  0  2

You’ll notice it is exactly the same except I have used the UUID instead of /dev/sdb1.

But wait! I hear you ask, how do you find out what your drive’s UUID is ?

Well, I have the answer for that too:

ls -l /dev/disk/by-uuid/

The problem is that the PVR150 cards sometimes register themselves as /dev/video0, 1 and 2 but other times, after a reboot they register themselves as /dev/video2, 3 and 4. I needed some way to make them stay on the same device nodes.

Enter this little UDEV rules file I wrote. It creates new device nodes called /dev/ivtvenc0, /dev/ivtvenc1 etc. up to however many cards you have. These will symlink to the correct device nodes every time. Here’s the script. Call it 010_ivtv.rules and put it in /etc/udev/rules.d/

# Rule to sort out those pesky IVTV cards which never
# seem to load in the correct order when DTV cards are
# also installed.
# by Adam Pierce 01-Feb-2008

ATTR{name}=="ivtv0 encoder MPEG",SYMLINK+="ivtvenc0"
ATTR{name}=="ivtv1 encoder MPEG",SYMLINK+="ivtvenc1"
ATTR{name}=="ivtv2 encoder MPEG",SYMLINK+="ivtvenc2"
ATTR{name}=="ivtv3 encoder MPEG",SYMLINK+="ivtvenc3"
ATTR{name}=="ivtv4 encoder MPEG",SYMLINK+="ivtvenc4"
ATTR{name}=="ivtv5 encoder MPEG",SYMLINK+="ivtvenc5"
ATTR{name}=="ivtv6 encoder MPEG",SYMLINK+="ivtvenc6"
ATTR{name}=="ivtv7 encoder MPEG",SYMLINK+="ivtvenc7"

Watch it in action. Here it is after one reboot:

# ls -l /dev/ivtv*
lrwxrwxrwx 1 root root 6 2008-02-01 13:54 /dev/ivtvenc0 -> video0
lrwxrwxrwx 1 root root 6 2008-02-01 13:54 /dev/ivtvenc1 -> video1
lrwxrwxrwx 1 root root 6 2008-02-01 13:54 /dev/ivtvenc2 -> video2

And again after the next reboot

# ls -l /dev/ivtv*
lrwxrwxrwx 1 root root 6 2008-02-01 13:54 /dev/ivtvenc0 -> video2
lrwxrwxrwx 1 root root 6 2008-02-01 13:54 /dev/ivtvenc1 -> video3
lrwxrwxrwx 1 root root 6 2008-02-01 13:54 /dev/ivtvenc2 -> video4

Now I can always rely on the ivtvenc device nodes to point at the right cards.

This solder paste stuff is pretty toxic. Perhaps I’m going overboard here but I thought some rubber gloves would be a good idea.


To apply the paste, I just squirted it on the board. It kinda went everywhere at first until I got the hang of it. Next time I’ll get a smaller tube and perhaps a smaller nozzle. I fixed it up as best I could using a toothpick and cotton tips. It took quite a lot longer and was much more messy than I anticipated.


Next comes the pick-and-place. I got most of my parts from Digi-key who send them out as “Cut tape” which is pretty convenient, you just peel the backing off the tape until you get the quantity of parts you need and the rest are left still attached to the tape so you don’t lose them in the carpet. I positioned the parts with tweezers since most of them are incredibly teeny.

My board includes both surface-mount and through-hole components. I just placed the SMT stuff at this stage because I need the back of the board to be flat for heat transfer.

Now for the fun bit. I put the loaded board onto the pan cold. Then I increased temperature to around 100°C. I left it at that heat for a minute to get everything nice and warm. Then I cranked up the heat to maximum (in my case, 175°) until the solder melted. It was magic to watch. Everything just blobbed into place. Even components which were not exactly positioned right pulled themselves into line.

After a slow cool-down over 5 minutes, I examined the board. Everything looks good to my eye except for some pretty major bridging between the pins of my ARM chip. I’ll leave dealing with these to part 3.

In the end though, I’m pretty pleased with the result. Not bad for my first try!

The idea is to use a frying pan or toaster oven to perform solder reflow for SMT circuit boards. I decided to use a skillet thinking that a toaster oven would melt components since it heats both top and bottom.

I managed to find the perfect thing. A pre-owned 9″ electric skillet from the Salvation Army shop for $3.

Believe it or not, this device is not a precision instrument. The temperature dial is simply numbered from 1 to 10. The first thing I need to do is get some idea of what actual temperature this thing gets to.


So I need to do a scientific experiment. Firstly I put some oil in the pan and stuck in a thermometer (the fork is to hold the probe in the oil). Then I turned up the heat slowly making a note of the temperature. Finally I graphed the result. Here are the results in degrees C. That cheap little temperature knob is surprisingly linear.

1. Element not energized
2. 30°
3. 46°
4. 65°
5. 90°
6. 105°
7. 125°
8. 140°
9. >150°
10. >150°

The last two entries I could not measure since the thermometer only went up to 150°C, but by extrapolation I get 155° and 175°. Yes I did this on paper, it is much quicker than using Excel!

I am now ready to use this thing for solder reflow.

DOS Emulation

First you need the very excellent DOSBOX which is a DOS emulator. You can download it from http://www.dosbox.com/.

Once DOSBOX is installed, we need somewhere to put our DOS games. I created a folder called C:\DOSGAMES for this purpose.


Now it is time to run DOSBOX. Once it is going, type the following two commands:

mount c C:\DOSGAMES\

mount d D:\ -t cdrom

NOTE: If your CD-ROM drive is not D:\, modify this accordingly.

Then you can insert your Warcraft II CD. The game can be installed like so:

D:

SETUP

Just select all the default options except for the soundcard and music device which you should set to Soundblaster 16.

Making an icon

At this point you can run the game by typing WAR2. But I don’t want to stop there. Let’s now make a pretty icon so you can launch the game with a mouse-click.

Open the folder C:\Program Files\DOSBox-0.72 and find the file dosbox.conf. Copy it to your C:\DOSGAMES\WAR2 folder.

Edit the copy of dosbox.conf and add the following line to the bottom under the [autoexec] section:

mount d D:\ -t cdrom

I’ve found it is also a good idea to reduce the speed of CPU emulation otherwise the map can scroll too fast. Modify the cycles entry in dosbox.conf like so:

cycles=20000

Now save the changes you made to dosbox.conf.

Copy the DOSBOX icon on your desktop. Rename the copy to “Warcraft II”. Now right-click on the icon and select Properties.

Enter the following text (all on one line) into the Target box:

 "C:\Program Files\DOSBox-0.72\dosbox.exe" "C:\DOSGAMES\WAR2\WAR2.EXE"
-conf "C:\DOSGAMES\WAR2\dosbox.conf" -exit -fullscreen

Then finally click on the Change Icon button.

Click Browse and navigate to the folder C:\DOSGAMES\WAR2. Double-click the file WAR2ICON.DLL.

Choose the WarCraft icon and then click OK. Click OK on the shortcut properties window also.

Now we are done. Click the WarCraft icon and enjoy!

Then I found SpamBam by Gareth Hayes. I’ve been running it for two months now and in that time I have received no spam. None. Not a single one.

If that isn’t the best anti-spam plugin ever, I’ll eat my hard drive.