This reminds me of Metal Gear Solid. And Skynet. Clicky.
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How-To: Make a Cheezy Flashing Stocking
NOW WITH 100% MORE PICTURES!!
This is a good small (and simple) project for those of you wishing to get a little crafty this holiday season and get some nice hands-on experience with circuits. I’ll detail how to make (or retrofit) a stocking with flashing LEDs, complete with schematic, BoM (Bill of Materials) and seemingly expert article writing skills.
Schematic and Theory
[Turns out I published this without the schematic section in place. I'll upload that... sometime.]
Prototyping
Now that we understand, or pretend to understand, how the circuit functions, let’s prototype it. It works all nice and dandy in the computer, but let’s see what physics has to say about it.
If you have a breadboard, it’ll make your life much easier. RadioTent™ usually has them for $5-10. Prototyping boards have connections across each row, typically with five columns per row. Power and ground connections are all connected in their respective strips.
Bird's-eye view of the circuit.
Here’s another shot with the second set of LEDs on:
Red LEDs; side view. Click for full resolution.
Fabrication
Time to start putting your components into their final destination. You could use the same prototyping board you used before, but if you used a breadboard you’re going to have to get something else. I didn’t want to pay RadioTent™ $10 for a 3″x3″ piece of plastic, so I improvised:
Pro Tip: Don't have a printed circuit board or prototype board? Cereal boxes make a great foundation! Click for full resolution.
This is a gingerbread man decoration. I was testing to see if I needed an LED mount. If you cut the hole small and then push the LED through, it should be quite snug.
I punched a hole into my gingerbread man decoration for the LED.
Once you’re comfortable with your circuit, the tricky part begins. Especially if you’re recycling a cereal box. Start by using a sharp knife or scissors to punch small holes into the cardboard in the shape of each component’s footprint. Try to lay things out logically so you won’t have to run too many extra wires.
Starting to populate the final circuit board.
I used the side of cardboard with wax on it as the back of the board (the formerly outside of the box). It made it slightly easier to clean up any solder.
Reverse side of my improv circuit board.
Once you’re done populating (and testing!) the finished board, you’ll probably want to shield the board. Do this for a couple of reasons.
- An unshielded board will have sharp wires on the back which could cut through the stocking.
- Shielding the board protects it from anything being placed in the stocking.
- Gives you an excuse to use a staple gun.
My ‘shielding’ is just some clear and semi-hard plastic that my decorations came attached to. I stapled them to the board. Make sure you don’t punch through a wire or worse, a component!
Finished circuit board with shielding.
Next, turn the stocking inside out to cut holes in the stocking. I’d lay out any decorations that you have (but in reverse) to help you with spacing.
Planning out where to punch holes in the stocking for the LEDs.
If you’ve got all your LEDs in place, fire up a hot-glue gun and put a drop at the base of each LED. Also slather some on the back of the circuit board to keep it steady.
Internal mounting is done.
It’s time to flip the stocking again so it’s right-side out. Take this step slowly and carefully so that you don’t rip a wire out. Once you’re done, hook the battery up and make sure it’s functioning.
Testing the stocking to make sure nothing was busted from the flip.
The second half of the cycle, all LEDs are functioning!
Last step! Punch holes in all of your decorations (as I write this, I realize a hole puncher would probably work really good…) and then hot-glue them into place.
Hang the stocking and bask in all of its glory!
Final stocking; first half of circuit cycle.
Final stocking; second half of circuit cycle.
Additional directory access via FTP with chroot enabled
Problem: We want to access a folder outside of our user’s home directory via FTP, but we don’t necessarily want to give the user full access to the server.
Solution: We need to link the desired directory that is outside of the home directory to a folder that IS in the home directory. For more awesomeness, we’re going to skip the one-shot solution and make the server link the two directories automatically every time it starts.
Let’s do this: If you are not accessing the server locally: Download PuTTY, run it and access the server. If you are, just open a terminal session. Either way, log in once you have access.
Let’s get MCEdit, which is by and large much easier to work with than VI, Ubuntu Server 10.04′s default editor:
sudo apt-get install mc
Now let’s link a folder that we want to access outside of our home directory. For example, I want to access my webserver folder, /var/www/, with the user bob’s ftp access. We still want to leave chroot_local_user=YES to restrict the user to their home directory because it’s more secure. First, let’s make a new folder for bob that will mimic /var/www/ in his home folder.
sudo mkdir /home/bob/www
And now, to permanently associate the new folder with the desired folder, we need to mount the association every time the server starts. Let’s edit fstab.
sudo mcedit /etc/fstab
A blue screen of text editing goodness should appear. Add the following line to link the actual webserver directory to our newly created folder. Press Tab to change to the next column.
/var/www /home/bob/www auto bind 0 0
Adding the folder association for bob.
Those are zeros, by the way. This additional line tells the server to link /var/www/ to /home/bob/www and to automatically figure out the file system. It also doesn’t care about backups or checking for errors. Once this line is added, press F2 and Enter to save, then F10 to exit.
The only thing left to do is restart the server.
sudo reboot
FTP into the server after it’s done restarting to see if the commands worked. You may need to play around with permissions if you can see the new directory but cannot modify it or its contents.
Challenge Mode: Same requirement as above, but with a different drive.
Let’s do this: We need to do the same commands as above, but this time we need to associate the second HDD with the folder in the home directory. To find out what the second hard drive shows up as, type:
sudo fdisk -l
This should produce a list of drives and their partitions and sizes. Match up the drive sizes with the one you’re looking for to get it’s mount path. We need to find out what the UUID of the second drive is. Replace /dev/sda2 with whatever you deduced your drive is from the fdisk command above.
sudo blkid -o value -s UUID /dev/sda2
The fdisk command and UUID listing command is detailed below, with the UUID command highlighted:
This command shows the specified drive's UUID.
And now let’s edit fstab with the correct drive association. This time, use “defaults,errors=remount-ro” instead of “bind”. You can leave the first zero as zero, but change the last zero to a one.
The last line shows the drive association with UUID.
Restart, and then check it out.
Moosalo Red Ale
I’ve named the Irish Red:
Click for full resolution.
Force Latte
Click for full resolution.
I’ve been wanting to do this one for quite some time. Mainly because of Yoda’s dialog.
I was considering doing a cloaked Yoda on the last panel since I’m not skilled enough it’s not typically my style to draw in detail, but in order to do the comic justice I changed my mind.
Useless toast: Yoda’s actual height on the comic is about an inch and a half.