***Update, This should be renamed Techno Viking Helmet***
But its October 2010 and I only just learned about the Techno Viking today. Well behind the meme curve. Whateva'
Here he is with higher production value.
Remember the Ghost Busters version.
Here he is in a 300 version (my favorite because of the McDonalds flier).
You could spend a lot of time on this project or you could do it quick and easy like I did because I was in hurry.
What it does is make the horns glow when you speak.
The helmet does this by using a volume indicator like the one that lights up a strip of LEDs on your stereo.
The structural elements of the helmet are pretty simple. I learned a great technique called tape casting from this step 4 of this great instructable. Mark Jenkins is an artist that uses tape casting.
The electrical elements are also pretty simple and cheap.
This instrutable consists of two parts; the helmet and the electronics.
First let's make the helmet because it's rad. Then we can make it awesome with voice-activated lights.
When I made this didn't know about H. Beam Piper's novel or movie. On Halloween night a little girl asked me what I was dressed as and Space Viking popped into my head.
I think The Flight of the Concords might clarify the helmet's vibe a bit:
Step 1: Making the Horns: Tape Casting
-Clear packing tape (wide transparent tape)
-Clear plastic bag
-Banana or banana shaped object...
Wrap the banana in plastic bag. This keeps the tape from sticking to the banana which lets you slide the banana out of its tape cast.
Wrap the plastic covered banana with about 3 or more layers of packing tape. Wrap tidily for tidy looking horns. Wrap about 1/2 to 2/3rds of the banana.
Now wiggle the banana out of the tape cast. The tape will be tight so wiggle the banana from side to side.
Congratulations you now have a Space Viking horn. Now make one more.
Step 2: Making the Helmet: More Tape Casting
Put a plastic bag on your head like a toque/beanie.
Wrap your head in a few layers of packing tape. Go low around the back of your head for a stable helmet.
The tape tends to crinkle as you wrap so the helmet may start to shrink away from your head. If so just cut a slit up the back and widen/adjust as needed with a layer of tape on the inside and another on the outside.
Now tape the horns onto your helmet wherever you want them.
Congratulations you now have a rad viking helmet.
Step 3: The Electric Parts
-LM386 low voltage power amplifier chip. Probably any teeny audio amp chip would work fine but this is what I had around.
-a small microphone. (I didn't have one so I used the guts of a piezoelectric buzzer as a throat mic. It was crappy because I didn't have a good throat strap)
-LM3915 volume meter chip. This senses analog voltage levels and lights up an array of LEDs accordingly.
-a 2k potentiometer
-a 10k potentiometer (the LM3915 datasheet calls for 1.24k and 8.06k resistors but I never have the right parts and I like to tweak the values.)
-4 bright LEDs. I used four for simplicity more might be better.
-1 small breadboard (I never moved this project off the breadboard)
-soldering supplies (This instructable helped me a lot)
-hookup wire (I use scraps of ethernet cable)
-a 9 volt battery (this may not be the best choice but it works)
-9 volt battery clip
-a couple of hours
Step 4: The Amp and Mic
The LM386 isn't too picky about its power supply (4v to 12v)
Power it via pin 6. Ground is pin 4. All other pins are left unconnected for better or worse.
I wired the mic to positive and to pin 3. I extended the microphone wires about 6 inches to give me some versatility.
Pin 5 of the LM386 goes out to pin 5 of the LM3915.
Step 5: The Blinky Part (with the LM3915)
I won't go into all the details of the basic setup because the datasheet does a better job.
But here are some hints:
-The outputs are active low. So connect the LEDs to + and to the chip.
-I didn't use a resistor for the LEDs.
-The input in the schematic kind of looks like pins 4 and 5 should be connected but this is not true. Instead pin 4 goes to ground.
-From the schematic I assumed that LED1 on pin 1 would light up at the lowest volume but it seemed to be for the loudest volume, kind of. It glowed weakly sometimes if I put in a bright blue LED but not with a red LED... Weird.
-I think connecting pin 9 to + is supposed to put the chip into "bar mode" (where the highest LED and all those of lower value all light up) as opposed to "dot mode" (where only one LED is on at one time). But really doing anything with pin 9 made the chip go all wambly. I ended up leaving it disconnected and this gave me the most stable result.
-I wanted both horns to light up symmetrically. But when I put 2 LEDs in parallel on the outputs one LED would be a lot brighter than the other. I should have tried putting them in series but I was in a hurry.
-Instead, I put one LED in each output and extended the wires to fit inside the horns.
-Pins 1, 9, 14,15,16,17 and 18 are all disconnected.
-Pin 10 is always on. (after some tweaking)
-Adjusting the pots on pins 7 and 8 made the LEDs light up in turn. One seemed to be for calibration and the other might be for sensitivity. Who knows.....
So the LM3915 chip took some fiddling before I got it going but it worked well enough for this Space Viking.
Step 6: Final Assembly
Tape the breadboard to the helmet.
The blue LEDs on pins 10 and 11 had longer wires so I jammed them up to the tips of the horns. The wire was stiff enough that they stayed put.
The white LEDs on pins 12 and 13 were not as bright so I taped them to the inside of the horns but facing forward so you could see them easily when I voice-activated them.
I stuffed the 9v battery into one of the horns which made the helmet a little unbalanced and slowly pulled off the horn. Nothing a little more tape couldn't fix.
Now go make your own but don't cause too much trouble.