Team140.com

I know it’s been a while since I’ve made an update. I’ve been busy! Last week I had to set up four new employees with computer equipment and when Saturday rolled around things got really hectic!

I got a call bright and early on Saturday and was asked if  I could head to Monroe County which is about 2 and a half hours away to run sonar to help find a drowning victim. A page went out to rustle up a full sonar crew and we headed out. We get to the scene and find out a 15 year old had been swimming in the Buttahatchie river with two friends, struggled with the current and was last seen about 50 yards from the bridge they were swimming near.

We made several passes with the sonar and had to stop the search due to a torrential downpour. During this time I reviewed all of the sonar images and found what looked to be a person laying on their side up against debris underwater. Nothing else we scanned resembled anything like a body. There are several factors about running sonar in a river that makes getting a result very difficult. For one, rivers are FULL of debris. The more debris there is, the more likely the debris is in the line of sight of the sonar. Also, since interpreting sonar images takes some creativity in picking out patterns it is also easy to look at a log with branches and interpret it as a body. The last factor with running sonar in a river is the dead area under the towfish. The towfish is a torpedo-like sensor that is pulled under water. Since the sonar can’t see directly below it, there is a good possibility that you could run right over the top of something and never see it. In open water you can direct the boat in a pattern to cover the entire floor, but you cannot do this in a narrow river.

The search continued and divers weren’t allowed to enter the area of the sonar hit due to the high current. A couple of days later when the flood waters receeded, divers were able to reach the potential hit and found out it was a 6 foot long piece of carpet rolled up and was up against a submerged tree.

After hearing this news I wanted to make another sonar run to hopefully locate the victim. We had a boat operator that knew the river very well and were able to position the boat and the towfish so we could see areas we weren’t able to see before. After about an hour on the river we came back to review the images. A few interesting items were marked so we left the authorites on scene the location of these items and came back home.

None of the interesting items turned out to be the victim, but the use of sonar was able to image the river floor and rule out the areas of interest they had from looking at the river from above.

Sonar isn’t perfect, but it is one great advantage that not a lot of teams have and we’re grateful for it. We have located submerged vehicles, drowning victims and other submerged items that would have taken much, much longer for divers alone to find.

They recovered the drowning victim early this morning. The family can now have the closure they need.

I have some tricks up my sleeve to try and make the sonar imaging work better in the narrow channels of a river. I’ll be exploring them in the upcoming months.

This weekend? I’ll be camping at Arkabutla Lake and patrolling the lake with my SAR unit.

A few members of our team have been tasked with putting together a survival kit that can be dropped from a helicopter during a rescue.

This was prompted by a rescue where the victims were in some extremely difficult terrain for our area. They were surrounded by waist deep swamp, an impassable river and extremely thick forestation. Mother Nature did her best to delay our efforts, but in the end everything turned out OK. Like every mission we go on, we broke it down afterward to find out if there was anything we can do in the future to make contact with and extract the victims any sooner.

One of the ideas we came up with was a survival/contact kit that could be dropped from a helicopter into the dense wooded areas where we are usually called out to. We tossed around the idea and have come up with a couple of rough plans for a kit.

There are companies that specialize in droppable survival kits, but they are geared toward mountain rescue where help may not be able to arrive for a day or more. Those kits are more survival than they are comfort/contact, which is our plan.

The two kits we have in mind are as such:

Soft Droppable Kit

• XL Sleeping bag
• Military MRE (meal)
• Flashlight
• Minimal First Aid Kit
• 2 Bottles of water
• 2 firemaking devices (matches and lighter)
• Garmin Rino (two way radio + GPS)
• Pre paid cell phone
• Bug spray
• Strobe light (for location in the dark)

The contents of the Soft kit will be bundled in the center of the sleeping bag and then the sleeping bag inserted into a waterproof vinyl bag.

Hard Droppable Kit

• Same items above, except space blankets instead of sleeping bag.

The Hard Droppable Kit would use a Pelican case as they’re supposed to be “bomb proof” and should survive a drop from a helicopter.

We’re in the very early planning stages on this and will hopefully be able to do some drop tests in a month’s time. When we do, I’ll be sure to take photos and video.

Do you remember anything from your egg drop tests in school? Do you have any ideas to make the kit safe from damage when it hits? I appreciate any comments or suggestions and they’ll be added to our upcoming brainstorming session.

First off, let me first apologize to the vintage TV purists out there. I know there are very few of these televisions left out there and most aren’t as nice looking as this TV. Parts are hard to find and even if I did revive it, even though it’s nostalgic, I wouldn’t enjoy watching it every day.

I bought the TV a couple of years ago at an auction just because I loved the way it looked. When I got home, I plugged the TV in hoping to see an image on the screen but was instead met with a blank screen but fantastic sounding audio. I was slightly disappointed, but what do you expect for a as-is, where-is sale? I shuffled it into a spare room where it sat for all that time. As you can see from the picture to the right, it was a TV, but also a TV stand in itself! That’s no way for a classic RCA to live…

I started looking around for a tube 4:3 TV that I could house in the RCA cabinet that preferrably had HD abilities. Sadly, my search to find the right picture tube never panned out. I wound up waiting too late to search and now all the store shelves are loaded up with widescreen LCDs. You’re lucky if you can find a tube TV now. Seeing the state of things on the shelves I decided to drop the tube TV idea and move on the replacing the tube with an LCD.

In my Multi Touch table project, I’m using a Dell 23″ widescreen LCDso I grabbed it and laid it up against the RCA’s screen. Hmm… with a little bit of modification, I can put the widescreen LCD in there!

Let the hacking begin!

I started out by removing the guts of the TV. As you can see in the picture to the left, it had a lot of guts! Heavy, too.

While playing mad scientist in the back of the TV, I found a ring on the tail end of the TV tube that had broken loose and was just flopping around. That’s probably what the problem was, but I was on a mission!

I removed everything you see in the photo, the mass of tubes on the bottom of the cabinet, the tuning assembly on the left and the picture tube itself.

Once the case was gutted, I took the tube fascia off and marked where to make the cuts so the LCD panel would fit. I had hoped to leave a few of the original tube support mounts to use to secure the LCD, but due to it’s width they had to go.

An air powered auto body saw made very short work of the heavy duty steel that the fascia was made of. It cut through it like butter. I was able to cut right up to the tape line nice and smooth without even disturbing the tape!

Once I had the fascia trimmed, I dropped the LCD into place to make sure everything would fit. It fits like a glove!

Since it was rather late at night to go parts shopping, I grabbed a few lengths of wire, some electrical tape and an old pair of black slacks I’ve never worn and put them to use.

I strapped the LCD to the case with the wire and cut strips from the slacks to lay over the top and bottom edges of the LCD to act as a blackout cloth since the fascia and the LCD don’t mate up completely.

I had planned on making a run to Lowes to pick up something proper to strap the LCD in with, but it is Mother’s Day after all. I’ll stop by the hardware store sometime this week and finish up the LCD mounting.

I’ve still got a little bit of work to do with this to be complete. Here’s a short list:

• Set up the dedicated PC. It will be a Dell Dimension 4700 2.8GHz machine. Needs a video card upgrade first.
• Mount the IR remote control receiver. This should be pretty straight forward.
• Mount an external DVD writer in the case. See that funny looking panel with the “RCA Victor” and chevron on it? That’s a flip down access panel. The drive is going behind that!
• Audio. I need to do something about sound. I’m thinking a small amp to drive the stock speakers. They sound awesome!

After all of that, the RCA Victor Media Center should be complete! Here’s a few more shots showing the finished product. I’ve succeeded in turning a vintage 1957 Console TV into a high definition media center capable of playing 1080p content for just about $300!

As you can see from the video above, the multi touch table lives! I spent the most part of the weekend laying out the lasers and taping off sections of the plexiglass that were allowing the camera to pick up my movements that were not wanted, but last night I was finally able to use the table and get the touch responses I wanted.

I started out Saturday afternoon with a trip to Lowes for some plexiglass, some electrical tape and some other odds and ends I thought I would use. I used one sheet of plexiglass to support the LCD matrix and then moved on to extending the LCD backlight wires.

Not to self: Don’t extend the LCD backlight wires! I used a heavy gauge wire to extend the leads, but apprently the LCD sees the difference in resistance and shuts down the light. Boo. I can still deal with the length though.

So, from the ground up we have:
LCD Backlight
PS3 Eye USB camera
Electronics for LCD (hanging between LCD and light)
LCD panel
4x 25mw IR lasers with a 120* diffuser

Let’s take this layer by layer and go over the what to do and what NOT to do…

LCD Backlight
Not much to say about this. Keep the diffuser and fresnel in place. It makes the light a tad softer, but more of it.

PS3 Eye USB Camera
I broke my first one. I had it completely modded, then I manhandled it one too many times. Best Buy to the rescue. You’ll have to disassemble the camera, carve out the IR filter in the lens assembly, then install a 780nm bandpass filter. This filter blocks EVERYTHING except light in the 780nm range. Not much else to make note of or mod here.

Electronics for LCD
I made no changes to the electronics. One is the power supply and the other is the input circuit. No real way to extend the distance between the backlight and LCD without some special wires. I can deal with this.

LCD Panel
You have the be VERY careful with this. If you break this, you just lost the main part of your table. Everything else can be replaced cheaply or hacked pretty quick. No real modifications here. For the prototype, there is a 1/4″ thick piece of plexiglass supporting it.

780nm IR Lasers
I have four of these guys rated at 25mw, which I found out is about 5 times more powerful than needed. Oops! They each have a 120* diffuser installed which turns that pinpoint light into a straight line. Some notes about the lasers – make sure they are collimated (focused) BEFORE you try and use the project. If not, the IR laser will light up your whole hand and not just your fingertips. It will drive you crazy. I had to make sure the laser light plane was as close to the LCD screen as possible and parallel to the surface. A few mad scientist moments later with electrical tape and I was set!

Initially I had collimation issues with the lasers. Problems like… I forgot to do it in the first place! After tuning each laser to provide a 1mm pinpoint from two feet away I installed the 120* diffusers and aligned them with the plane of the LCD.

With the lasers in place, camera positioned and the system turned on I proceeded to calibrate the system. The calibration screen is like most other touch display calibrations. It displays a grid of crosshairs you must touch in sequence to calibrate the screen.

This is it… time for the final test!

I fired up the tracking software and opened a few demos. SUCCESS! The screen responds to your touch and there doesn’t appear to be much lag, if any at all. It can track up to 12 or so fingers at a time before crashing, but I think this is due to a Windows 7 x64 or CPU issue. I’m running a crappy Dell 1501 with an AMD processor and it’s not the fastest thing in the world.

That’s where I’m at. The prototype is finished and now it’s time to move on to the table itself. I’ll post a ton of pictures and more videos of the table when it’s finished completely!