Here’s the video screen attached to my harness while the camera’s filming another one of our characters.

Sorry, I don’t have more photos. I’ll try to get some taken next time we film.

(original post: Learning Puppetry tech…)

One of the problems I have when I’m puppeteering Rudy Monster is that I’m stuck underneath his huge furry body and it’s really difficult to see the monitors that Kay and Jen are using to watch their own performances. So I started thinking about how to give myself a small, portable monitor that I could use while I was under Rudy.

I’d read about Caroll Spinney’s “electronic bra” that he wears inside of Big Bird, but that has a fairly large CRT video monitor on it, and I was sure that modern technology could provide me with something much, much better.

The video glasses that wouldn’t work…

At first, I tried using a pair of Video Glasses.  I figured that I could just wear these on my face and I would be able to puppeteer with the best of them. Unfortunately, I hadn’t counted on two things, the first logistical, and the second technical. First, with these glasses on, I couldn’t see anything but what the camera was showing me. No script, no other puppeteers, no nothing. I was trapped inside the glasses until I took them off.

Second, and much more importantly, they only worked for ten minutes at a time, and then they conked out. If I let them rest for a half hour or so, they’d work again, but I couldn’t afford to only get 10-20 minutes of use out of every hour; I needed to be able to use these for long puppeteering sessions. So I scrapped the glasses and went back to puppeteering blind.

But, of course, that didn’t work very well, either. I constantly had to get coaching from my coworkers about Rudy’s eye focus, and I had to feel my way through everything. Not the way I like to puppeteer.

Finally, I decided to build my own rig to approximate what Caroll Spinney has.  Looking at the pictures of Caroll’s getup, I started figuring out how I could get the appropriate parts. Of course, trying to get a CRT video monitor these days is nigh-impossible, but I found links to LCD flat-screen monitors that have the same 16:9 aspect ratio (widescreen) that our camera has. These screens were being sold for retrofitting cars that didn’t have backup cameras with aftermarket cameras.

And then I saw a related link for a wireless transmitter that allowed you to transmit video from your camera at the back of your car to your monitor on your dashboard, without wires. This was what I needed.

So I got the following equipment:

• a 4.3 Inch LCD TFT Rearview Monitor screen for Car Backup Camera ($15.62) to strap to my chest
• a 2.4G Wireless Color Video Transmitter and Receiver for a Vehicle Backup Camera/Front Car Camera ($10.69) to give me a wireless connection between the camera and my chest
• a Rechargeable 6000mAh / 12V DC Portable Lithium Ion Battery Pack ($29.99) so I wouldn’t need to be plugged in while I was operating my puppet
• a 12V DC Power Adapter Supply ($5) to power the transmitter for the wireless connection (though, in retrospect, I could have used the charger for the Li-ion battery pack to power the transmitter while I was using it, so I could have shaved $5 off this build)
• a CamKix Chest Mount Harness ($11.99) to hold the whole thing to my chest. I thought about building one from scratch, but for twelve bucks? I didn’t think I could do it cheaper.
• and a package of 20 2.1×5.5mm Female and Male DC Power Adapter Connectors ($4.90) to make the connections neat (I probably could have bought just one male and one female, but I figured I might do this more in the future). The great thing about these connectors is that they didn’t require soldering; they had screws.

First I tested the monitor and the battery. Both had all the connectors they needed, so I was able to take the Y-splitter lead that came with the battery and plug one end into the monitor’s power cable and the other into the power supply that came with the battery. I plugged in the video RCA out from our camera and… voilá! I was watching what the camera was recording on the tiny monitor. At the very least, my getup would work if it was hardwired.

Next, I wanted to get the wireless transmission working. The pieces of the wireless transmitter were meant to be hardwired into a car, so they had bare wires as power leads. I was prepared for this (remember, I bought the package of connectors), but then I had a sudden thought: this was DC power, and unlike AC power, with DC power, polarity matters. With my misadventures in LED wiring still fresh in my mind, I popped off to Google to make sure I had my polarity correct. Finding the Wiring Color Codes reference in the free electrical engineering textbook “Lessons in Electric Circuits“, I read the following (the last sentence was bolded by me):

US DC power: The US National Electrical Code (for both AC and DC) mandates that the grounded neutral conductor of a power system be white or grey. The protective ground must be bare, green or green-yellow striped. Hot (active) wires may be any other colors except these. However, common practice (per local electrical inspectors) is for the first hot (live or active) wire to be black and the second hot to be red. The recommendations in Table below are by Wiles. [JWi] He makes no recommendation for ungrounded power system colors. Usage of the ungrounded system is discouraged for safety. However, red (+) and black (-) follows the coloring of the grounded systems in the table.

Ok, so these red wires were positive, and the black wires were negative. And… oh, lovely! This wiring diagram for the product even states that! This is what I get for not reading the documentation before diving in…

Documentation? How quaint…

So I hooked up a female DC power connector to the transmitter’s power, making sure the red wire was going into the positive terminal (then screwing it down with a #0 phillips head) and the black wire was going into the negative terminal (screw, screw, screw). Then I plugged the male power plug from the extra power supply I got and saw the little indicator light on the transmitter light up.

So far, so good.

I did the same with a male CD power connector on the receiver’s power, and then plugged it into the the Y-splitter lead that came with the battery.

I picked the male power connector because the battery pack had a female power port, and the monitor had a female power plug.  This meant that the cable above would let me plug in a male plug and not have to wire up anything special.

And when I turned on the battery, the indicator light on the receiver lit up.  So, holding my breath, I plugged in our camera to the transmitter… and… success!

I was so excited, I put on the harness and took the screen upstairs to my wife.

“What’s that?” she asked, indicating the picture on the diminutive screen.

“That’s the sewing machine. Downstairs.”

I’ll post a picture of this rig in action after we film with it this coming Sunday, but I couldn’t wait to post about assembling this setup.  It felt good.