Kinect as a Greenscreen

While looking for an old project on my hard drive, I happened to stumble upon a different project – A Kinect-enabled green-screen that I wrote months ago. The idea is it uses a user-defined threshold to determine what pixels to replace. The default is 2000mm, or 2m. Any pixel closer than that is counted as ‘foreground’, and the corresponding background-image-pixel will be replaced with the pixel from the Kinect camera. This method has a massive advantage: No special lighting, background, or equipment is needed. Not even a flat wall is needed!

Of course, I wrote the program as a proof of concept more than anything. As such, there is no option to record – It just presents the modified image in real time. In fact, many variables that are now customizable through the GUI could only be changed within the code before I rediscovered the project and decided to improve it slightly.

The code can be found here.

Of course, feel free to contribute. I’ve included a TODO list of features that I’ve neglected to add.

Shooting Down Drones With the Kinect

I’ve started working on a new project, to shoot down quadcopters and drones, primarily using an Xbox 360 Kinect. The idea started as a joke back in 2014, shortly after Amazon released its Amazon Prime Air video that went viral. A friend and I came up with the idea, as a joke, of course, to go after the drones for their items. Finally, a few weeks ago, I remembered that idea and thought it would be fun to build it.

Although it isn’t finished yet, it uses 2 nema 23 stepper motors, 2 stepper motor drivers, an Arduino Mega(way overkill) and a 24V 10A power supply. I had all these laying around from a previous project which didn’t work out. Eventually, I plan on attaching an EMP device, although the original plan was to use a HERF gun. The reason I changed my mind is because an EMP isn’t harmful against humans, and also allows me to release a lot of energy in a burst. Also, I’m going to mount a Mini ITX board on it, because right now I have to connect it to my desktop whenever I want to use it.

I wrote the code from scratch in C#. It communicates via Serial to the Arduino and uses the Kinect SDK. Furthermore, it has a graphical interface that allows me to see what the kinect sees, and also shows if it’s moving up, down, left, right, or is in the correct position already. Basically, it finds the object that is closest that is still within $minDist and $maxDist, and moves the Kinect accordingly so it is within $threshold of the center. These are the only 3 configurable variables.

I designed the frame myself, and 3D printed it. The frame mounts onto a large wooden stand that I found in my basement. It’s very sturdy, and if a part ever breaks, I can just print a new one!

The total cost of this project, so far, would be around $150, but with more appropriately sized parts, it would be possible for less than $75. These figures are in CAD and they only include the electronics/the motors. Of course, the EMP device is what will cost the most, due to the capacitor bank it will need.

I don’t ever plan on using this on drones, because that would be extremely illegal and a terrible idea in general. This is nothing more than a proof of concept and should not be attempted.

Here are some pictures and a video in operation. Due to the clutter in my room, it kept losing focus on me. Outdoors, it works much better, which is where it will be operated anyway.

Photo-2015-12-12-17-47-03_0851 Photo-2015-12-12-17-47-10_0852 Photo-2015-12-12-17-47-18_0853 Photo-2015-12-12-17-47-21_0854

Update: I have uploaded all the files to github. Currently, it is going through a major redesign. Also, I’ve created a page on Hackaday.io.

Git: https://git.scd31.com/laptopdude90/drone-defense-system

Hackaday.io: https://hackaday.io/project/8859-a-ground-based-drone-defense-system

Cooking toast on a 3D Printer

3D printers are amazing machines. They can take spools of plastic, and make virtually anything you want. But the real question is, can they cook toast?

Hi all. I had an old heated bed and matching glass that I temporarily used when my 3D printer was out of order. In theory, it could reach a temperature of 130C. Would this be enough to toast bread?

I attached some spade connectors onto the heated bed wires, which I had attached previously. Connecting the whole thing to a SLA battery, I could quickly feel it heating up. I used a piece of glass to keep it from heating up the counter top too much.

So, how did it work out?

After leaving it on the bed for around 20 minutes – 10 minutes on each side – I tried out the toast. It was warm on the outside, but the inside was still ice cold. So, unfortunately, I ended up with only slightly toasted bread.

If I wanted to improve upon my toaster, I would sandwich the toast between 2 heated beds, and I would put something heavy, like a brick, on the top. This would ensure good thermal contact, and would also keep the heat in. I think it could have worked out that way, and it would half the toasting time – the bread wouldn’t have to be flipped.

PCB Heatbed
The heated bed I used.

I Got a 3D Printer!

Hi guys!

I bought a 3D printer! I purchased it from Newegg. With tax and shipping, it cost roughly $588.

I got the Davinci 1.0a. According to the internet, it has a few minor problems that could easily be fixed. When I got mine, I didn’t have any problems and it worked perfectly. Still, I installed Repetier firmware so I could use my own filament rolls.

I have ordered a 1kg each of red, orange, green, and glow in the dark filament.

Already, I’ve printed out a calibration board, a key chain, a pan/tilt servo camera mount, and replacement parts for the 3D printer in case it breaks. Currently, I am printing a spool holder for the extra spools, which are supposed to arrive tomorrow.

Using a cheap HDMI to VGA converter with a Chromecast

Hey all! A got a Chromecast for Christmas, which I was happy about, but my projector doesn’t have an HDMI port. Doing some research, it seemed nobody documented which adapters do and do not work with the Chromecast. I found a cheap $10 one on Ebay, pictured above. It has no power input, which worried me, because that often means it is not an ‘active’ type converter.

It came in the mail today. I hooked everything up, and sure enough, it worked! I’m linking the actual Ebay item, so you can buy the same one and be sure it works.

Link