Ask HN: Seeking ideas for preschool/school projects

Wow!

So cool, I want one. Watch the video here (1) it gets really neat at 1:43.

I want to do this.

For this who don’t know, cheap projectors these days are quite decent. I got one for $75 and we use it as the main screen for the kids. During very sunny days it does not work well, which is a benefit. If it’s too bright to watch TV then go outside! I have one like this and I love it, plenty of other vowel-poor companies make similar. (2)

There is also a makers magazine that has all kinds of ideas. Pretty cheap through discount magazine. https://makezine.com/

1 https://web.cs.ucdavis.edu/~okreylos/ResDev/SARndbox/

2 https://meh.com/forum/topics/vankyo-performance-v600-native-...

3 system 76 instructable https://www.instructables.com/Augmented-Reality-Sandbox/

One of the things that I always messed up when calibrating it, is the step using the CD-on-a-stick part. You need to do this calibration phase changing the z axis on different points. Do one low. Do one medium, do some 'high'. This is how the system defines it's 'skew' of projection when it comes to the different heights/levels -- and if you do this step all roughly on the same 'z' plane, it will work, but it will not be anywhere near as accurate / magical feeling. The instructions I believe are hazy on this critical part of the setup.

We always used blocks / things covered with white rags instead of sand. Far easier to justify building over the living room table this way, and makes for a quick clean up process!

It's 100% super cool. Also, as you said, we use an $89 3 years ago projector. It is NOT a short-throw projector, but mounted roughly 6-7' above the surface. The kinect was mounted on a yard-stick hanging slightly down below so it's field of view covers just that of the table itself.

It's a super neat end result; and can be decently frustrating during the calibration phases and software setup, but is worth it!