I think it's very interesting, but I suspect too few people have anything to contribute.

I know I don't have anything smart to say about this specific subject, and I usually try to follow the old german saying "Selig sind die, sie nicht zu sagen haben und trotzdem schweigen" (hope I got it right - I don't actually speak german), which means "Blessed be those, who have nothing to say and nevertheless remain silent..."

Discussion about my previous project: https://news.ycombinator.com/item?id=16756901 was much bigger in comparison with this project - this is surprising me.

Probably just timing. I find it pretty cool, but I have nothing to say. I'm impressed with the work and would like to do the same myself, but I'm not sure immediately where I'd use this and when I'll have time. I've put it in the section of my brain where I keep things for "when I'll need it, go look this crazy ambitious project".

If I can provide more feedback, while looking at your project, I had the following thoughts:

  - This is super impressive.
  - I'm thankful that people spend time making technology 
  opensource.
  - I'm sure this will grow over time and more "complex" 
  technology will become open this way.
  - I'm curious in which context the author decided to 
  dedicate that much time to this cause (probably in 
  academia? or someone with access to a lab and a lot of 
  experience in all the fields involved in this project).

Thank you for reply!

German native speaker here, you just got two letters wrong:

Selig sind die, die nichts zu sagen haben und trotzdem schweigen

Thanks.

I was under the impression that it a well known saying when I first heard it, but google doesn't come up with many hits for me (and some with wrong spelling) - likely because of my google bubble / history.

Is this a common/well-known saying?

I heard it before, but it is not very commonly used. It is a bit more like a literaric aphorism than something people would use in any everyday conversation.

On the contrary - it's super interesting! I definitely want to come back to it and study this and thinking of projects I can use it on for fun and no profit, but also know that though I have analysed lidar data, I have very superficial understanding of the technical details of implementation. For me this is not just great as a cheap lidar implementation but a great working example to learn on.

Honestly, I didn't open comments and simply added it to my "come back later" list, because it looks very very interesting to me, and would need to read it in detail. Great work, btw!

Thank you so much for releasing this. I have several personal projects were this can be useful.

One variation I’m thinking about and want your opinion on. I’m building a circuit that VERY precisely (think <1ms accuracy) marks the start and end of when a high speed object passes the field of view. The exact scenario is a bit hard to describe if you aren’t familiar with the subject area, but an analogy that works well is imagine having two sets of cones laid out on the ground with 10 meters between the groups. Then imagine a car doing 100mph between the two sets of cones. What I need to be able to answer is:

- did the car go between the first set of two cones?

- what’s the exact time it went between them?

- did the car go between the second set of two cones?

- what’s the precise time it went through the second set?

- what’s the calculated speed between the two sets?

The real scenario isn’t touching the ground, so anything pressure sensitive doesn’t work. I’ve been currently experimenting with using lasers on both the start and end gates and an fpga doing the calculations, but I’d love if I could do this with a single laser setup using a scanning setup like yours.

Can you speak to how hard it would be to use something like this to precisely (1ms or better accuracy) measure a low flying object between a starting and ending point?

I am not the OP. Seems like you should be able to set up two break beam detectors: one per set of cones. Process detector output into digital form where you get a pulse when the detector is broken. Connect them to a microcontroller input and use a fast counter in input capture/compare mode to measure time between pulses. A counter running at 1 MHz (1 us) should do.

I find it super interesting - but it's beyond my capability to contribute so I keep quiet for the moment. I imagine many people would be doing the same.