Hacker News: waerhert

New comment by waerhert in "Show HN: Neural Particle Automata"

waerhert — Tue, 23 Jun 2026 13:41:16 +0000

On the outside it looks very similar to what Michael Levin found on electrical communication between living cells. There too, the organism's cells were able to structure and repair their larger-scale morphology: https://www.youtube.com/watch?v=XheAMrS8Q1c

New comment by waerhert in "Making Ferrite Core Inductors at Home"

waerhert — Sat, 07 Feb 2026 01:11:16 +0000

Agreed! And also,

  Total capacitance in series is 1/C1 + 1/C2, while in parallel is C1 + C2.
  Total inductance in series is L1 + L2, while in parallel is 1/L1 + 1/L2

New comment by waerhert in "Sandboxing AI Agents in Linux"

waerhert — Tue, 03 Feb 2026 23:28:30 +0000

Nice approach! On Ubuntu 24.04 I had to loosen some AppArmor protections by creating a file:

  > cat /etc/apparmor.d/bwrap 
  #include                                                        
                                                                                  
  /usr/bin/bwrap flags=(unconfined) {                                              
    userns,                                                                        
  }

New comment by waerhert in "Lessons learned shipping 500 units of my first hardware product"

waerhert — Tue, 03 Feb 2026 22:58:45 +0000

Great read, thanks for sharing this. I'm also coming from software and have recently started making some hardware for personal use in my free time. The idea of selling it as an actual product has occurred to me, but the thought of dealing with all the logistics quickly makes me reconsider. Congrats on your launch!

Receiving Natural VLF Radio Signals

waerhert — Sun, 18 Jan 2026 10:19:40 +0000

Article URL: https://www.qsl.net/2e0waw/radio/radio-vlf.htm

Comments URL: https://news.ycombinator.com/item?id=46666538

Points: 2

# Comments: 1

New comment by waerhert in "Ask HN: Share your personal website"

waerhert — Fri, 16 Jan 2026 20:37:40 +0000

https://svendewaerhert.com/blog/

New comment by waerhert in "Fix HDMI-CEC weirdness with a Raspberry Pi and a $7 cable"

waerhert — Mon, 15 Dec 2025 23:43:38 +0000

Isn't DDC the I2C bus? Interesting article about that here: https://mitxela.com/projects/ddc-oled

New comment by waerhert in "The tiniest yet real telescope I've built"

waerhert — Fri, 12 Dec 2025 09:55:57 +0000

Very cool, thanks for sharing! Any ideas of adding 2 gimbal motors to this for GOTO? MS6010v3 or something lighter would seem like a good fit.

Optical guitar pickup for nylon strings using fork light barriers

waerhert — Tue, 02 Dec 2025 12:40:55 +0000

Article URL: https://codeberg.org/Luno/KlimperLux

Comments URL: https://news.ycombinator.com/item?id=46120629

Points: 4

# Comments: 1

New comment by waerhert in "Nearby peer discovery without GPS using environmental fingerprints"

waerhert — Tue, 25 Nov 2025 17:00:22 +0000

It's not limited to WiFi networks and indeed the fingerprints you suggest would be a lot better because they would change significantly over time. The whole WiFi networks idea kinda stuck because it's an obvious an easy thing to grab from the environment using a mobile phone. An audio fingerprint would definitely be doable on mobile.

New comment by waerhert in "Nearby peer discovery without GPS using environmental fingerprints"

waerhert — Tue, 25 Nov 2025 16:25:22 +0000

I see, this sheds some new light on your initial concerns. I'm aware an attacker can keep pretending to be inside an environment once they've seen it. I wasn't accounting for a scenario where an attacker has a huge database for queries like coords -> list of wifi networks. I was under the assumption services like Wigle only provided the reverse lookup (wifi -> coords). Indeed an attacker could potentially reverse the LSH tags if it hashed the wifi environment within very small geofences. It's bit of a needle & haystack problem but not an impossible one with enough resources. I wouldn't say it's a perfect system and I don't mind it falling apart under scrutiny, I just found it an interesting idea so I really appreciate you thinking along here.

Edit: Maybe some preshared group hash (kinda beats the point), or combining multiple modalities (eg bluetooth, shared interests) or some kind of proof of work token could help mitigate some of these issues. I guess anything to reduce the time to attack helps in this case? Or anything that really pins down environment + time, like what smath described in his comment. In essence, the core idea of minhash + lsh works and it doesn't limit you to just wifi networks. The key is being able to grab a fingerprint that is unique enough and different enough each epoch. Wifi networks are just easy enough to grab vs something more low level like an APs beacon timing interval jitter or something.

New comment by waerhert in "Nearby peer discovery without GPS using environmental fingerprints"

waerhert — Tue, 25 Nov 2025 15:31:48 +0000

Thanks for the heads up! Good to know what's out there. Interesting that I independently arrived at something possibly similar.

New comment by waerhert in "Nearby peer discovery without GPS using environmental fingerprints"

waerhert — Tue, 25 Nov 2025 15:15:08 +0000

Thanks for the feedback! Rainbow tables probably won't work here since the epoch (rounded to 5 minutes) salts everything, so precomputed tables would expire constantly. You would use use BSSIDs + SSID in real implementations. The MinHash part creates 128 hash values from the entire observed set, not a subset of 3, then LSH divides these into bands where similar sets collide probabilistically based on Jaccard similarity. I've tested with two phones where one saw 3-4 networks and the other saw ~10. They still found each other, and you can try it in the interactive demo yourself. You're right it's not entirely privacy preserving, really depends on your threat model as I discuss in the security section. Your idea about combining area hints with time-based salts is interesting though, feels like it could bridge geospatial indexing with this approach! The whole geospatial indexing thing was something I became aware of late in the project and didn't go into further. It's probably a much simpler approach if geolocation is important. In the current approach, geolocation doesn't matter at all, only 'the environment', whatever that may be.

Nearby peer discovery without GPS using environmental fingerprints

waerhert — Fri, 21 Nov 2025 11:47:38 +0000

Article URL: https://www.svendewaerhert.com/blog/nearby-peer-discovery/

Comments URL: https://news.ycombinator.com/item?id=46003606

Points: 78

# Comments: 23

New comment by waerhert in "A statistical analysis of Rotten Tomatoes"

waerhert — Thu, 21 Aug 2025 09:06:54 +0000

My immediate thought after seeing the first chart was that it is inversely related to my own experience with movies in the last 20 years. Maybe there's an idea in there for a 'score normalizing' browser extension.

New comment by waerhert in "Custom telescope mount using harmonic drives and ESP32"

waerhert — Tue, 19 Aug 2025 23:44:14 +0000

Works great on cheeses too!

New comment by waerhert in "Custom telescope mount using harmonic drives and ESP32"

waerhert — Tue, 19 Aug 2025 23:36:34 +0000

OnStepX is very much pulse based as far as I understand it. I haven't encountered offloading techniques like you mentioned yet. Since both motors support (multiturn) positon modes, it should be possible to completely forego the pulsebased approach and only drive the motors using regular (and less frequent in comparison to pulses) position instructions over CANBUS. I spent some time reading the code in OnStepX to understand how to implement it in this way but hooking it up in pulsemode was just too easy to get started.

New comment by waerhert in "Custom telescope mount using harmonic drives and ESP32"

waerhert — Tue, 19 Aug 2025 23:23:46 +0000

Indeed the cost is mainly from assembly. The board itself is 2 layers, all default settings at Jlcpcb except for the color which is now black as opposed to the default green. This increases the cost of the board a bit. You can experiment with their calculator to find out more. I've ordered 5x each version, which is also the minimal order amount. I did try to stick to the standard library as much as possible but it's not easy once you go beyond standard passive components. Can't currently tell the exact difference it would made if I had soldered the THT by myself, likely not enough for me to bother. You could be right on that last part. The details on it are not as fresh in my head anymore. It is definitely true that you want to minimize the amount of different components. If you need 4k and 6k resistors you're better off buying 2x2k and 3x2k instead.

New comment by waerhert in "Custom telescope mount using harmonic drives and ESP32"

waerhert — Tue, 19 Aug 2025 17:20:18 +0000

Yes! And when you need advice on an electronic circuit you can export it in netlist format from KiCAD. This is a textbased representation of the schematic which is very understandable by LLMs

New comment by waerhert in "Custom telescope mount using harmonic drives and ESP32"

waerhert — Tue, 19 Aug 2025 15:44:07 +0000

Good catch and explanation!