Dan Singleton
blog.singleton.io · Personal blog · on HN since 2022
Dan Singleton, a software engineer who writes about personal projects like a ray tracer in Rust, a compiler, and a wristwatch OTP setup.
What HN saysHN commenters repeatedly link his wrist-worn OTP watch post as an example of the idea, and one cites his coding agents post.
19HN people shared it
11linked it in comments
10stories submitted
1.1Kstory points
8 months agolast shared
2022people per year2026
Most-shared posts
- 1TOTP tokens on my wrist with the smartest dumb watch8 people · 641 points · first shared 2022 · 124 comments on HN
- 2Coding agents have crossed a chasm3 people · 34 points · first shared 2025 · 31 comments on HN
- 3Dreamer – why we built it2 people · 2 points · first shared 2026 · discussion on HN
- 4The joy of building a ray tracer, for fun, in Rust1 people · 350 points · first shared 2022 · 72 comments on HN
- 5I Wrote a Compiler1 people · 112 points · first shared 2025 · 71 comments on HN
- 6Picowx – An APRS Powered RPi Pico-W eInk Weather Station1 people · 4 points · first shared 2024 · discussion on HN
- 7Completion.png1 people · first shared 2024
- 82021 11 24 probabilistic spreadsheet1 people · first shared 2025
- 9Ratios.png1 people · first shared 2024
- 10Nnrccar1 people · first shared 2024
- 112018 07 05 glowforge sundial1 people · first shared 2022
- 122024 01 02 advent of code 20231 people · first shared 2024
What HN people wrote when they linked it
hy100 · 2023-07-29
No phone for a few months now. I feel fantastic and only had two issues.
1. Convincing spouse and crew to fix meeting times in advance. No more "I'll text you when I get off work". This produces a much smoother cadence to life.
2. Work RSA token. Put it on a computer next to my work machine. A more ambitious hacker could put it on a wrist watch: https://blog.singleton.io/posts/2022-10-17-otp-on-wrist/. Company really needs to get YubiKeys.
jmtulloss · 2025-08-06
https://blog.singleton.io/posts/2025-06-14-coding-agents-cross-a-chasm…
The former CTO of stripe, for one.
They show you the code they produce. Why wouldn’t you trust it after reading it?
Elfener · 2025-07-01
This post came to mind: https://blog.singleton.io/posts/2022-10-17-otp-on-wrist/
I doubt anyone wants to search a f-91w.
hippari2 · 2025-06-13
This is one of the thing that smart watches should be doing, or even better, something like https://blog.singleton.io/posts/2022-10-17-otp-on-wrist/.
billyjmc · 2025-06-12
This is nearly what you’re looking for (well, not that close, but it’s got the right spirit):
https://blog.singleton.io/posts/2022-10-17-otp-on-wrist/
portalcell · 2025-02-05
If you liked this you might also enjoy this little toy project: https://blog.singleton.io/posts/2021-11-24-probabilistic-spreadsheet/
mrweasel · 2025-01-31
The F-91W is such a fun little watch[1] and people have done the weirdest stuff with it. There's a guide to make the mod on Youtube[3]. There's also the TOTP in a F-91W[2]
1) https://www.youtube.com/watch?v=r6REKCs4-1M
2) https://blog.singleton.io/posts/2022-10-17-otp-on-wrist/
3) https://www.youtube.com/watch?v=jLmAq0epfrI
tocs3 · 2024-01-23
Maybe also overkill but I saw this years ago and thought it was interesting.
https://blog.singleton.io/nnrccar/
https://hackaday.com/2012/01/03/nerual-networks-control-a-toy-car/
Also, I have built a couple toy robots that use "whiskers" to avoid obstacles.
neilv · 2023-01-02
Also non-sensor applications: https://blog.singleton.io/posts/2022-10-17-otp-on-wrist/
app4soft · 2022-09-18
Here is sundial generator for laser cut, which produces SVG.[0,1]
It might be easy to make a 3D model from generated SVG in Blender and export it to STL.
[0] https://blog.singleton.io/posts/2018-07-05-glowforge-sundial/
[1] https://github.com/dps/sundial
dps · 2024-01-15
>This year’s Advent of Code has been brutal (compare the stats of 2023 with that of 2022, especially day 1 part 1 vs. day 1 part 2).
I enjoyed completing AoC this year. While it was very clear that day 1 (esp. part 2) was significantly harder than previous years (I wrote about this among other things [0]), OP's claim seemed not obviously self evident when comparing _current_ 2022 stats to _current_ 2023 stats, as folks have had an additional full year to complete the 2022 puzzles.
I grabbed the 2022 stats from Jan 14th 2023 [1] and, indeed, the difference is quite stark. Graphing the part two completion stats[2] for both years, there was a relatively similar starting cohort size on day 1, but 2023 looks clearly harder than 2022 up until day 15. As OP observes, the ratio[3] of folks completing pt1 but not going on to complete pt 2 is way higher for a lot of days in 2023 and suggests the day 5, 10, 12 and especially day 22 part 2s were particularly difficult.
[0] https://blog.singleton.io/posts/2024-01-02-advent-of-code-2023/
[1] https://web.archive.org/web/20230114172513/https://adventofcode.com/20…
[2] https://blog.singleton.io/static/imgs-aoc23/completion.png
[3] https://blog.singleton.io/static/imgs-aoc23/ratios.png