Alternatives
Products that do what I turned algae into a bio-altimeter and put it on a weather balloon does
Hi HN - My name is Andrew, and I'm a high school student. This is a write-up on StratoSpore, a payload I designed and launched to the stratosphere. The goal was to test if we could estimate physical altitude based on algae fluorescence (using a lightweight ML model trained on the sensor data). The blog post covers the full engineering mess/process, including: - The Hardware: Designing PCBs for the AS7263 spectral sensor and Pi Zero 2 W. -The biological altimeter: How I tried to correlate biological stress (fluorescence) with altitude. - The Communications: A custom lossy compression…
- 1BA
Hi everyone! Shortly after publishing my iOS 4 jailbreak last October[1], I got to work on my next hobby project: a from-scratch homebrew GPS receiver, which can solve the user’s location solely from billions of radio antenna samples. I took a commodity SDR (alongside the Python standard library and numpy) and built a signal processing pipeline that can detect and track GPS satellites over many minutes, drop and pick up satellites as they come in and out of view, and precisely determine the user’s position and clock inaccuracy. All told, gypsum can go from a cold start to a fix on the user’s…
2024 · axleos.com
- 2MH
Me and a few friends made this design document as part of our entry to the UK CanSat competition where a high school team is required to build a probe to be launched. The probe must serve some purpose, and ours was to map the temperature and pressure of the air at different altitudes. We had the opportunity to launch it a week ago and you can find the video of our launch here: https://drive.google.com/file/d/16bsLzxjP7OWRqVvCB62cLv7QYLR... During the launch we reached 400m above sea level, and the can pulled 70gs successfully. The parachute and can stayed intact.…
2025 · drive.google.com
- 3OA
Hey HN! I went to an ATProto meetup last week, and as a burnt-out semi-academic who hates academic publishing, I thought there might be a cool opportunity to build on Octopus (https://www.octopus.ac/), so I got a bit excited over the weekend and built Octosphere. Hopefully some of you find it interesting! Blog post here: https://andreasthinks.me/posts/octosphere/octosphere.html
Feb 2026 · octosphere.social
- 4CE
A common open source approach to observability will begin with databases and visualizations for telemetry - Grafana, Prometheus, Jaeger. But observability doesn’t begin and end here: these tools require configuration, dashboard customization, and may not actually pinpoint the data you need to mitigate system risks. Coroot was designed to solve the problem of manual, time-consuming observability analysis: it handles the full observability journey — from collecting telemetry to turning it into actionable insights. We also strongly believe that simple observability should be an innovation…
2025 · github.com
- 5
- 6RT
I ported Microsoft's TRELLIS.2 (4B parameter image-to-3D model) to run on Apple Silicon via PyTorch MPS. The original requires CUDA with flash_attn, nvdiffrast, and custom sparse convolution kernels: none of which work on Mac. I replaced the CUDA-specific ops with pure-PyTorch alternatives: a gather-scatter sparse 3D convolution, SDPA attention for sparse transformers, and a Python-based mesh extraction replacing CUDA hashmap operations. Total changes are a few hundred lines across 9 files. Generates ~400K vertex meshes from single photos in about 3.5 minutes on M4 Pro (24GB). Not as fast as…
Apr 2026 · github.com
- 7AP
We ported pbrt-v4 to Julia and built it into a Makie backend. Any Makie plot can now be rendered with physically-based path tracing. Julia compiles user-defined physics directly into GPU kernels, so anyone can extend the ray tracer with new materials and media - a black hole with gravitational lensing is ~200 lines of Julia. Runs on AMD, NVIDIA, and CPU via KernelAbstractions.jl, with Metal coming soon. Demo scenes: github.com/SimonDanisch/RayDemo
Feb 2026 · makie.org
- 8
- 9XR
2025 · github.com
- 10RT
LiveSplat is a system for turning RGBD camera streams into Gaussian splat scenes in real-time. The system works by passing all the RGBD frames into a feed forward neural net that outputs the current scene as Gaussian splats. These splats are then rendered in real-time. I've put together a demo video at the link above.
2025
- 11IV
This is a GPU "software" raytracer (i.e. using manual ray-scene intersections and not RTX) written using the WebGPU API that renders glTF scenes. It supports many materials, textures, material & normal mapping, and heavily relies on multiple importance sampling to speed up convergence.
2024 · github.com
- 12NR
This is a service I've built to provide equirectangular cloud maps of the whole Earth, updated every 3 hours, for free. It's based on infrared and visible light data from EUMETSAT, processed to enhance the clouds and try to reduce the impact of surface temperatures on the final image. I built it because it's surprisingly hard to find these kinds of images in a format that's useful to developers and hobbyists. I was building a 3D ISS tracker and wanted to include live clouds but couldn't find anything good, so I got sidetracked, and here we are.
2023 · github.com
- 13OS
2016 · openawg.github.io
- 14AH
I've been working on this for a while now, and I'm happy to share! I've been into launching weather balloons for a few years. One aspect of the hobby that really drew me in was the tracking side of things. Tracking systems let you follow the balloon's position throughout the flight and, most importantly, know exactly where it lands so you can recover the instrumentation. APRS is what I started out using during my first few years in the hobby, after I got my amateur radio license in 2020 (W0MXX). I designed a few small boards using the trackuino…
2025 · github.com
- 15IM
Hey guys, A couple weeks ago, I was in Shenzhen, China for a hackathon and on the first day, we all used the one-day PCB fabrication to make PCB badges to wear during the event. I decided to go a little crazy and make some cool 3D alchemical-cosmological badges. It's 3 PCB's stacked on-top of each other that's connected using testpoints on each board. The innerboard has a 10 cent CH32V003 MCU that powers the WS2812B neopixels on the outer rings using the testpoints and shines through using exposed soldermask. If you have any questions about how the design works, feel free to let me know!
Aug 2026 · github.com
- 16
🎈 👽 🛸 Weather balloon to the stratosphere with a Raspberry Pi - stratopi-org/stratopi
27d ago · github.com
- 17HS
I saw a tweet that tinygrad is so good that you could make a graphics library that wraps tg. So I’ve been hacking on a gtinygrad, and honestly it convinced me it could be used for legit research. The JIT + tensor model ends up being a really nice way to express light transport all in simple python, so I reimplemented some new research papers from SIGGRAPH like REstir PG and SZ and it just works. instead of complicated cpp its just a 200 LOC of python.
Jan 2026 · github.com
- 18SE
I built StellarSnap as a calm, ad-free space to explore NASA’s Astronomy Picture of the Day (APOD) and learn astronomy along the way. What it includes: - A clean APOD archive browser with a Random APOD button - A growing Glossary with term highlighting across the site - A 2D Orbit Simulator where you can test satellite motion with real physics - A deeper Encyclopedia, still early, but expanding - Subtle touches like “see past APODs using this term” - And more to come It’s entirely ad-free, cookie-free, and not affiliated with NASA, but I was honored to have StellarSnap mentioned on the…
2025 · stellarsnap.space
- 19SG
Submarius started as just a dashboard for diving conditions, but I quickly realized that there is simply no API for water clarity, nor even a simple way to calculate it. Divers call it viz, and it is one of the most consequential factors for a diving experience. So I dove the viz rabbit-hole. I landed on a state-augmented ensemble kalman filter. More details on the /clarity page. My question for the HN audience is if anyone knows of a better way of doing this? There is a ton of satellite data to train on, but a lot of it is messy (clouds read as turbid water, shallow reefs reflect…
Jun 2026 · submarius.com
- 20SI
We built a pocket-sized optical breath analyzer based on an optical sensor for measuring CO2 and O2. It streams CPET metrics in real time (VO2, VCO2, VE, RER, Tv etc) for breath-by-breath analysis. Functional prototype based custom PCB, mobile app, and web platform are working. Demo videos: https://youtu.be/-DcvRPJJkj0 https://youtube.com/shorts/Ycy8wP4oW2o?si=W0n1Oyof7M37kdta What’s different Instead of electrochemical O₂ fuel cells and typical CO₂ NDIR modules (slower response, periodic replacement/calibration), we use non-consumable optical sensors…
Oct 2025 · mera.fit
- 21IB
You know that old TI calculator you used in high school, then put in a box and forgot about? Have you ever wished you had an operating system for your calculator with preemptive multitasking, dynamic memory management, a tree filesystem conforming to the FHS, and all the comforts of Unix? Well, good news: that's totally a thing that exists. I've been working on my kernel for about three and a half years now and I'm looking for new contributors to help out. It's written entirely in z80 assembly, and it's both challenging and fun to work on. There's an IRC channel for contributors or people…
2014
- 22MA
Yes, the urine tank on the International Space Station. In real time, I might add! This uses the official live telemetry stream from Lightstreamer, although – at least at the moment – it doesn't eg. check what the signal status is so telemetry might be down altogether and you'd never know. Maybe in v0.2. Native menu bar application, so it doesn't require running a copy of Chromium and Node to show you two emojis and a percentage. I got the idea for this when somebody linked to https://iss-mimic.github.io/Mimic/ joking about how we can see in real time how full the urine…
2024 · github.com
- 23AC
Hi HN!, We're a group of High Schooler's who have made a website for an international cryptic hunt we have been organizing. Everything has been built from the ground up and has been open sourced. We'd love feedback on our work. And if it interests you, feel free to register and try a level or two! URL: https://halocrypt.com/ Source: https://github.com/halocrypt We're particularly proud of our frontend, since we have used a framework we built ourselves!
2021
- 24WP
This was my recent weekend project, aimed at teaching me JavaScript, a bit of HTML5, and (mostly) WebGL. The orbital data are from NASA JPL. I was inspired in part by this Flash app: http://www.dynamicdiagrams.com/wp-content/uploads/2011/04/orrery_2011_bce.swf, but wanted to do something in 3D. Coming from the games-dev world, this is my first introduction to web coding. The UI is jquery. I mostly used http://learningwebgl.com/blog for the 3D stuff. Being WebGL, it will work mostly on Chrome, Firefox 4 Beta. Forget about IE. I needed to figure out how to render text to the WebGL canvas - I…
2011 · solar-system-explorer.com
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