# uranashel blog > 27 posts on sensors, DSP, physics and shipping mobile apps. Every post has a Markdown mirror at the same path with a `.md` extension. ## [Allan variance, or how long a gyroscope can be trusted](https://uranashel.com/blog/allan-variance-gyro.html) 2026-08-25 · 21 min · physics, wheria, math We left five phones logging their gyroscopes overnight and used Allan deviation to work out how many minutes of heading Wheria can borrow between compass corrections. Markdown: https://uranashel.com/blog/allan-variance-gyro.md · JSON: https://uranashel.com/api/v1/posts/allan-variance-gyro ## [An inaudible sonar that watches you breathe](https://uranashel.com/blog/sonar-breathing-doppler.html) 2026-08-18 · 20 min · sonarish, dsp, physics Sonarish's experimental breathing monitor drives the speaker at 19 kHz, listens on the mic, and reads 118 µm of chest motion out of the phase of the echo. Markdown: https://uranashel.com/blog/sonar-breathing-doppler.md · JSON: https://uranashel.com/api/v1/posts/sonar-breathing-doppler ## [Semantic search with no server in the loop](https://uranashel.com/blog/on-device-embeddings.html) 2026-08-11 · 19 min · stashio, math, engineering Sentence embeddings, int8 vectors and a brute-force cosine scan let Stashio search your saved links by meaning entirely on the phone. Markdown: https://uranashel.com/blog/on-device-embeddings.md · JSON: https://uranashel.com/api/v1/posts/on-device-embeddings ## [The lab behind the Lab page](https://uranashel.com/blog/lab-behind-the-lab.html) 2026-08-04 · 18 min · engineering, dsp A tech-stack tour of the browser demos on the lab page, from AnalyserNode fine print to hand-shifted spectrogram pixels, built with no framework and no trackers. Markdown: https://uranashel.com/blog/lab-behind-the-lab.md · JSON: https://uranashel.com/api/v1/posts/lab-behind-the-lab ## [The battery budget of an always-on sensor app](https://uranashel.com/blog/battery-budget-sensors.html) 2026-07-27 · 19 min · engineering, wheria, physics Four phones on a shelf, airplane mode, screen off, and five weeks of overnight battery logs to find out what each sensor really costs an always-on app. Markdown: https://uranashel.com/blog/battery-budget-sensors.md · JSON: https://uranashel.com/api/v1/posts/battery-budget-sensors ## [Shipping the same day on two app stores](https://uranashel.com/blog/shipping-two-stores.html) 2026-07-18 · 18 min · engineering, studio atuan explains the release train that moves five apps to two stores on the same day, with review-time numbers from the studio's own log. Markdown: https://uranashel.com/blog/shipping-two-stores.md · JSON: https://uranashel.com/api/v1/posts/shipping-two-stores ## [Welcome to uranashel](https://uranashel.com/blog/welcome-uranashel.html) 2026-07-04 · 20 min · studio Who we are, why five apps exist, and how this blog explains the physics behind them — in plain language. Markdown: https://uranashel.com/blog/welcome-uranashel.md · JSON: https://uranashel.com/api/v1/posts/welcome-uranashel ## [Why everything runs on your phone](https://uranashel.com/blog/on-device-first.html) 2026-06-15 · 19 min · privacy Why parking, sleep audio, and noise meters must compute on your phone — latency, privacy, and offline garages explained step by step. Markdown: https://uranashel.com/blog/on-device-first.md · JSON: https://uranashel.com/api/v1/posts/on-device-first ## [Indoor navigation when GPS dies](https://uranashel.com/blog/building-wheria-indoor.html) 2026-05-28 · 21 min · wheria, physics When GPS fails underground, Wheria walks you back with steps, heading, and pressure — how sensor fusion works and what we honestly tell users. Markdown: https://uranashel.com/blog/building-wheria-indoor.md · JSON: https://uranashel.com/api/v1/posts/building-wheria-indoor ## [Sound that never repeats](https://uranashel.com/blog/estua-non-repeating-audio.html) 2026-04-10 · 20 min · estua, dsp Your brain detects loops; Estua generates fresh ambient sound every night. How real-time synthesis at 48 kHz replaces repeating rain clips. Markdown: https://uranashel.com/blog/estua-non-repeating-audio.md · JSON: https://uranashel.com/api/v1/posts/estua-non-repeating-audio ## [Designing in strict monochrome](https://uranashel.com/blog/monochrome-ui.html) 2026-03-22 · 18 min · design Why instrument apps stay black and white, and how we fight SwiftUI blue and Material purple without sacrificing readability. Markdown: https://uranashel.com/blog/monochrome-ui.md · JSON: https://uranashel.com/api/v1/posts/monochrome-ui ## [Barometers and parking floor math](https://uranashel.com/blog/barometer-parking-math.html) 2026-03-08 · 19 min · wheria, physics Pressure changes as you descend — the hydrostatic idea behind guessing B2 vs B3, and why weather and elevators complicate it. Markdown: https://uranashel.com/blog/barometer-parking-math.md · JSON: https://uranashel.com/api/v1/posts/barometer-parking-math ## [Magnetometers and compass nightmares](https://uranashel.com/blog/compass-calibration-story.html) 2026-02-18 · 22 min · wheria, physics Magnetometers in steel garages see a distorted Earth field. How Wheria calibrates, when it trusts the gyro instead, and why we warn instead of guessing. Markdown: https://uranashel.com/blog/compass-calibration-story.md · JSON: https://uranashel.com/api/v1/posts/compass-calibration-story ## [Step detection and IMU odometry](https://uranashel.com/blog/step-detection-imu.html) 2026-02-04 · 20 min · wheria, physics Double integration drifts fast; counting steps does not. A clear explanation of pedestrian dead reckoning in Wheria. Markdown: https://uranashel.com/blog/step-detection-imu.md · JSON: https://uranashel.com/api/v1/posts/step-detection-imu ## [Kalman filters for parking](https://uranashel.com/blog/kalman-filter-parking.html) 2026-01-21 · 21 min · wheria, math Combining noisy steps, heading, and pressure without panic — an intuitive tour of the filter Wheria uses underground. Markdown: https://uranashel.com/blog/kalman-filter-parking.md · JSON: https://uranashel.com/api/v1/posts/kalman-filter-parking ## [FFT for mortals](https://uranashel.com/blog/fft-made-readable.html) 2026-01-07 · 19 min · sonarish, dsp What a spectrum actually shows, how Sonarish builds it from microphone data, and how to read peaks from fans and motors. Markdown: https://uranashel.com/blog/fft-made-readable.md · JSON: https://uranashel.com/api/v1/posts/fft-made-readable ## [A-weighting and decibels explained](https://uranashel.com/blog/a-weighting-decibels.html) 2025-12-14 · 18 min · sonarish, physics Decibels, A-weighting, and LAeq explained so your phone measurements mean something next to real-world noise limits. Markdown: https://uranashel.com/blog/a-weighting-decibels.md · JSON: https://uranashel.com/api/v1/posts/a-weighting-decibels ## [Machine fault diagnosis via acoustic baseline](https://uranashel.com/blog/machine-fault-baseline.html) 2025-11-28 · 20 min · sonarish Machines hum in patterns; Sonarish lets you save a healthy baseline and compare later — acoustic diagnosis without cloud AI. Markdown: https://uranashel.com/blog/machine-fault-baseline.md · JSON: https://uranashel.com/api/v1/posts/machine-fault-baseline ## [Sleep, waves, and why your brain likes surf](https://uranashel.com/blog/estua-sleep-and-waves.html) 2025-11-10 · 18 min · estua, physics Why surf-like 1/f noise soothes sleep, and how Estua mimics it with slow modulation instead of a beach recording on repeat. Markdown: https://uranashel.com/blog/estua-sleep-and-waves.md · JSON: https://uranashel.com/api/v1/posts/estua-sleep-and-waves ## [Phyzix — 100+ physics instruments in your pocket](https://uranashel.com/blog/phyzix-pocket-lab.html) 2025-10-22 · 22 min · phyzix, education Turn the phone into a physics lab: live sensors, graphs in SI units, simulations, and bilingual classroom use. Markdown: https://uranashel.com/blog/phyzix-pocket-lab.md · JSON: https://uranashel.com/api/v1/posts/phyzix-pocket-lab ## [Sensor hacking 101](https://uranashel.com/blog/phyzix-sensor-hacking.html) 2025-10-08 · 20 min · phyzix, physics Accelerometers measure specific force, not “zero when still.” A gentle primer on what each phone sensor really reports. Markdown: https://uranashel.com/blog/phyzix-sensor-hacking.md · JSON: https://uranashel.com/api/v1/posts/phyzix-sensor-hacking ## [Shipping iOS and Android at the same time](https://uranashel.com/blog/cross-platform-two-codebases.html) 2025-09-20 · 19 min · engineering SwiftUI and Compose, two codebases, one physics core — why we ship iOS and Android together and how we keep them aligned. Markdown: https://uranashel.com/blog/cross-platform-two-codebases.md · JSON: https://uranashel.com/api/v1/posts/cross-platform-two-codebases ## [Why GPS lies to you](https://uranashel.com/blog/why-gps-lies.html) 2025-09-05 · 20 min · wheria, physics Line of sight, multipath, and concrete — a physics-first explanation of why your map dot lies in parking garages. Markdown: https://uranashel.com/blog/why-gps-lies.md · JSON: https://uranashel.com/api/v1/posts/why-gps-lies ## [Nunito on every pixel](https://uranashel.com/blog/nunito-on-every-pixel.html) 2025-08-18 · 18 min · design Typography is part of measurement UI. How Nunito stays consistent across SwiftUI and Compose, and what the OS still controls. Markdown: https://uranashel.com/blog/nunito-on-every-pixel.md · JSON: https://uranashel.com/api/v1/posts/nunito-on-every-pixel ## [Life on the audio thread](https://uranashel.com/blog/dsp-audio-thread.html) 2025-08-02 · 21 min · estua, dsp Real-time audio has hard deadlines. The rules Estua follows so sleep sounds never click at 3 AM. Markdown: https://uranashel.com/blog/dsp-audio-thread.md · JSON: https://uranashel.com/api/v1/posts/dsp-audio-thread ## [Stashio — saving the internet without losing your mind](https://uranashel.com/blog/stashio-second-brain.html) 2025-07-15 · 19 min · stashio Save links and PDFs from the share sheet, find them later — Stashio’s capture and search flow, including when cloud helps. Markdown: https://uranashel.com/blog/stashio-second-brain.md · JSON: https://uranashel.com/api/v1/posts/stashio-second-brain ## [CS + Physics → app studio](https://uranashel.com/blog/physics-degree-apps.html) 2025-06-28 · 22 min · studio, physics Computer science plus physics shaped uranashel — not as credentials, but as a way to ask what sensors mean before writing code. Markdown: https://uranashel.com/blog/physics-degree-apps.md · JSON: https://uranashel.com/api/v1/posts/physics-degree-apps --- uranashel · [Home](https://uranashel.com/) · [Apps](https://uranashel.com/apps.html) · [Lab](https://uranashel.com/lab.html) · [About](https://uranashel.com/about.html) · [Blog](https://uranashel.com/blog/) · [Developers](https://uranashel.com/developers/) · [API docs](https://uranashel.com/docs/) · [Privacy](https://uranashel.com/privacy.html) Machine-readable: [llms.txt](https://uranashel.com/llms.txt) · [sitemap.xml](https://uranashel.com/sitemap.xml) · [openapi.json](https://uranashel.com/openapi.json) · [API](https://uranashel.com/api/v1/)