Mandarin (aigh.tech)
v1.0.0Mandarin Chinese HSK 1-4: vocabulary, tones, sentences and dialogues
Learning
Things I am studying, as spaced-repetition decks. The cards live here as plain JSON, a small desk companion pulls them and quizzes me, and this page keeps score.
RF at 2.4 GHz
v1.1.0Transmission lines, Smith chart, S-parameters, resonators and matching (Bowick, Lau), PCB antennas (Wallace, Pandey), signal integrity (Bogatin) and VNA measurement for 2.4 GHz products
Phase 1 of 5 · RF foundations0/29
Biosignal electronics
v1.0.0Biopotential sources, electrodes, amplifiers, interference, noise and patient safety - from Webster's Medical Instrumentation and Northrop
Phase 1 of 4 · Where the signals come from (Webster ch. 4, Northrop ch. 1)0/20
EEG
v1.0.0Generators, recording technique, artifacts, the normal and abnormal record, ICU patterns, and time-frequency analysis - from Rowan's Primer, Nieder, Cohen and Buzsáki
Phase 1 of 4 · Generators and recording (Rowan ch. 1, Nieder ch. 5, Cohen ch. 5, Buzsáki cycle 4)0/20
Analog CMOS design
v1.0.0MOS device physics, single-stage and differential amplifiers, op-amp topologies, stability and compensation, biasing and bandgap references - from Razavi's Design of Analog CMOS Integrated Circuits
Phase 1 of 5 · Build the foundation (months 1–4)0/26
How it works
Every module is a manifest pointing at one or more decks of multiple-choice, true/false and flashcard questions, each with an explanation. Ids are stable, versions follow semver, so a device can keep its scheduling history across edits.
Retention is tracked per card with a Leitner schedule - a card scheduled sixteen days or more ahead counts as known. Curriculum progress is the roadmap checklist next to each module. The Mandarin trainer runs in the browser; the engineering decks are studied on the desk device or right here, with the same schedule kept in this browser.