| A2DP |
Advanced Audio Distribution Profile — Bluetooth stereo audio streaming protocol. |
| ADC |
Analog-to-Digital Converter — converts the slider's voltage to a number (e.g. 0–4095). |
| API |
Application Programming Interface — how code talks to a library or service. |
| BLE |
Bluetooth Low Energy — used for wireless features on the device. |
| CC0 |
Creative Commons Zero - a public-domain dedication that allows reuse without the usual copyright restrictions. |
| CI |
Continuous Integration — automated builds (e.g. GitHub Actions compiling WASM). |
| CMake |
Cross-platform build system used to configure the WASM/Emscripten build. |
| CORS |
Cross-Origin Resource Sharing — browser rules that block loading WASM from file:// URLs. |
| CSS |
Cascading Style Sheets — used to style the emulator (LEDs, layout). |
| DOM |
Document Object Model — the browser's representation of the page (buttons, canvas). |
| dB |
Decibel - a unit for comparing loudness. 3 dB quieter is about half the power. |
| EQ |
Equalizer - a filter that makes some pitches louder or quieter. The speaker's EQ lifts the pitches the small speaker plays well. |
| dBFS |
Decibels relative to Full Scale - a loudness scale where 0 is the loudest level the microphone can measure and quieter sounds are negative numbers (for example -60 for a quiet room). |
| DNS |
Domain Name System - turns names like cyberfidget.com into network addresses. On its own WiFi network the Fidget answers every name lookup with its own address, which is how the portal's sign-in page opens by itself. |
| EDNS |
Extension Mechanisms for DNS - extra options many phones and browsers add to a name lookup. The Fidget's portal answers lookups with or without them. |
| DER |
Distinguished Encoding Rules - a compact binary layout; firmware update signatures use it before being written as base64 text. |
| DIO |
Dual input/output - a flash mode accepted in release metadata. |
| ECDSA |
Elliptic Curve Digital Signature Algorithm - the method used to sign firmware updates, so a Fidget can check that an update came from Cyber Fidget. |
| ESP32 |
Espressif's 32-bit microcontroller — the main chip on Cyber Fidget hardware. |
| FPS |
Frames Per Second — the emulator runs at 50 FPS like the real device. |
| FreeRTOS |
Free Real-Time Operating System — the RTOS layer used by ESP-IDF under the hood. |
| GPIO |
General-Purpose Input/Output — physical pins used for buttons, etc. |
| HAL |
Hardware Abstraction Layer — the layer that swaps ESP32 drivers for browser equivalents in the emulator. |
| Harmonics |
Quieter extra pitches at 2x, 3x, 4x... a note's frequency, mixed into the sound. A small speaker that cannot reproduce a low note can still play its harmonics, so the note stays recognizable but quieter. |
| Hz / kHz |
Hertz / kilohertz — vibrations per second (1 kHz = 1000 Hz); the unit of pitch. Higher is a higher note. |
| I2C |
Inter-Integrated Circuit — serial bus used for the OLED, accelerometer, and fuel gauge. |
| I2S |
Inter-IC Sound — digital audio bus used for the speaker amplifier and MEMS microphone. |
| IDE |
Integrated Development Environment — e.g. the App Builder on the website. |
| GPU |
Graphics Processing Unit — when the phone's browser exposes it, the companion transcribes speech much faster. |
| IPv4 / IPv6 |
Internet Protocol version 4 / version 6 - the two kinds of network address. IPv4 is the familiar four-number form, like 192.168.4.1; IPv6 is the newer, longer form. |
| IndexedDB |
Browser storage used to cache compiled WASM and the phone companion's one-time transcription download. |
| JS |
JavaScript. |
| JSON |
JavaScript Object Notation - a structured text format for storing data. |
| LED |
Light-Emitting Diode. |
| LiPo |
Lithium Polymer — rechargeable battery type used in Cyber Fidget (400 mAh). |
| Li-ion |
Lithium-ion — a family of rechargeable battery chemistries. |
| MCU |
Microcontroller Unit — the processor that controls an embedded device. |
| MEMS |
Micro-Electro-Mechanical Systems — miniaturized sensor technology used in the ICS-43434 microphone. |
| ms |
Millisecond - one thousandth of a second. |
| NeoPixel |
Adafruit's addressable RGB(W) LED product line; firmware uses a shim that matches its API. |
| NVS |
Non-Volatile Storage - the small settings area in the ESP32's flash that keeps saved WiFi networks, the account link, and other settings across restarts. |
| OLED |
Organic Light-Emitting Diode — the 128×64 pixel display on Cyber Fidget. |
| OTA |
Over-the-air update - firmware delivered over a network instead of a cable. On the device and website, the action is called an "update." |
| P-256 |
A standard elliptic curve (also called prime256v1); the firmware update signing key must use it. |
| PCB |
Printed Circuit Board. |
| PEM |
Privacy-Enhanced Mail - a text format for storing keys, used for the release signing key. |
| PCM |
Pulse-Code Modulation — uncompressed digital audio stored as raw samples. |
| PNG |
Portable Network Graphics - a common lossless image file format. Aseprite can export its sprite sheets as PNG images. |
| PSRAM |
Pseudo-Static RAM - extra memory on the ESP32 module, used to buffer audio while recording and to run apps sent to the Fidget (a little slower than the chip's internal memory). |
| QIO |
Quad input/output - a flash mode accepted in release metadata. |
| RC |
Release Candidate - a test version of the firmware, tagged like v1.4.0-rc1. On the device and website it is called a "test version." |
| RGBW |
Red, Green, Blue, White — four-channel LED color. |
| RS-232 |
Recommended Standard 232 — a serial communication standard. |
| SD |
Secure Digital — the micro-SD card slot. |
| SHA-256 |
Secure Hash Algorithm 256-bit - a digest used to check that downloaded bytes match the update manifest. |
| SPI |
Serial Peripheral Interface — serial bus used for the SD card. |
| SPP |
Serial Port Profile — Bluetooth serial data streaming protocol. |
| SSD1306 |
The display controller chip used in the Cyber Fidget OLED. |
| USB |
Universal Serial Bus — used for charging and serial communication via USB-C. |
| URL |
Uniform Resource Locator - an address for a web resource. |
| USB-C |
USB Type-C — the reversible connector used for charging and serial communication. |
| UVLO |
Under-voltage lockout - a protective shutdown that stops the device from draining its battery below a safe level. |
| VU |
Volume Unit — a level meter showing how loud the microphone is hearing you (used by the Voice Notes recorder). |
| WASM |
WebAssembly — binary format that runs in the browser; the emulator runs C++ apps as WASM. |
| WAV |
Waveform Audio File — uncompressed audio format; plays on nearly any phone or computer with no special software. Voice Notes recordings are saved as WAV. |
| WebAssembly |
Binary instruction format for the web; the emulator compiles C++ to WASM. |
| WebSocket |
A persistent two-way connection between a browser page and a server — the phone companion's live caption link to the device. |
| Wi-Fi |
Wireless Fidelity — used for OTA and network features. |
| Web Serial |
A browser feature that lets a web page talk to a device over a USB serial connection. Available in desktop Chromium-based browsers such as Chrome and Edge. |
| mDNS |
Multicast DNS — the local-network name service that makes cyberfidget.local resolve without any router configuration. |
| microSD |
Compact removable Secure Digital memory-card format. |