PentaGrammata

A cross-platform Morse code copying practice application built with .NET 10 and Avalonia UI.

PentaGrammata plays random five-character groups as Morse code audio and lets you type what you hear. After each session it scores your accuracy using Levenshtein distance and shows a side-by-side diff of sent vs. received groups.

Features

• Generates random 5-character groups from configurable character sets (letters, digits, punctuation, prosigns)
• Plays groups as synthesized Morse code audio using the Farnsworth timing method (separate character WPM and average WPM)
• Timed practice sessions with a live countdown
• Accuracy scoring with per-group diff output and a configurable error-rate threshold
• Fully configurable: tone frequency, volume, sample rate, WPM, session duration, and character set
• Settings are persisted across sessions
• Cross-platform: Windows, Linux (x64/arm64), and macOS

Configuration and results

• Windows: %AppData%\PentaGrammata and %LocalAppData%\PentaGrammata are both searched; %LocalAppData%\PentaGrammata is used for writing.
• Linux: $XDG_CONFIG_HOME/PentaGrammata or $HOME/.config/PentaGrammata.
• macOS: audio playback is not yet fully implemented (placeholder only).

Requirements

• .NET 10 SDK

Building the Windows installer

• NSIS (Nullsoft Scriptable Install System)

Building the Linux packages

• dpkg-deb (Debian/Ubuntu) — for .deb packages
• rpmbuild (Fedora/RHEL) — for .rpm packages

Building

dotnet build src/PentaGrammata.csproj

Running tests

dotnet test tests/PentaGrammata.Tests/PentaGrammata.Tests.csproj

Packaging

Windows installer (NSIS)

.\scripts\Build-Installer.ps1
# or with an explicit version
.\scripts\Build-Installer.ps1 -Version "1.1.0"

Debian package

./scripts/Build-Deb-Installer.sh
# or for arm64
./scripts/Build-Deb-Installer.sh --runtime linux-arm64

RPM package

./scripts/Build-Rpm-Installer.sh
# or with an explicit version and release number
./scripts/Build-Rpm-Installer.sh --version 1.1.0.0 --release 2

All packaging scripts read the version from version.txt by default and accept a --version / -Version flag to override it.

Configuration

appsettings.json in the application directory controls all defaults:

Section	Key	Default	Description
Audio	SampleRate	44100	Audio sample rate (Hz)
Audio	Frequency	523.25	Tone frequency (Hz)
Audio	Volume	0.7	Volume (0–1)
Audio	BeepRampMs	4	Envelope ramp time (ms)
Practice	DefaultDurationMins	1	Session length (minutes)
Practice	CharacterWpm	18	Character speed (WPM)
Practice	AverageWpm	18	Average (Farnsworth) speed (WPM)
Practice	DefaultCharacterSet	Default	Character set used on startup
Practice	ErrorThreshold	5.0	Maximum error rate (%) to pass
CharacterSets	(named sets)	see below	Named sets selectable in the UI

Default character sets:

Name	Contents
Default	A–Z, 0–9, /+?=
Letters	A–Z
Digits	0–9
Punctuation	/+?=
Full	A–Z, 0–9, /+?=, prosigns <ar><as><bk><bt><kn><sk>
Koch-LCWO-01-KM	K, M
Koch-LCWO-02-U	K, M, U
Koch-LCWO-03-R	K, M, U, R
Koch-LCWO-04-E	K, M, U, R, E
Koch-LCWO-05-S	K, M, U, R, E, S
Koch-LCWO-06-N	K, M, U, R, E, S, N
Koch-LCWO-07-A	K, M, U, R, E, S, N, A
Koch-LCWO-08-P	K, M, U, R, E, S, N, A, P
Koch-LCWO-09-T	K, M, U, R, E, S, N, A, P, T
Koch-LCWO-10-L	K, M, U, R, E, S, N, A, P, T, L
Koch-LCWO-11-W	K, M, U, R, E, S, N, A, P, T, L, W
Koch-LCWO-12-I	K, M, U, R, E, S, N, A, P, T, L, W, I
Koch-LCWO-14-J	K, M, U, R, E, S, N, A, P, T, L, W, I, J
Koch-LCWO-15-Z	K, M, U, R, E, S, N, A, P, T, L, W, I, J, Z
Koch-LCWO-16-=	K, M, U, R, E, S, N, A, P, T, L, W, I, J, Z, =
Koch-LCWO-17-F	…+ F
Koch-LCWO-18-O	…+ O
Koch-LCWO-19-Y	…+ Y
Koch-LCWO-20-+	…+ +
Koch-LCWO-21-V	…+ V
Koch-LCWO-22-G	…+ G
Koch-LCWO-23-5	…+ 5
Koch-LCWO-24-/	…+ /
Koch-LCWO-25-Q	…+ Q
Koch-LCWO-26-9	…+ 9
Koch-LCWO-27-2	…+ 2
Koch-LCWO-28-H	…+ H
Koch-LCWO-29-3	…+ 3
Koch-LCWO-30-8	…+ 8
Koch-LCWO-31-B	…+ B
Koch-LCWO-32-?	…+ ?
Koch-LCWO-33-4	…+ 4
Koch-LCWO-34-7	…+ 7
Koch-LCWO-35-C	…+ C
Koch-LCWO-36-1	…+ 1
Koch-LCWO-37-D	…+ D
Koch-LCWO-38-6	…+ 6
Koch-LCWO-39-0	…+ 0
Koch-LCWO-40-X	…+ X (full LCWO set)

The Koch-LCWO sets follow the LCWO character introduction order. Each set is cumulative and weighted — it contains all characters from the previous sets plus the newly introduced one, with the new character repeated several times so it appears more frequently during practice.

Lesson 13 (.) is intentionally omitted because that character was deemed not useful for practice.

All settings are editable at runtime through the in-app Settings dialog.

Project structure

src/                  Application source
  Configuration/      Configuration model classes
  Interfaces/         Service abstractions
  Models/             Data transfer objects
  Services/           Business logic (Morse generation, playback, scoring)
  ViewModels/         MVVM view models (CommunityToolkit.Mvvm)
  Views/              Avalonia XAML views
tests/
  PentaGrammata.Tests/  MSTest unit tests (NSubstitute for mocking)
scripts/              Build and packaging scripts
installer/nsis/       NSIS installer script

License

See LICENSE.