Echo

A TUI for field-testing Ethernet communications on the factory floor, built on Phosphor.

Techs work from named presets rather than retyping IP addresses. Select a preset, apply its interface config in one keystroke, ping the device, or open its web UI — all without leaving the terminal.

Designed for the ClockWork uConsole.

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Home screen

┌─ ECHO v{version} ──────────────────────────────── #{hostname} · eth0 ┐
├─ PRESETS ────────────────────┬─ INTERFACE STATUS ─────────────────┤
│ ▶ Cube20 – Line 3 Panel A   │ CURRENT                             │
│   Cube20 – Line 3 Panel B   │  IP    192.168.1.100                │
│   Switch – Cabinet 7        │  Mask  255.255.255.0                │
│   Murr Profibus Gateway     │  Mode  Static                       │
│   Cube67 – Assembly Line 1  │  Link  ● Up                         │
│   ─ 5 of 8 ─                │                                     │
│                             │ PRESET WANTS                        │
│                             │  IP    192.168.2.50  ← mismatch     │
│                             │  Mask  255.255.255.0                │
│                             │  Target 192.168.2.1:80              │
│                             │                                     │
│                             │ ⚠ IP mismatch — press [a] to apply  │
│                             │                                     │
│                             │ PING STATUS                         │
│                             │ 192.168.2.50  — not tested    [p]   │
├─ RECENT ACTIVITY ───────────────────────────────────────────────── │
│ 14:32  ✓  Applied 192.168.2.50/24 to eth0                         │
│ 13:58  ✓  Ping 192.168.2.1 — 4ms avg, 0% loss                    │
│ 13:55  →  Set eth0 to DHCP                                         │
├─────────────────────────────────────────────────────────────────── │
│ [a] Apply IP  [p] Ping  [b] Browser  │  [n] New  [e] Edit  [d] Del │  [D] DHCP  [q] Quit │
└──────────────────────────────────────────────────────────────────── ┘

The mismatch indicator updates live as the interface state changes — no manual refresh needed.

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Requirements

• Crystal 1.20.3 (see toolchain note below)
• ping (standard on most Linux systems)
• xdg-open for browser launch (xdg-utils package)
• ip from iproute2 for interface configuration

Applying a static IP or requesting a DHCP lease requires either running Echo as root or adding a sudoers rule for the specific commands:

# /etc/sudoers.d/echo
your_username ALL=(ALL) NOPASSWD: /usr/sbin/ip, /usr/sbin/dhclient

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Installation

git clone https://gitlab.com/quiet-corner-linux/echo
cd echo
shards install
shards build --release
# Copy bin/echo to somewhere on your PATH
cp bin/echo ~/.local/bin/

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Usage

echo          # Launch

Key bindings

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Presets

Presets are stored at ~/.config/echo/presets.json. Each preset captures:

• Title — a human-readable name, e.g. Cube20 – Line 3 Panel A
• Interface — the NIC to configure, e.g. eth0
• Local IP / Subnet Mask — the static config to apply
• Remote IP / Port / Scheme — the device to test against

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Toolchain note

Echo is pinned to Crystal 1.20.3 because ameba 1.6.4 (the linter) calls Crystal::Lexer#next_string_array_token which was removed in Crystal 1.21. Once ameba ships a compatible release this pin will be removed. If you see Ameba compile errors, confirm your local Crystal version with crystal --version.

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Development

just check    # format + lint + specs
just ci       # full CI run
just run      # build and run

Echo is also Phosphor's Phase 28 "build a real app" stress test. Friction encountered while building Echo feeds back into Phosphor's issue tracker — see CLAUDE.md for how to file it.