Interrupt Scope

A device monitor with separate lanes for timer, keyboard, mouse, UART and RTC activity. Independent scales keep high-frequency timer traffic from obscuring the other devices.

Run it

Build the examples with devenv shell -- lcom-ng-build, then run:

lcom-ng run -- build/examples/interrupt_scope

Try a complete workflow

Move the pointer, type and toggle UART loopback to create observable events. Freeze the graph to inspect a window, and compare the decoded telemetry and raw-byte history.

Controls

• Space: freeze or resume the graph. L: UART loopback.
• F1: help. C clears counters and history.

Command shortcuts work on macOS; Ctrl shortcuts work on other hosts. Esc closes help first. Cmd/Ctrl+W closes the app.

In the app

These are actual runtime captures. Open a screenshot for a larger view; use Left and Right to browse, and Escape to close.

Every device has its own laneIndependently scaled lanes reveal input bursts alongside the steady timer.

Keyboard scan codesTyping produces real make and break bytes in the device inspector.

Mouse packetsThe inspector shows the three bytes of each PS/2 mouse packet.

Pause the historySpace freezes the graph while hardware counters continue to update.

Disable the serial probeL toggles COM1 loopback while the remaining devices stay live.

Start a fresh measurementC clears the counters and history, ready for the next experiment.

Learn the instrumentF1 explains rate windows, polling and loopback.

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Every device has its own lane · Independently scaled lanes reveal input bursts alongside the steady timer.

What it demonstrates

IRQ coalescing, event rates, PS/2 parsing, UART loopback, RTC polling and bounded history buffers.

Freeze holds the plotted history. Live counters are identified separately so the interface does not imply that devices have stopped.

Source: examples/interrupt_scope.c.

Refresh these screenshots

devenv shell -- python3 scripts/capture_gallery.py --app interrupt-scope

See the screenshot workflow to add states or check freshness.