dscap

A small, headless command-line tool that drives a DreamSourceLab DSCope oscilloscope or DSLogic logic analyzer without the DSView GUI. It links the vendor's own libsigrok4DSL — the same library DSView runs — so it sees the exact per-device capabilities the GUI does.

It is built for scripts and agents: every run prints one JSON object to stdout, and a capture also writes a native .dsl file (a plain zip in DreamSourceLab's layout, directly openable in DSView) with that same JSON embedded inside it.

./dscap enumerate          # identify the attached device  -> JSON
./dscap capture.ini        # run the measurement in the INI -> JSON + .dsl

Helper scripts under scripts/ round it out: autorange.py picks each channel's vdiv/offset automatically (short range-find captures, then one long capture — no hand-tuning), and dsl2png.py / dsl2npy.py turn a .dsl into a plot or a NumPy array.

See AGENTS.md for the full output contract and config format, and capture.ini.example for a sample config.

Status

All capture modes are bench-verified on hardware — the DSO modes on a DSCope U3P100, the logic modes on a DSLogic Plus:

• mode=single — instant one-shot, shallow and deep (≤128 Mi/ch, 512 MiB/ch OOM guard)
• mode=roll — continuous best-effort capture for duration_s (capture_ratio honesty when the host can't keep up)
• mode=stream — DSCope ANALOG ≤10 MHz continuous DAQ
• mode=logic / logic-stream — DSLogic digital capture (Buffer and Stream)

Calibration (codes → mV), the JSON summary and its embedded copy, the native .dsl writer, runtime config validation (reject, not clamp), and per-channel clipping flags (REF_MIN/REF_MAX) all match DSView and open in it.

Still on the bench list: LOGIC real-signal fidelity (verified channel↔index mapping against a known wired signal), SR_DF_OVERFLOW provocation, and cold-device config reset. Only the DSCope U3P100 and DSLogic Plus have been tested — other models should work (all boundaries are queried at runtime, not hardcoded) but are untested.

When to use this — and when not to

This tool is deliberately narrow. There is real prior art, and for some jobs you should use it instead:

• mainline sigrok / sigrok-cli — the upstream dreamsourcelab-dslogic driver. Mature and packaged, but it is logic-analyzer only (no DSCope analog / DSO), the newer models (U3Pro16/32, …) are unsupported, and it writes sigrok's .sr session format, not a DSView-openable .dsl. Use it if you have a supported DSLogic and want the standard sigrok toolchain.

• scopehal-sigrok-bridge — like this tool, it links libsigrok4DSL headlessly, so it does reach DSCope analog and the newer hardware. But it is a SCPI + binary socket bridge that feeds the ngscopeclient GUI for live viewing; it is not a file-writing CLI (no .dsl, no JSON, no one-shot-to-disk). Use it if you want to watch a DSCope live in ngscopeclient.

Use dscap when you want a single binary that takes one headless, config-driven DSO capture on current DSCope hardware and leaves you a JSON summary plus a GUI-openable .dsl file — i.e. for automation, agents, and reproducible bench captures, not interactive scoping.

Build

libsigrok4DSL is built from the pinned DSView submodule, so fetch it first:

git submodule update --init        # third_party/DSView at the pinned commit

Then build with either Make or CMake:

make                               # -> ./dscap
# or
cmake -S . -B build && cmake --build build -j   # -> ./build/dscap

Requires the glib-2.0, libusb-1.0, and zlib development packages (plus a C compiler and CMake/Make). Nothing prebuilt is relied on — the libsigrok4DSL subset is compiled from the submodule sources.

At runtime the device needs its FX2/FPGA firmware, which DSView ships under its resource directory. dscap locates it via, in order: the [capture] res_dir config key, the DSVIEW_RES_DIR environment variable, then a per-OS compiled default (/opt/dsview/share/DSView/res on Linux, C:\Program Files\DSView\res on Windows — next to DSView.exe). The path used is logged to stderr at startup.

Close the DSView GUI first — only one process may own the device at a time. After a run the device stays warm; power-cycle / re-plug between captures (the tool detects the warm fallback and exits with a clear error).

License

dscap is © 2026 Martin Kupec, licensed under the GPLv3 or later (it links the GPLv3+ libsigrok4DSL). It does not include or redistribute any DreamSourceLab firmware or FPGA bitstream — those ship with DSView and remain under DreamSourceLab's own terms.

DSView and libsigrok4DSL are © DreamSourceLab; sigrok and sigrok-cli are © the sigrok project; scopehal-sigrok-bridge is © its authors. This is an independent tool, not affiliated with or endorsed by any of them.