logic-notes/docs/arch-linux-logic-analyzer-session.md

Arch Linux Logic-Analyzer Session Notes

This document captures a single practical session on an Arch Linux machine used to prepare a logic-analyzer software setup for embedded debugging and for a live sharing scenario.

Short conclusion

If the goal is to get useful logic-analyzer tooling on Linux quickly, the best default is:

sudo pacman -S pulseview sigrok-cli sigrok-firmware-fx2lafw

If the goal also includes Chinese-friendly UI and Chinese-facing materials, keep DSView as a fallback rather than the primary recommendation.

Why this stack

PulseView + sigrok

This combination is the most practical default because it gives:

• a standard open-source workflow
• broad device support
• a simple command-line interface for reproducible demos
• a low-friction path for common embedded buses such as SPI, I2C, and UART

DSView

DSView is useful when Chinese support matters more than having the cleanest install story.

In this session, the reasons to keep it as a fallback were:

• the project is clearly more Chinese-friendly
• it has Chinese language resources for UI and decoder options
• it worked in the end, but required local build fixes on a modern Arch setup

What worked without hardware

The built-in sigrok demo driver was enough to validate the toolchain.

Useful checks:

sigrok-cli --scan
sigrok-cli --driver demo --show
sigrok-cli -d demo -c samplerate=1000 -C D0,D1,D2,D3 --samples 32 -O ascii
sigrok-cli -d demo -c samplerate=1000 -C D0,D1,D2,D3 --samples 32 -O bits

This is the best path when:

• no analyzer is physically available
• the session is for teaching
• the goal is to prove that the software stack is healthy before hardware arrives

Notes on DSView on modern Arch Linux

DSView 1.3.2 did run successfully in the end, but it was not a clean out-of-the-box install.

What had to be handled

1. CMake compatibility

The project uses an older CMake baseline, so configuration needed:

cmake -S . -B build -DCMAKE_BUILD_TYPE=Release -DCMAKE_INSTALL_PREFIX=$HOME/.local -DCMAKE_POLICY_VERSION_MINIMUM=3.5

2. New toolchain compatibility fixes

Two source-level fixes were needed during the build:

• include strings.h so strcasecmp() is declared
• replace usleep() with g_usleep() in the local build

3. Decoder path and language resources

The binary was installed under ~/.local, but decoder scripts and language resources also had to exist in the expected paths:

• ~/.local/share/DSView/lang
• ~/.local/share/libsigrokdecode4DSL/decoders

Without those paths, common decoders such as SPI, I2C, and UART were not loaded correctly.

4. One bundled decoder shipped broken

The sdcard_spi decoder contained a Python syntax error and needed a local one-line fix before startup logs were clean.

Recommendation for live sharing

For a live talk or workshop, do not rely on building DSView live on stage.

Better options:

• prebuild and verify it on the target machine beforehand
• ship screenshots or a recorded walkthrough instead of a live build
• use PulseView + sigrok-cli as the live demo path

Suggested structure for an embedded sharing session

Option A: safest live demo

1. Install PulseView and sigrok-cli
2. Show sigrok-cli --scan
3. Use the built-in demo driver
4. Explain where a real FX2-based analyzer would fit in

Option B: broader comparison talk

1. Start with the open-source default stack
2. Explain when DSView is attractive
3. Highlight Chinese-support tradeoffs
4. End with a full rollback procedure

Full rollback after the session

If the machine was only used to prepare the session, a full cleanup is reasonable.

Packages removed in this session:

• pulseview
• sigrok-cli
• libsigrok
• libsigrokdecode
• sigrok-firmware-fx2lafw
• boost
• auto-installed dependencies such as libftdi, libieee1284, and libserialport

Typical package removal command:

sudo pacman -Rns pulseview sigrok-cli libsigrok libsigrokdecode sigrok-firmware-fx2lafw boost

User-level files that were also removed:

• ~/.local/bin/DSView
• ~/.local/bin/dsview
• ~/.local/share/DSView
• ~/.local/share/libsigrokdecode4DSL
• ~/.local/share/applications/dsview.desktop
• ~/.config/DreamSourceLab
• temporary build and archive files under /tmp

Final recommendation

For most embedded engineers on Linux:

• recommend PulseView + sigrok-cli first
• mention DSView as a Chinese-friendly fallback
• use the built-in sigrok demo driver when no hardware is available
• always prepare a rollback path if the machine is only being used for a share or workshop