sp410-opensource-windows

An open-source Windows driver for the iDPRT SP410 4-inch direct-thermal label printer (and the SP410BT / SP420), with an installer built entirely from open-source tools.

It is the Windows sibling of sp410-cups-driver and uses the same clean-room conversion code. That code has been confirmed on a real SP410 under Linux, and it produces byte-identical TSPL output here. No vendor code, binaries or installers were used or consulted.

Status: 1.0.0, confirmed on hardware. Printing to a physical SP410 over USB from Windows 11 works through the installer, the service and Windows' own IPP Class Driver. CI also installs, prints and uninstalls on a real Windows machine for every commit.

How it works

Windows no longer wants new third-party printer drivers: since January 2026 Microsoft has stopped publishing new v3/v4 drivers through Windows Update and steers printers to its in-box IPP Class Driver. So instead of a signed kernel- or user-mode print driver, this project ships a small service that is an IPP Everywhere printer, and lets Windows' own driver print to it:

 Word / browser / shipping app
        │  GDI / XPS
        ▼
 Microsoft IPP Class Driver  (built into Windows, already signed)
        │  PWG Raster pages, 203 dpi, label sizes we advertise
        ▼  HTTP POST http://127.0.0.1:8631/ipp/print
 sp410-ippd.exe  (Windows service "SP410 Open Driver")
        ├─ PWG raster reader (own implementation, no libcups)
        ├─ halftoning, clipping, shift   ┐ same code as the Linux driver
        └─ banded TSPL BITMAP writer     ┘
        │  TSPL
        ▼  usbprint.sys (in-box "USB Printing Support"), or COM / TCP
 iDPRT SP410

Nothing is installed in the kernel or the print spooler, so there is no driver signing, no test mode, and it keeps working with Windows Protected Print Mode. Details and the alternatives considered: docs/ARCHITECTURE.md.

Install

1. Plug in the SP410 by USB and switch it on.
2. Download sp410-opensource-windows-<version>-setup.exe from Releases. Optionally check it against SHA256SUMS.txt there (Get-FileHash <file> in PowerShell).
3. Run it and accept the Windows administrator prompt. Windows SmartScreen may warn because the installer is not code-signed; choose More info → Run anyway (see docs/INSTALL.md).
4. Print anything to iDPRT SP410. The default label size is 4 × 6 in.

Requirements: 64-bit Windows 10 or Windows 11 (Windows 11 recommended, since Microsoft's IPP support improves with each release). Windows on ARM runs the x64 build through emulation.

Silent install for fleets: setup.exe /S. Full guide, upgrading, Bluetooth and network printers: docs/INSTALL.md.

Settings

Windows' print dialog shows the label size, copies and orientation. Printer options that IPP has no standard name for (darkness, speed, gap or black-mark media, halftoning, tear-off, offsets) live in one file:

C:\ProgramData\SP410\sp410.ini (Start menu → SP410 Open Driver → Edit printer settings)

[device]
uri = usb                     ; or serial:COM5, socket://192.168.1.50:9100

[media]
default = na_index-4x6_4x6in  ; default label size in the print dialog

[print]
Darkness = 10                 ; Default or 0-15
MediaTracking = Gap           ; Gap, BlackMark or Continuous
Dither = Auto                 ; Auto, Threshold, Atkinson, FloydSteinberg, Ordered

[device], [media] and [print] apply to the next label; there is no need to restart anything. The option names and ranges are the same as in the Linux driver's PPD. The sample file lists every option.

Utilities

sp410-cli.exe (in C:\Program Files\SP410 Open Driver) talks to the printer without the service:

sp410-cli list                    :: USB printers Windows can see
sp410-cli status                  :: status 0x00: ready
sp410-cli calibrate               :: measure label + gap after loading a new roll
sp410-cli test-label --size 4x6   :: label drawn with the printer's own fonts
sp410-cli --device serial:COM5 info
sp410-cli convert page.pwg out.prn Darkness=12   :: offline conversion, for debugging

The service also has a status page at http://127.0.0.1:8631/ showing the printer state, device and recent jobs.

Build from source

Everything builds on Linux with open-source tools (GCC, MinGW-w64, NSIS):

sudo apt install build-essential gcc-mingw-w64-x86-64 nsis python3
make check          # native build + 21 end-to-end tests (no printer needed)
make windows        # build/windows-x86_64/sp410-ippd.exe, sp410-cli.exe
make installer      # build/sp410-opensource-windows-1.0.0-setup.exe

llvm-mingw also works (make windows with its bin/ on PATH; ARCH=aarch64 for native ARM64). CI builds, tests under AddressSanitizer and ThreadSanitizer, produces the installer, then installs it on a real Windows machine and prints through Windows' IPP Class Driver: .github/workflows/ci.yml.

Documentation

Document	What's in it
MANIFEST.md	Every file and where it installs
docs/ARCHITECTURE.md	Why IPP instead of a classic driver; components; threading
docs/INSTALL.md	Install, upgrade, uninstall, SmartScreen, Bluetooth, network, troubleshooting
docs/HARDWARE.md	Printer specifications used, models, test status
docs/PROTOCOL.md	The TSPL commands sent and the IPP attributes advertised
docs/REVERSE_ENGINEERING.md	Clean-room rules, sources, open questions
CONTRIBUTING.md	Hardware reports, code and test conventions

License and trademarks

Apache License 2.0, see LICENSE. iDPRT is a trademark of its owner. This project is independent and is not affiliated with, endorsed by, or supported by iDPRT, HPRT or Microsoft.