DeskHop – Fast Desktop Switching

Original Article ↗ Hacker News Discussion ↗

A hardware project called DeskHop shows how a pair of Raspberry Pi Pico boards can turn a standard mouse and keyboard into an ultra-fast, edge-triggered switch between two computers without any software or network connection. Commenters compare it with software tools like Synergy, Barrier, and Mouse Without Borders, noting recurring problems with Wayland support, clipboard syncing, security, VPNs, and lag, and expressing strong interest in a reliable, local-only solution. The thread also highlights how poorly served KVM/KM users feel by current commercial hardware, especially for multi-monitor, Thunderbolt, and mixed-OS setups, and speculates about open-source and commercial paths for making devices like DeskHop more widely available.

Overall reaction

  • Many commenters are enthusiastic; several call it one of the coolest hardware hacks they’ve seen recently.
  • Strong appreciation for a hardware-only, network-free solution that “just works” across OSes, including locked-down work machines.
  • Multiple people explicitly say they’d buy a pre-assembled version; some say “shut up and take my money”.

Hardware approach & behavior

  • DeskHop uses two RP2040-based boards acting as USB HID host/device, with galvanic isolation between machines.
  • It keeps keyboard/mouse enumerated on both computers and redirects input rather than reconnecting devices, avoiding USB re-detection delays.
  • Mouse “roaming” across machines is implemented via absolute HID mouse reports, while tracking relative movement internally.
  • Edge detection is done purely in the device: it accumulates coordinates and decides when the cursor has hit an edge, then switches output.

Comparisons: software KM solutions

  • Synergy and its forks (Barrier, Input Leap) are widely discussed:
    • Praised for cross-platform support, clipboard sharing, and long-term use.
    • Criticized for instability, configuration pain, bugs, and poor Wayland support.
    • Concerns about Synergy’s paywalled TLS and Electron-based UI.
  • Other software mentioned: Mouse Without Borders (Windows), lan-mouse, x2x, ShareMouse, RKVM (buggy for some), VNC/RDP as alternatives.
  • Some prefer software for clipboard/file sharing; others prefer hardware for login screens, security, and air-gapped setups.

Comparisons: KVMs, monitors, and docks

  • Many complain existing KVMs are expensive, flaky, slow to switch, or have HDMI/EDID issues.
  • DisplayPort-based KVMs (especially from specialist vendors) are seen as better but pricey and cable-quality-sensitive.
  • Several monitors (Dell, BenQ, Gigabyte, Dell 6K, etc.) with built-in KVMs or USB hubs plus DDC/CI scripting are highlighted as strong alternatives.
  • Users want “one button” or mouse-edge switching for full KVM (monitor + USB), which DeskHop currently does not provide.

Technical notes & limitations

  • Absolute mouse mode works across different resolutions because the host maps logical min/max to its own screen.
  • Gaming and cursor-capture scenarios (FPS locking cursor to center) may conflict with absolute-mode roaming; a relative/“hold key to cross” mode is requested.
  • Current design requires both computers powered; otherwise switching behavior is unclear or undesirable for some.
  • Questions raised about extending to 3+ machines, Bluetooth devices, Chromebooks, Android/iOS, and touch/precision gestures.

Commercialization & DIY

  • Some argue it should stay a niche/open project; others advocate Kickstarter or small-scale manufacturing.
  • Existing commercial “roaming/borderless KM switches” and Pi-based KVMs are noted, but are often costly or limited.
  • Several commenters share related Pico/Teensy DIY KM/KVM projects and express interest in better documentation and build tutorials.