🦎 Steam Deck Tools – Lizard Mode Bug Analysis & Proposed Solutions

I've been researching the known bug involving Lizard Mouse and Lizard Buttons on Steam Deck and wanted to share my findings and some potential solutions.

🔧 How Steam Deck Tools Works

• Steam Deck Tools (SDT) disables Lizard Buttons and emulates button presses in software.
• It keeps Lizard Mouse enabled to preserve smooth native mouse movement.
• This mismatch is the root of the issue.

🐞 Problem Description

The latest SteamOS firmware introduces a change:

When Lizard Buttons and Lizard Mouse are not enabled or disabled together, it causes erratic behavior.

In Desktop Mode:

• Mouse stutters every 250ms.
• SDT sends updates to the Neptune Device (Steam Controller) every 250ms.
• These updates disable Lizard Buttons and enable Lizard Mouse.
• This mismatch appears to cause a firmware reset, resulting in stutter.

In Xbox360 Mode:

• The same mismatch causes firmware resets and inconsistent inputs.

If both Lizard Mouse and Buttons are enabled:

• The firmware reset issue stops.
• But SDT still emulates button presses, causing double inputs.

If both are disabled:

• The reset issue also stops.
• But we lose the smooth movement of Lizard Mouse—critical for many games.

🧠 Possible Solutions

1. Do Nothing and Wait (least preferred)

• This may be a low-priority bug in SteamOS.
• Valve might fix it in a future update, but there’s no guarantee.

2. Investigate New Reports to the Firmware

• The report format to the Neptune Device may have changed.
• Reverse engineering is needed to determine the correct bytes to send.
• This requires firmware expertise—any help is welcome!

3. Refine Steam Deck Tools Emulation

• In Desktop Mode:
  • Enable both Lizard Mouse and Buttons.
  • Remove button emulation in SDT to avoid double inputs.
• In Xbox360 Mode:
  • Disable both Lizard Mouse and Buttons.
  • Improve SDT’s mouse emulation to mimic Lizard Mouse:
    • Add haptic feedback
    • Match sensitivity
    • Implement glide behavior after release

⚠️ Concerns:

• Could mouse emulation be flagged by anti-cheat systems? So far, it hasn’t.
• Might it introduce input lag? Possibly—but it’s better than nothing.

✅ Verdict

🔧 Optimal Solution:

If anyone can reverse engineer the firmware to allow Lizard Mouse enabled and Lizard Buttons disabled—we need you!
Gamers everywhere would be eternally grateful for saving Windows on Deck.

🛠️ A Nice Workaround:

I’m willing to improve SDT’s fallback trackpad mouse emulation to mimic Lizard Mouse in Xbox360 Mode.
Time permitting, I’ll work on this soon. If you’re able to contribute, please do—every bit helps!

Thanks for reading! 🙂