SITL Forge - FPV Laboratory news & patch notes

This update adds a new, much lower-latency way to connect SITL Forge to **iNAV SITL**, plus real-time physics improvements that benefit every flight mode. ## ✨ New: iNAV RealFlight transport (recommended) SITL Forge now speaks iNAV's native **RealFlight** interface (`--sim=rf`). Instead of streaming sensors over MSP and polling for motor outputs, iNAV runs **in lockstep** with the simulator — it advances one step per exchange and pushes its motors to us directly. What that means for you: **heavy quads finally fly on a normal PID tune.** The old MSP path forced a near-zero I-term or the craft would oscillate; the RealFlight bridge removes that latency, so your 10" / 13" builds hold attitude the way they should. - Lockstep, low-latency control loop - iNAV pushes motors directly — no polling round-trip - GPS / nav modes (POSHOLD, RTH, waypoints) driven by your simulated position - Now the **default** transport — MSP HITL remains available as a fallback Setup takes a few extra launch flags on iNAV's side — the in-app **Help** panel on the iNAV card walks you through both modes step by step. ## ⚙️ Real-time physics fix (all modes) Physics now holds a true real-time 1000 Hz even when the frame rate dips, instead of slipping into slow motion. This tightens the control loop for **Betaflight, iNAV, and the built-in SIM controller** alike. ## 🛠️Other improvements - **iNAV MSP mode:** smoother attitude feed to the flight controller — less frozen-pose wobble even on the legacy transport. - **Tuning window:** the "applied" message now matches the tab you're on (Vibration, Sensors, Camera…) instead of always reading "PID/Rates sent to firmware." - **Docs:** the iNAV setup guide has been rewritten to cover both transports, GPS setup, and troubleshooting. Happy flying — feedback welcome!

The Betaflight and iNAV setup guides — the ones behind the Setup help link on each External FC card — were English-only, and stayed English even after you switched the app language. Both are now fully translated into Ukrainian and Simplified Chinese. They follow the app language. Change it in Settings → General and an open guide re-renders in place. No restart. Translated in full, not just the headings: - The troubleshooting tables - The remote-SITL and WSL2 networking sections - The Betaflight motor-order and SITL-bridge notes Commands, file paths, build targets and CLI settings are left exactly as you have to type them — only the prose around them is translated.

Betaflight changed the order of the motor values its SITL sends on the wire in April 2026. If you built your SITL from recent Betaflight source, the simulator was reading each motor's command one position off — the quad flipped the instant it left the ground. SITL Forge now asks the flight controller which generation it is, over MSP, as soon as it connects. You don't have to configure anything: old and new Betaflight builds both just work. What's new - Motor order setting in the Network window for Betaflight, defaulting to Auto. It shows what the firmware identified itself as, so you can see what Auto picked. - Manual Legacy (Betaflight 4.6 and older) and Current (builds from 24 April 2026 on) if you ever need to override it. - A warning when your SITL was built for the Gazebo bridge — that build reports its attitude rotated 90°, and no motor setting can fix it. Rebuild with make SITL_X_PLANE. - The Betaflight setup guide now leads with the right build command. If you build Betaflight SITL yourself: use make SITL_X_PLANE rather than a bare make TARGET=SITL. Current Betaflight master defaults the plain target to the Gazebo bridge, which speaks a protocol the simulator can't fly with. Requires the Betaflight DLC. Update both the game and the DLC.

You can now point SITL Forge at a SITL running somewhere other than your own PC — inside WSL on Windows, or on another computer on your network.

What's new

• Network settings per flight controller. Open the External FC menu and click Network on any integration card to set the SITL host and every port it uses.
• Test connection button — check the address is right before you activate.
• Hostnames work, not just IP addresses.
• Settings are remembered between sessions, per flight controller.

Betaflight

Betaflight sends its motor output to a single address it is given at launch, so a remote setup needs one extra step: start the SITL pointing back at the machine running SITL Forge. betaflight_SITL.elf --ip 192.168.1.50 (On Betaflight 4.5.x, pass the address as the first argument instead.)

iNAV

Nothing to configure on the iNAV side — set the host in the Network window and you're done.

Using WSL?

The Setup help panel on each integration card now has a full walkthrough, including the two things that trip everyone up: the Windows Firewall rule for the motor data, and the mirrored networking option that removes the need for any of it on Windows 11.

For the people who have a joystick without buttons, we have added hotkeys to switch ARM (A key) and Flight modes (M key). It works only if you didn't assigned this channels before.

The parts library got a big upgrade. NEW MOTORS — 9 Light/Mid/Heavy Generics covering 7", 10" and 13" frames. Includes a 4720-class 300KV on 12S for the heavy 13" lifters. REBALANCED — every motor in the catalog was rebalanced through a physics-based scaler. No more outliers (the 3115 900KV peak-current overshoot is gone), no more zero-iron-loss motors. NEW PROPS — rebuilt prop lineup; 13" and larger props now carry M5/M6/M8 adapter rings so a single SKU fits 5 mm and 6 mm shafts. NEW FRAME — 9IMOD F13 (13" X-frame, 385 g) added to the catalog. ELECTRONICS WEIGHT — your build's all-up-weight now includes 50 g for the FPV camera, VTX, antennas and mounts. The Workbench hover-throttle and flight-time numbers move accordingly.