Novint Falcon → Simulink (Windows 11 + MATLAB R2022b+ / win64) Student Kit

This kit builds a Simulink S-function named sfunc_haptics that connects to a Novint Falcon haptic device.

What you get

• haptics.cpp / haptics.h: HDAL-style haptics wrapper (position out, force in)
• sfunc_haptics.cpp: Simulink S-function interface (Legacy Code Tool)
• Simulink example models from the original course zip (PD controller, etc.)
• A Win64 build script: build_sfunc_haptics_win64.m

Big picture (important)

The original course materials used Novint's HDAL SDK directly. On modern Windows 11 + 64-bit MATLAB, the easiest reliable approach is:

1. Build/install libnifalcon (open-source Falcon driver) and the HDAL compatibility layer libnifalcon_hdal
2. Compile the existing HDAL-style wrapper and S-function into mexw64
3. Run the provided Simulink models (fixed-step discrete)

Reference:

• libnifalcon repo (mentions bundled firmware requirement): https://github.com/libnifalcon/libnifalcon
• libnifalcon_hdal repo (HDAL compatibility layer): https://github.com/libnifalcon/libnifalcon_hdal
• MATLAB supported compilers list: https://www.mathworks.com/support/requirements/supported-compilers.html

If your lab already has a genuine 64-bit HDAL SDK with x64 hdl.lib, you can link against that instead. Otherwise, use the compatibility layer.

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Prerequisites (Windows 11)

Install these once per machine:

• MATLAB R2022b or newer (64-bit)
• Visual Studio 2022 (or Build Tools) with Desktop development with C++
• CMake (and make sure it’s on PATH)
• Git

MATLAB compiler setup

In MATLAB:

mex -setup C++

Choose the Visual Studio 2022 compiler MATLAB finds.

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Step 1 — Build & install libnifalcon + libnifalcon_hdal (HDAL compat)

Open “x64 Native Tools Command Prompt for VS 2022” (or a Developer PowerShell).

Choose a working folder, e.g. C:\dev\falcon, then run:

mkdir C:\dev\falcon
cd C:\dev\falcon

git clone https://github.com/libnifalcon/libnifalcon.git
git clone https://github.com/libnifalcon/libnifalcon_hdal.git

Build libnifalcon

mkdir build-libnifalcon
cd build-libnifalcon

cmake ..\libnifalcon -A x64 -DCMAKE_INSTALL_PREFIX=C:\dev\falcon\install
cmake --build . --config Release
cmake --install . --config Release

Build libnifalcon_hdal

cd C:\dev\falcon
mkdir build-hdal
cd build-hdal

cmake ..\libnifalcon_hdal -A x64 -DCMAKE_INSTALL_PREFIX=C:\dev\falcon\install -DCMAKE_PREFIX_PATH=C:\dev\falcon\install
cmake --build . --config Release
cmake --install . --config Release

After install, you should have:

• C:\dev\falcon\install\include\...
• C:\dev\falcon\install\lib\... (look for hdl.lib or libhdl.lib)

Firmware note (common gotcha)

libnifalcon requires firmware files shipped in its source distribution (see firmware/). If utilities cannot find/load firmware, copy the firmware folder somewhere predictable and ensure your setup follows libnifalcon’s guidance.

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Step 2 — Point this kit at your installed include/lib folders

In this kit, create a folder named EXTERNAL next to the MATLAB script:

• EXTERNAL\include → copy (or point to) C:\dev\falcon\install\include
• EXTERNAL\lib → copy (or point to) C:\dev\falcon\install\lib

Simplest for students:

# from the kit folder
mkdir EXTERNAL
mkdir EXTERNAL\include
mkdir EXTERNAL\lib
xcopy /E /I C:\dev\falcon\install\include EXTERNAL\include
xcopy /E /I C:\dev\falcon\install\lib     EXTERNAL\lib

(Alternatively edit the two paths inside build_sfunc_haptics_win64.m.)

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Step 3 — Build the Simulink S-function (mexw64)

From MATLAB, cd into the kit folder and run:

run build_sfunc_haptics_win64.m

Expected output file:

• sfunc_haptics.mexw64

If compilation fails with cannot open file 'hdl.lib':

• check EXTERNAL\lib for the actual library name
• update def.HostLibFiles / def.TargetLibFiles in the MATLAB script to match (e.g., libhdl.lib)

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Step 4 — Run the Simulink examples

Open one of the provided models, e.g.:

• hapticsSimBlk_pd.mdl (PD control demo)

Recommended Simulink settings (haptics stability):

• Solver: Fixed-step
• Type: Discrete (no continuous states)
• Fixed-step size: 0.001 (1 ms)

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Troubleshooting

Device not detected

• Unplug/replug the Falcon
• Try a different USB port (avoid unpowered hubs)
• Confirm Windows sees the device in Device Manager
• Ensure any required USB driver stack is installed (varies by Falcon hardware revisions)

mex cannot find a compiler

• Re-run:

  mex -setup C++

• Ensure Visual Studio 2022 C++ workload is installed

mex builds but Simulink errors loading mex

• You may be missing runtime DLLs from your build/install. Ensure the bin output from your install (if any DLLs) is on PATH, or place required DLLs next to the mex.

Force directions / scaling feel “wrong”

The wrapper applies workspace scaling and a transform matrix in haptics.cpp. For teaching labs, it can be useful to:

• log raw position
• verify sign conventions per axis
• apply simple gain scaling in Simulink first

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Instructor notes (what to forward)

Send students:

• This single ZIP kit
• The build instructions above
• Optionally, a prebuilt EXTERNAL folder for your lab image to avoid per-student library installs