Common problems#
| Problem | Fix |
|---|---|
| START RECORDING is disabled or does nothing | Tick consent (or Simulation) and stop any running recording. Read the footer status and the red Cannot start line on Experiments: a required interface may be missing, or the flicker acknowledgement is needed. |
| Microphone is always silent | The OS is routing a muted or wrong input. Run --list-audio and choose a specific input in the Microphone source settings; check the OS sound settings. |
| “requested … Hz unsupported” | Choose Device default or a rate the device lists. |
| Camera unavailable | Check the camera index, close other apps using the camera and allow camera access in the OS privacy settings. Frame rate drops in dim light. |
| Output “not real-time paced” warning | A dummy audio output is selected. Choose a real device. |
| Loopback: “silent reference or response” | The microphone does not hear the speaker. Raise the volume slightly, move them closer or use a cable. |
| Pulse candidate always withheld | Record at least 10 s in steady light, keep still and fill the ROI box with skin. |
| Touch, HID or evdev PERMISSION_DENIED | See Optional permissions. Window keyboard, mouse and touch events work without them. |
| Gamepad not listed | Check the cable or pairing, then Refresh discovery. On Linux the controller also needs /dev/input access. |
| Visual stimulus timing uneven | Close heavy programs; check the measured refresh interval and late frames in Hardware → Displays. |
| Session marked complete with gaps | Data was dropped (disk or CPU overload, or an unpaced device). Check the drop counters on Recording and Settings; reduce camera resolution or raise the frame stride. |
| RTL-SDR not found or busy | See RTL-SDR troubleshooting. |
Many ALSA lib … lines in the terminal | Harmless messages printed while Linux audio devices are enumerated. |
| Settings or profiles missing | NOESIS was launched from a different folder. Launch from the folder that holds noesis-config.json. |
Optional permissions#
Some Linux interfaces are restricted by default and show PERMISSION_DENIED. NOESIS never changes permissions itself.
Raw keyboard, mouse and touch (evdev) Kernel timestamps
sudo usermod -aG input $USERLog out and back in. This lets every program you run read all keystrokes, including passwords.
HID input reports (/dev/hidraw*)
Create /etc/udev/rules.d/70-noesis-hidraw.rules containing:
KERNEL=="hidraw*", TAG+="uaccess"Then reload the rules:
sudo udevadm control --reload && sudo udevadm triggerSerial ports
Your user needs the dialout group (usually already set).
Windows privacy
Allow desktop apps to use the camera and microphone in Settings → Privacy & security.
Afterwards click Hardware → Refresh discovery; the status changes to AVAILABLE.