Troubleshooting
Common issues and solutions for FreeBCI DAQ.
Browser Support
| Browser | Works? |
|---|---|
| Chrome 89+ (desktop) | Yes |
| Edge 89+ (desktop) | Yes |
| Firefox, Safari, Mobile | No |
"Browser does not support Web Serial" → Switch to Chrome or Edge.
Connection Issues
Device Not Found
- Check USB cable and device power
- Verify OS-level serial drivers
- Try a different USB port
- Run
ls /dev/tty.*(macOS) or check Device Manager (Windows)
ACK Timeout Errors
"Timed out waiting for serial initialization reset ACK" — device didn't respond to EEGRST within 2s. Verify firmware compatibility, baud rate (921600), and that no other app uses the port.
"Timed out waiting for hardware initialization ACK" — device rejected config parameters. Try default settings.
Stall Detection
"No valid serial EEG frame arrived for 2 seconds" — check if device is actively sampling. May auto-recover.
Stream Issues
Pre-conditions for starting stream:
- Hardware parameters confirmed (green badge)
- Site bindings confirmed
- Serial port connected
- CSV file selected (if CSV writes enabled)
AI Connection Issues
- Wrong Base URL → Verify endpoint matches provider
- Invalid API Key → Check for extra spaces
- Ollama not running →
ollama serve - CORS issues → Endpoint must support CORS from your origin
Performance
- Turn off Draw toggle to pause chart rendering while keeping data flowing
- IndexedDB write timeouts → export and clear old conversations
Still Stuck?
- Check System page for runtime status
- Verify pre-conditions in Hardware Setup
- Review Configuration
- Consult the FAQ