Scanning

Monitor SubGHz radio activity across frequency bands

On this page

Monitor radio activity across 64 channels in real-time to detect signals on supported frequency bands. This needs a GhostESP with CC1101 SubGHz hardware and an attached antenna (see Hardware Support).

Scanning for Signals

On-Device UI

  1. Open Menu → SubGHz → Capture.
  2. Select Start from the popup menu to begin scanning.
  3. The device will scan the current frequency band.
  4. Signal strength is displayed across 64 channels.
  5. Use Cycle Frequency to switch between bands (315, 390, 433.92, 868.35, 915 MHz).
  6. Press Back to stop scanning.

CLI

# Start scanning on current frequency
subghz start

# Stop scanning
subghz stop

# Pause/resume scanning
subghz pause
subghz resume

# Cycle to next frequency band
subghz cycle_freq

# Check scanner status
subghz status

Frequency Bands

The scanner supports five common SubGHz bands. Cycle through them to find the one used by your target device:

  • 315 MHz - Common in North America for garage doors and remote controls
  • 390 MHz - Used by some security systems and remote controls
  • 433.92 MHz - Most common worldwide for garage doors, gates, and wireless sensors
  • 868.35 MHz - European standard for remote controls and alarm systems
  • 915 MHz - North America ISM band for various devices

Signal Strength Visualization

The scanner displays signal strength across 64 channels within the selected band. Higher bars indicate stronger signals. Use this to:

  • Identify active channels
  • Find the frequency of a transmitting device
  • Verify signal reception before capturing

Notes

  • SubGHz scanning requires CC1101 hardware with CONFIG_HAS_SUBGHZ enabled (shipped builds: Banshee S3 only). CONFIG_HAS_SUBGHZ_REMOTE (Banshee C5 only) only enables a display-only remote UI that routes commands to a peer - it does not enable scanning itself.
  • Scanning is mutually exclusive with other SubGHz operations; starting a new scan will stop any ongoing capture or transmission.
  • Some devices transmit intermittently; leave the scanner running for several minutes to detect periodic signals.

Troubleshooting

  • No signals detected: Try different frequency bands or move closer to the target device. Ensure the antenna is properly connected.
  • Scanner fails to start: Check that your device has SubGHz hardware enabled. Verify SPI pin configuration in the build config.
  • Weak signals: Improve antenna placement or use a higher-gain antenna compatible with the CC1101 frequency range.