SolarOS 4.16.30 manual · app

rfscan

Graphical receiver-energy monitor for attached radios that report the live_rssi capability. Requires a graphical display and the radio_scanner group. Radio drivers provide live energy readings and validate tuning and bandwidth settings through the common radio API; the app does not select support by radio model.

rfscan
rfscan radio0
radio scan radio0

Select the radio at launch with rfscan <name>; it remains selected for that app session. With no argument the app selects the first attached radio. The radio configuration TUI also opens the scanner with s on a graphical display. From a text-only shell, use session create rfscan display0 radio0 to open it on the device display.

Channel plots live RSSI against time. Time cycles through 10 seconds, 1 minute, 10 minutes and 1 hour. Sampling intervals increase with the time window; short bursts can be missed. The graph shows the latest level and the minimum and peak since starting or clearing. When another service is already receiving, the scanner observes without retuning, consuming packets or taking its radio claim. Transmit and sleep intervals produce no energy samples. An idle radio is claimed and placed in receive mode until scanning stops.

PgUp zooms into the RSSI plot's Y axis and PgDown zooms out. Available spans are 5, 10, 25, 50, 100 and 200 dB; the default is 100 dB. In Channel, the plot centers on the average RSSI of samples inside the displayed time window. In Band, it centers on the average of the current frequency-bin readings. Empty bins and held peaks do not affect the average. Each zoom key centers the axis on that average, then holds the axis steady until the next zoom key. The Avg readout continues updating; values outside the selected span are clipped to the plot edges. Zoom leaves scanning and the alert threshold unchanged and does not change waterfall shading. A threshold outside the visible Y range keeps working but its horizontal marker is hidden.

Channel controls are Start/Stop, Time, Step, Freq and Thresh. Step selects a frequency increment of 25, 62.5, 125 or 250 kHz without interrupting monitoring. With Freq selected, Up/Down increases/decreases the requested frequency by that increment; the frequency is shown to 1 Hz. Changing frequency applies it and resumes acquisition automatically when monitoring was running. Tuning requires an unclaimed radio and preserves the current receiver bandwidth. A busy radio reports its owner. Stop, suspension or exit restores the previous frequency and operating state.

Enter on a setting opens a prefilled input popup. Type to replace the current value, use Left/Right, Home/End, Backspace or Delete to edit, or Ctrl+U to clear the field. Enter applies and Esc cancels. Frequency uses MHz; Step and BW use kHz, including decimal values. A BW of 0 keeps the current receiver filter. Range accepts start and end frequencies in MHz separated by a space; Time accepts 1–3600 seconds. Values that would exceed the supported number of scan bins are rejected or require a larger step. Radio drivers validate frequency and bandwidth when scanning starts. Opening or cancelling a popup leaves the current scan running.

Thresh controls an audible energy alert in both tabs. The default is −90 dBm; Up/Down changes it by 1, 1, 1, 2, 5 or 10 dB for Y spans of 5, 10, 25, 50, 100 or 200 dB, respectively, and cycles through Off at the ends of the −130 to −30 dBm range. Enter accepts an exact dBm value or off. Changing the threshold leaves scanning running. A dashed horizontal line marks the threshold; fresh samples at or above it request a short beep at most once per second, including brief hits between graphical refreshes. Alerts use the selected audio output and global volume/mute, skip busy audio, and are cancelled on Stop, suspension or exit. Audio failures are reported without ending the scan. The center frequency of the strongest sample responsible for the last alert is shown beside the threshold as Threshold: >=-90dBm Triggered: 868.375000MHz. Before the first alert, Triggered shows --. The frequency remains visible while scanning moves on; the next alert updates it.

Band shows received energy against frequency, a dashed peak trace and a waterfall with the newest completed sweep at the top. Darker pixels mean stronger energy. The waterfall uses dithering on 1-bit displays; buttons use solid backgrounds, outlines and inverse selection. Range cycles through ±250 kHz, ±1 MHz, ±2 MHz and a preset band: 433.05–434.79, 863–870 or 902–928 MHz, selected from the current frequency. Step cycles through 25, 62.5, 125 and 250 kHz; wide ranges increase the step when necessary to stay within 129 frequency bins. BW selects the current receiver bandwidth or 62.5, 125 or 250 kHz. Drivers can round the requested bandwidth up to a supported filter; the running scan shows the applied bandwidth. Unsupported settings are rejected by the radio driver. The final frequency shown is the last sampled bin.

Three status lines above the graph show tuning settings, RSSI readings and the alert threshold with the last alert frequency. Errors replace the RSSI readings. The top header shows LIVE with owns RX, observe RX or RX paused for a band sweep; stopped acquisition shows STOPPED. In Channel, the header also shows the time window. The tuning row shows the frequency or band range, with BW: and Step: labels. Sampling runs independently of graphical refreshes. Radios advertising fast_tune use lightweight frequency changes and driver-defined settling times; other live_rssi radios remain supported through normal configuration. Sweep speed depends on the driver, bandwidth, range and frequency step.

Band scans require exclusive ownership of the selected radio. A busy radio shows its owner; stop that owner explicitly before scanning. Normal packet reception on that radio is paused during a sweep. Band scanning has no idle timeout. Stop, app suspension, app exit or a scan error ends the sweep. The scanner restores the previous configuration and operating state and releases its claim; a restoration failure is reported. Changing settings or switching tabs automatically resumes acquisition if it was running; a stopped scan stays stopped. Rejected settings restore the previous selection and resume it when radio ownership permits. Returning to a suspended app leaves it stopped until Start is selected.

RSSI measures energy inside the receiver filter without decoding its source. Frequency bins are sampled sequentially; receiver bandwidth limits frequency detail. Scan only within the attached module's supported RF band and antenna range. This display does not provide raw I/Q samples.