OrcSDR v0.3.0-beta.2 — release notes

Prepared 2026-10-02. Previous release: v0.3.0-beta.1.

These notes describe v0.3.0-beta.2 and its completed tests. The four-dongle dashboard, ADS-B and replug checks have completed, and the Windows settings-preserving installer has been run successfully on the bench Tab5. The release was approved for publication on 2026-10-02; the owner reports the M5Burner listing is publicly available.

An M5Burner installation resets saved settings. The Windows settings-preserving installer keeps the settings area and existing C6 firmware.

The short version

• A newer driver, esp_rtl_sdr v0.9.3. The tuner's RF filter now follows the frequency you tune, so the Blog V3c and the
  Nooelec hear well away from FM, and the Blog V4 gains about 4 dB at 230 MHz; unplugging a dongle mid-stream or a dongle that
  fails to enumerate is handled instead of leaving the USB stack stuck. Details below.
• An Airband dashboard: an AM scanner with an airport catalog and receiver location, a voice band-pass, a persistent fixed
  gain, and a live SCOPE tab with spectrum and waterfall.
• Fluid scopes: FM, Airband, Shortwave, AM, CB and P25 spectrum views now redraw smoothly, with waterfall style chips; the FM
  view has clearer status badges, separate left and right meters, an IQ indicator and peak hold.
• Tab5 keyboard support, a reworked Home layout with palettes, and a filter popup.
• The C6 radio: firmware 2.12.6 and 3.0.6 are both accepted, and the update to 3.0.6 is optional (3.0.6 stops M5 Launcher's
  Wi-Fi/OTA from working).
• Fixes: a boot hang after a software restart (about one in five restarts, #127)
  and a crash when unplugging a dongle while audio was playing (the speaker could be released twice).

Using OrcSDR with M5Launcher

Keep C6 firmware 2.12.6 if you want to retain M5Launcher's Wi-Fi and OTA functions. OrcSDR supports C6 2.12.6 and 3.0.6. The OrcSDR host and C6 version numbers do not have to match for the tested Wi-Fi functions: this release was tested with host 3.0.6 and C6 2.12.6, including scanning, reconnecting to a saved profile and remaining connected during radio tests.

The OrcSDR firmware includes a C6 3.0.6 upgrade image. Applying it is optional and requires confirmation in Settings → Firmware & Updates. You do not need to apply it simply because the displayed versions differ.

Applying the C6 3.0.6 upgrade stops M5Launcher's Wi-Fi/OTA from working. If you use both applications, retain C6 2.12.6. This limitation concerns M5Launcher's Wi-Fi/OTA; it does not mean that every M5Launcher function stops working.

For a settings-preserving upgrade, unzip the Windows installer and run install.bat. It writes the Tab5 bootloader, partition table and OrcSDR application; it leaves the settings area and existing C6 firmware untouched. The bench installation kept the saved Wi-Fi profile, reconnected afterward and retained C6 2.12.6. Location was unset before and after the test; screen-rotation preservation was not separately measured.

These tests cover OrcSDR operation with the existing C6 configuration and the Windows installer. Installation or switching applications through M5Launcher itself has not been exercised in this release gate.

The driver: what is new in esp_rtl_sdr 0.9.3

OrcSDR now pins the published driver release v0.9.3 (it was v0.9.1). See the driver's
release notes for the detail.

• RF mux and tracking filter follow the tuned band (Blog V3c, Nooelec; V4 and V4L above 28.8 MHz). Before, the tuner stayed on
  the FM setting everywhere, so away from FM the stream ran but heard almost nothing. The band table comes from our own captures of
  the vendor driver. On a Tab5, 453.925 MHz went from about 17 dB to about 46 dB over noise on the Nooelec and from about 1 dB to
  40 to 45 dB on the V3c; the V4 gained about 4 dB at 230 MHz; the V4L is neutral.
• Unplugging a dongle, a dongle that fails to enumerate, and bad control transfers are handled: a bounded shutdown on unplug, a
  root-port power-cycle retry with back-off, and checks on control-transfer sizes.
• Nooelec: a manual gain no longer breaks every later start, and the low-band sample rates (225 to 300 kS/s) now start.
• The reports behind several of these came from David Coulson (@davidcoulson): the missing RF
  band select (driver #25), the unplug and enumeration failures (driver #26) and the low-band rate error (driver #24). His reports
  informed our investigation; the fixes were written and verified here.

What we tested

On a Tab5 with the owner's dongles, using development images built from the driver commits that became v0.9.3 (not yet the final
release image):

• Band select: Nooelec and V3c at 453.925 MHz peak 44 to 45 dB over noise with FM unchanged; V4 at 230 MHz 9.3 to 13.2 dB
  over noise with the change versus without, same dongle and antenna; the V4L streams and tunes correctly.
• Unplug and replug: five cycles on each of the Nooelec, V3c, V4 and V4L; every unplug was detected, re-probed and restarted,
  with no reboots and no leaked transfers. Two events are recorded honestly: on the V4 one stream start in seven replugs returned a
  USB error and the next replug recovered; on one V3c run the Wi-Fi link to the C6 failed during a replug and the Tab5 froze until
  it was reset (#109 and #110,
  already open for the V3). A rerun of the same V3c test passed cleanly.
• Build: the full ESP-IDF 5.5.4 build of OrcSDR succeeds; host tests and the documentation-truth check pass.

What we did not test

• The final release image on hardware (the exact-tag gate above: private M5Burner install, Home, FM audio, RTL-SDR, Wi-Fi scan,
  saved-profile connection, RF24, the UI regression command and the installer package).
• Hubs, long runs of this exact build, and any dongle, antenna or site other than the owner's.
• The Airband, scope and keyboard changes on dongles other than the ones used during their development.
• The V4L's band-select change against a build without it (it was neutral earlier; this was not repeated).

Known issues

Carried from beta.1 and still open: #117 (M5Burner install resets saved
settings), #116 (code-review findings not yet triaged),
#109, #110 and
#111 (V3 hot-plug can knock out the C6 link, an unrecovered link failure, and
a memory drop after repeated link recoveries), #78 (LoRa),
#72 (the AM Airband reception issue; the new Airband dashboard is this
release's work on it, not yet a closure) and the unsupported items listed in beta.1. Fixed since beta.1:
#127. Test-tool issue found on the way:
#153.

Changes since beta.1

#118 M5Burner install wording (settings reset),
#120 settings-safe installer package,
#121 V4L package results,
#123 and #124 dongle gate checks the applied bandwidth,
#128 boot hang after a software restart,
#130 C6 2.12.6 and 3.0.6,
#132 keyboard support, Home layout and palettes,
#133, #140 and #144 Airband,
#146 and #149 FM spectrum,
#150 scope fluidity for Shortwave, AM, CB and P25 and waterfall style chips,
#151 speaker release race on unplug, plus the driver pin to esp_rtl_sdr v0.9.3.