Heltec V4-R8 — "are we getting full performance?" audit. Compute side was already
at spec; six gaps closed (record: variants/heltec_v4/R8_AUDIT.md "Perf pass"):
- FEM LNA defaulted OFF on a KCT8103L board: prefs v49 defaults it ON on the R8
(one-time flip of existing installs, no new field). Toggle stays in Radio & Mesh.
- Display SPI 40 -> 80 MHz (LGFX_SPI_WRITE_HZ; -D to 40000000 steps back).
- Async DMA band flush (LGFXDisplay::flushBandRGB565): swap into a 12 KB internal
DMA buffer, one no-convert DMA per band, lv_disp_flush_ready at once so LVGL
renders band N+1 while band N drains; lv_disp_flush_is_last closes the frame
transaction so the shared micro-SD gets the bus between frames. Sync fallback.
- Wi-Fi modem power save is a pref (wifi_ps; toggle in Wi-Fi settings, live once
associated). Default ON everywhere (unchanged), OFF on the R8.
- micro-SD 4 -> 20 MHz after the proven mount, read-verified (probe-file head
captured at 4 MHz and byte-compared after the raise; falls back). Wired at all
three mount sites; no-op without SD_SPI_FAST_HZ. Note: SDFS::begin returns true
if already mounted, so every clock change goes through SD.end() first.
- R8 env boots at ESP32_CPU_FREQ=240 (setup() no longer runs at the V4's 80 MHz).
- Settings -> About "Perf:" row on the R8 (no serial console on that board):
"CPU 240 · TFT 80 MHz DMA · SD 20 MHz · LNA on" is the all-green reading.
ThinkNode M9 UI:
- Spectrum page root gets NAV_SKIP_FLAG: nothing on it is actionable, so the
d-pad no longer highlights the chart / scale box; Back closes it as before.
- Map "Show tile z/x/y" line defaults OFF (prefs v50, one-time flip; toggle kept).
- The tab bar is bypassed entirely on the M9: the accent "glow" indicator lived on
the screen, not in the bar, so hiding the zero-height bar left it glowing over
the content's bottom edge. No bar styling / gestures / key hints / indicator
are built on the M9 now.
Cross-compiled: R8, V4, M9, T-Deck. Flashed + booted on the user's R8 and M9.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
