run 6

docs/discovery-notes.md

@@ -2731,3 +2731,116 @@ Next CALL-focused checks:
    which of the two echoed frames causes `07 80 45 20 D0 68`.
 3. Try using `07 80 45 20 D0 68` as a follow-up host frame after CALL exact
    echo, only after confirming repeatability.
+
+### Real-World CALL Hold/Release Test
+
+Goal: mimic how CALL would likely work in use:
+
+```text
+User holds CALL     -> RCP sends CALL high/on
+Host responds high  -> host echoes/acknowledges CALL high/on
+User releases CALL  -> RCP sends CALL low/off
+Host responds low   -> host echoes/acknowledges CALL low/off
+```
+
+Test BTN8: mirror CALL high and low once per state.
+
+```powershell
+python scripts/serial_button_response_test.py --port COM5 --duration 30 --prompt --mirror-call --mirror-call-once-per-state --log captures/rcp-buttons-call-mirror-hold-release.txt
+```
+
+Procedure:
+
+1. Power-cycle the RCP.
+2. Start the command and press Enter at the prompt.
+3. Hold `CALL` for about 2 seconds.
+4. Release `CALL`.
+5. Watch whether the screen changes and note the final screen text.
+
+Interpretation:
+
+- If the RCP again sends `07 80 45 20 D0 68`, the frame is likely part of the
+  CALL response path.
+- If the screen still ends at `CONNECT NOT ACT`, this mirrors CALL signaling but
+  still does not satisfy the active-session handshake.
+
+Optional latched version:
+
+```powershell
+python scripts/serial_button_response_test.py --port COM5 --latch --latch-query-command 0xB5 --duration 30 --prompt --mirror-call --mirror-call-once-per-state --log captures/rcp-buttons-latched-call-mirror-hold-release.txt
+```
+
+### 2026-05-13 Latched CALL Mirror Result
+
+Capture:
+
+- `captures/rcp-buttons-latched-call-mirror-hold-release.txt`
+
+The capture contains three appended latched runs. Each run sent the `00 -> B5`
+latch setup, then mirrored observed CALL high/low events with the matching CALL
+frame.
+
+Observed result:
+
+- The RCP still emitted CALL high/low frames while latched.
+- The mirror script sent `CALL high mirror` and/or `CALL low mirror` responses
+  as expected.
+- No run reproduced the earlier exact-echo response
+  `07 80 45 20 D0 68`.
+- Serial output returned to heartbeat/CALL event traffic.
+
+Interpretation:
+
+- The earlier `07 80 45 20 D0 68` response appears tied to sending both CALL
+  echo frames immediately after CALL high, not to a realistic held/released CALL
+  mirror sequence.
+- Mirroring CALL state while latched does not appear to activate or unlatch the
+  RCP.
+- The latched state continues to allow front-panel CALL events to be transmitted.
+
+Tooling note:
+
+- `scripts/serial_button_response_test.py` now clears the serial input buffer
+  immediately after the manual prompt. This avoids stale frames collected while
+  waiting at the prompt contaminating button timing in future hold/release
+  tests.
+
+Clean non-latched repeat, if needed:
+
+```powershell
+python scripts/serial_button_response_test.py --port COM5 --duration 30 --prompt --mirror-call --mirror-call-once-per-state --log captures/rcp-buttons-call-mirror-hold-release.txt
+```
+
+### CALL Exact-Echo Reproducibility Test
+
+Goal: determine whether the new frame `07 80 45 20 D0 68` is reproducible when
+using the artificial exact-CALL echo that originally produced it.
+
+Test BTN9: repeat exact CALL echo and explicitly watch for `07 80 45 20 D0 68`.
+
+```powershell
+python scripts/serial_button_response_test.py --port COM5 --duration 15 --prompt --respond-to-call --respond-once --response-frame "00 00 15 80 00 CF" --response-frame "00 00 15 00 00 4F" --watch-frame "07 80 45 20 D0 68" --log captures/rcp-buttons-call-exact-echo-repro-1.txt
+```
+
+Run the same command three times, changing only the log filename:
+
+```powershell
+python scripts/serial_button_response_test.py --port COM5 --duration 15 --prompt --respond-to-call --respond-once --response-frame "00 00 15 80 00 CF" --response-frame "00 00 15 00 00 4F" --watch-frame "07 80 45 20 D0 68" --log captures/rcp-buttons-call-exact-echo-repro-2.txt
+python scripts/serial_button_response_test.py --port COM5 --duration 15 --prompt --respond-to-call --respond-once --response-frame "00 00 15 80 00 CF" --response-frame "00 00 15 00 00 4F" --watch-frame "07 80 45 20 D0 68" --log captures/rcp-buttons-call-exact-echo-repro-3.txt
+```
+
+Procedure for each run:
+
+1. Power-cycle the RCP.
+2. Start the command and press Enter at the prompt.
+3. Press `CALL` once.
+4. Stop after the script exits, then power-cycle before the next run.
+
+Interpretation:
+
+- If `Watch totals: 07 80 45 20 D0 68=1` appears consistently, the frame is a
+  reproducible response to artificial exact CALL echo.
+- If it appears intermittently, timing or current panel state is probably part
+  of the trigger.
+- If it does not appear, the original hit may have depended on a very specific
+  press/release timing or buffered frame ordering.