docs: mark pinout schematic-verified; note reference PDFs

Verified board_config.h against the newly-added board schematic
(docs/esp32-p4_schematic_en.pdf) — all pins correct, including I2S data
direction (DOUT/GPIO9 -> ES8311 DSDIN, DIN/GPIO11 <- ES8311 ASDOUT) and
the NS4150B amplifier on the PA-enable line.

- board_config.h / README / CLAUDE.md: reword "ESPHome profile" to
  "board schematic"; add NS4150B; note the I2S data-direction mapping.
- REFERENCES.md: list the local datasheet / schematic / TRM copies.

No pin values changed — this only records that they are now confirmed
against the authoritative source.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

CLAUDE.md

@@ -56,10 +56,12 @@ idf.py flash monitor
 ## Target hardware
 
 Target board is the **Waveshare ESP32-P4-ETH** — Ethernet via IP101 GRI PHY
-(RMII), onboard ES8311 codec (APLL-clocked I2S) + amplifier + mic + speaker
-connector, 32MB PSRAM, 32MB flash. Pins are confirmed and live in
-`main/board_config.h`, with the full table in README.md. If the board ever
-changes, update `main/board_config.h` and the README table together.
+(RMII), onboard ES8311 codec (APLL-clocked I2S) + NS4150B amplifier + mic +
+8ohm speaker connector, 32MB PSRAM, 32MB flash. Pins are verified against the
+board schematic (`docs/esp32-p4_schematic_en.pdf`) and live in
+`main/board_config.h`, with the full table in README.md. Board datasheet and
+the P4 SoC TRM are also in `docs/`. If the board ever changes, update
+`main/board_config.h` and the README table together.
 
 ## Known hard problems
 

README.md

@@ -55,9 +55,9 @@ component.
 Target board: **Waveshare ESP32-P4-ETH**
 ([product](https://www.waveshare.com/esp32-p4-eth.htm) ·
 [wiki](https://www.waveshare.com/wiki/ESP32-P4-ETH)). Ethernet via IP101 GRI
-PHY (RMII); onboard ES8311 codec + amplifier + microphone + 8Ω speaker
-connector; 32 MB PSRAM, 32 MB NOR flash. Pins below are confirmed against the
-board's published pinout / ESPHome device profile and are mirrored in
+PHY (RMII); onboard ES8311 codec + NS4150B amplifier + microphone + 8Ω speaker
+connector; 32 MB PSRAM, 32 MB NOR flash. Pins below are verified against the
+board schematic (`docs/esp32-p4_schematic_en.pdf`) and are mirrored in
 `main/board_config.h`.
 
 | Function | GPIO | Notes |

docs/REFERENCES.md

@@ -10,4 +10,11 @@ https://github.com/voc/aes67-recorder
 
 ## ESP32-P4 Dev 
 https://www.waveshare.com/esp32-p4-eth.htm
-https://docs.waveshare.com/ESP32-P4-ETH
+https://docs.waveshare.com/ESP32-P4-ETH
+
+### Local copies (in this folder)
+
+- `ESP32-P4-ETH-datasheet.pdf` — Waveshare board datasheet
+- `esp32-p4_schematic_en.pdf` — board schematic (authoritative pinout;
+  `main/board_config.h` is derived from this)
+- `esp32-p4_technical_reference_manual_en.pdf` — ESP32-P4 SoC TRM

main/board_config.h

@@ -2,11 +2,15 @@
  * board_config.h — hardware pin map for the ESP32-P4 Dante/AES67 endpoint.
  *
  * Target board: Waveshare ESP32-P4-ETH (Ethernet via IP101 GRI PHY on RMII,
- * onboard ES8311 codec + amplifier + mic + speaker connector, 32MB PSRAM,
- * 32MB flash). Pins confirmed against the board's published pinout / ESPHome
- * device profile. Values mirror the pin table in README.md — if the board
- * ever changes, update BOTH this file and the README table together
- * (see CLAUDE.md).
+ * onboard ES8311 codec + NS4150B amplifier + mic + 8ohm speaker connector,
+ * 32MB PSRAM, 32MB flash). Pins verified against the board schematic
+ * (docs/esp32-p4_schematic_en.pdf). Values mirror the pin table in README.md
+ * — if the board ever changes, update BOTH this file and the README table
+ * together (see CLAUDE.md).
+ *
+ * Note on I2S data direction: DOUT (GPIO9) drives the codec's DAC serial
+ * input (ES8311 DSDIN); DIN (GPIO11) reads the codec's ADC serial output
+ * (ES8311 ASDOUT).
  */
 #pragma once