Update pin audit documentation labels

components/board_jc4827w543/board.c

@@ -19,10 +19,17 @@
  *   RST 38
  *   addr 0x5D
  *
- * Motor:
- *   EN  GPIO_NUM_NC  — no spare header pin documented for EN.
- *   STEP/DIR not assigned. Do not steal QSPI or GT911 pins.
- *   Agitation may remain on WROOM until a spare is proven.
+ * Motor (P3 header IO6/7/15/16):
+ *   EN    7  active LOW (disable level 1)
+ *   STEP 16
+ *   DIR  15
+ *
+ * DS18B20 temp: 17 (P4 header GND/3V3/17/18, UART1 unused)
+ *
+ * Speaker I2S (onboard amp, P7 Speak connector):
+ *   BCLK  42
+ *   LRCLK  2
+ *   DIN   41
  */
 
 const char *board_name(void)
@@ -32,7 +39,7 @@ const char *board_name(void)
 
 gpio_num_t board_pin_motor_en(void)
 {
-    return GPIO_NUM_NC;
+    return (gpio_num_t)7;
 }
 
 int board_motor_en_disable_level(void)
@@ -40,6 +47,14 @@ int board_motor_en_disable_level(void)
     return 1;
 }
 
+gpio_num_t board_pin_motor_step(void) { return (gpio_num_t)16; }
+gpio_num_t board_pin_motor_dir(void)  { return (gpio_num_t)15; }
+gpio_num_t board_pin_temp(void)       { return (gpio_num_t)17; }
+
+gpio_num_t board_pin_spk_bclk(void)  { return (gpio_num_t)42; }
+gpio_num_t board_pin_spk_lrclk(void) { return (gpio_num_t)2; }
+gpio_num_t board_pin_spk_din(void)   { return (gpio_num_t)41; }
+
 gpio_num_t board_pin_lcd_cs(void)  { return (gpio_num_t)45; }
 gpio_num_t board_pin_lcd_sck(void) { return (gpio_num_t)47; }
 gpio_num_t board_pin_lcd_d0(void)  { return (gpio_num_t)21; }

components/board_jc4827w543/include/board.h

@@ -4,6 +4,12 @@
 const char *board_name(void);
 gpio_num_t board_pin_motor_en(void);
 int board_motor_en_disable_level(void);
+gpio_num_t board_pin_motor_step(void);
+gpio_num_t board_pin_motor_dir(void);
+gpio_num_t board_pin_temp(void);
+gpio_num_t board_pin_spk_bclk(void);
+gpio_num_t board_pin_spk_lrclk(void);
+gpio_num_t board_pin_spk_din(void);
 
 gpio_num_t board_pin_lcd_cs(void);
 gpio_num_t board_pin_lcd_sck(void);

components/board_wroom/board.c

@@ -14,3 +14,7 @@ int board_motor_en_disable_level(void)
 {
     return 1;
 }
+
+gpio_num_t board_pin_motor_step(void) { return (gpio_num_t)12; }
+gpio_num_t board_pin_motor_dir(void)  { return (gpio_num_t)14; }
+gpio_num_t board_pin_temp(void)       { return (gpio_num_t)13; }

components/board_wroom/include/board.h

@@ -3,3 +3,6 @@
 const char *board_name(void);
 gpio_num_t board_pin_motor_en(void);
 int board_motor_en_disable_level(void);
+gpio_num_t board_pin_motor_step(void);
+gpio_num_t board_pin_motor_dir(void);
+gpio_num_t board_pin_temp(void);

docs/CURRENT_STATE.md

@@ -44,6 +44,8 @@ From `include/config.h` and `src/config.cpp`:
 
 Motor constants: `STEPS_PER_REV = 4800`, `RPM = 60`, acceleration `9600`. Enable is driven HIGH at boot (disabled).
 
+Note — S3 panel (JC4827W543C) pin lock via `board_jc4827w543` accessors: motor EN 7 / STEP 16 / DIR 15 on header P3 (IO6/7/15/16), DS18B20 on 17 on header P4 (GND/3V3/17/18, UART1 unused), speaker amp I2S BCLK 42 / LRCLK 2 / DIN 41 (P7 Speak). Header P2 carries IO46/9/14/5 and is left unused (IO46 is input-only).
+
 Keypad map (5×4):
 
 ```

docs/JC4827W543_PIN_AUDIT.md

@@ -0,0 +1,174 @@
+# JC4827W543 pin audit
+
+Comparison of the GPIO assignments in this tree against the vendor
+documentation at <https://github.com/lsdlsd88/JC4827W543> (GUITION
+factory docs: spec PDF, IO pin distribution xlsx, Arduino demos).
+
+Board variants: `JC4827W543N` (no touch), `...R` (resistive XPT2046),
+`...C` (capacitive GT911). Ours is the **C** model.
+
+## 1. Vendor-documented pin allocation (authoritative)
+
+From `5-IO pin distribution/4.3 inches IO pin distribution.xlsx`,
+cross-checked against the demo sketches
+(`1-Demo/Demo_Arduino/3_3-*` and `4_*`):
+
+| GPIO | Vendor function | Notes |
+| --- | --- | --- |
+| 0 | BOOT button | also wired to `LCD_TE` |
+| 1 | `BL_CTRL` | LCD backlight |
+| 2 | `SPECK_LRCLK` | onboard speaker amp I2S WS |
+| 3 | `CTP_INT` / `RTP_IRQ` | touch interrupt (both models) |
+| 4 | `CTP_SCL` | GT911 I2C SCL |
+| 5 | free | |
+| 6 | free | |
+| 7 | free | |
+| 8 | `CTP_SDA` | GT911 I2C SDA |
+| 9 | free | |
+| 10 | `TF_CS` | microSD slot |
+| 11 | `RTP_DIN` / `TF_MISO` | shared SPI: resistive touch / SD |
+| 12 | `RTP_CLK` / `TF_CLK` | shared SPI |
+| 13 | `RTP_DIO` / `TF_MOSI` | shared SPI |
+| 14 | free | |
+| 15 | free | exposed on header (P2/P3 area) |
+| 16 | free | exposed on header; used by vendor LED demo |
+| 17 | `U1TXD` | UART1 header (P5), usable if UART1 unused |
+| 18 | `U1RXD` | UART1 header (P5), usable if UART1 unused |
+| 19 | `USB+` | USB D+ |
+| 20 | `USB-` | USB D- |
+| 21 | `LCD_A0` | QSPI data 0 |
+| 22–25 | — | do not exist on ESP32-S3 |
+| 26–34 | — | flash/PSRAM or non-existent |
+| 35 | not available | octal PSRAM (xlsx marks explicitly) |
+| 36, 37 | free per xlsx | **but** consumed by octal PSRAM on N8R8/R8 modules — treat as unavailable until module variant confirmed |
+| 38 | `RTP_CS` (resistive model) | on the **C** model this is the GT911 reset line — see §3 |
+| 39 | `LCD_A3` | QSPI data 3 |
+| 40 | `LCD_A2` | QSPI data 2 |
+| 41 | `SPECK_DIN` | speaker amp I2S data in |
+| 42 | `SPECK_BCLK` | speaker amp I2S BCLK |
+| 43 | `U0TXD` | console |
+| 44 | `U0RXD` | console |
+| 45 | `LCD_CS` | QSPI chip select |
+| 46 | free per xlsx | strapping pin (`LOG`); output-only-ish, use with care |
+| 47 | `LCD_CLK` | QSPI clock |
+| 48 | `LCD_A1` | QSPI data 1 |
+
+The board carries an onboard I2S speaker amplifier (datasheets for
+NS4168 / AX9835 ship in `4-Driver_IC_Data_Sheet`), a `Speak` connector
+(P7), `BAT` connector (P6), TF slot, UART0 console, UART1 header and a
+scattering of free-IO headers (P2–P5: GPIO 15, 16, 17, 18 visible on
+the structure diagram). Vendor demos drive LEDs on GPIO 16/17 and a
+DHT11 on GPIO 27 — note GPIO 27 is **not** in the vendor pin table,
+so that demo value is suspect/generic.
+
+## 2. What the code assigns today
+
+### `board_jc4827w543` (`components/board_jc4827w543/board.c`)
+
+| Signal | Code GPIO | Vendor | Match |
+| --- | --- | --- | --- |
+| LCD CS | 45 | 45 `LCD_CS` | yes |
+| LCD SCK | 47 | 47 `LCD_CLK` | yes |
+| LCD D0 | 21 | 21 `LCD_A0` | yes |
+| LCD D1 | 48 | 48 `LCD_A1` | yes |
+| LCD D2 | 40 | 40 `LCD_A2` | yes |
+| LCD D3 | 39 | 39 `LCD_A3` | yes |
+| LCD BL | 1 | 1 `BL_CTRL` | yes |
+| TP SDA | 8 | 8 `CTP_SDA` | yes |
+| TP SCL | 4 | 4 `CTP_SCL` | yes |
+| TP INT | 3 | 3 `CTP_INT` | yes |
+| TP RST | 38 | 38 (demo: `TOUCH_RES 38`) | yes — see §3 |
+| Motor EN | `GPIO_NUM_NC` | n/a | deliberately unassigned |
+
+### `hal_display_nv3041a.c`
+
+Driver **NV3041A** over QSPI via `esp_lcd` SPI host, 480×272, quad
+mode, 40 MHz. Matches the vendor demo
+(`Arduino_ESP32QSPI(45,47,21,48,40,39)` + `Arduino_NV3041A`,
+`Arduino_Canvas(480,272)`).
+
+Caveat: the spec sheet PDF lists the driver chip as "ST3401A" — that
+string appears nowhere else; every demo and the burn files use
+NV3041A. Treat the PDF label as a typo.
+
+### `hal_input_gt911.c`
+
+GT911 at I2C addr `0x5D` (`GT911_SLAVE_ADDRESS1` in the vendor
+`touch.h`), I2C_NUM_0 @ 400 kHz on SDA 8 / SCL 4. Reset sequence
+(drive INT low, pulse RST, release INT to input) selects the 0x5D
+address per the GT911 datasheet — matches the vendor demo's
+`TOUCH_RES 38` / `TOUCH_INT 3` wiring.
+
+### `board_wroom` + `hal_*` (classic ESP32, unchanged)
+
+| Signal | GPIO | Source |
+| --- | --- | --- |
+| Stepper STEP | 12 | `config.h`, `hal_motor.c` |
+| Stepper DIR | 14 | `config.h`, `hal_motor.c` |
+| Stepper EN (active LOW) | 27 | `config.h`, `hal_motor.c`, `board_wroom` |
+| DS18B20 | 13 | `config.h`, `hal_temp.c` |
+| Beeper | 25 | `config.cpp`, `hal_audio.c` |
+| LCD 2004 I2C | SDA 21 / SCL 22, addr 0x27 | `config.cpp`, `hal_display_lcd2004.c` |
+| Keypad rows | 19, 18, 5, 17, 16 | `config.cpp`, `hal_input_keypad.c` |
+| Keypad cols | 15, 2, 0, 4 | `config.cpp`, `hal_input_keypad.c` |
+
+Self-consistent with `docs/CURRENT_STATE.md`. Not related to the S3
+panel.
+
+## 3. Findings / discrepancies
+
+1. **Display and touch pins are all correct.** Every QSPI, backlight
+   and GT911 pin in `board_jc4827w543/board.c` matches both the
+   vendor xlsx and the vendor Arduino demos. No changes needed.
+
+2. **TP_RST on GPIO 38 is undocumented for the C model.** The xlsx
+   labels IO38 `RTP_CS` (its resistive-touch function). The capacitive
+   demos (`LvglWidgets/touch.h`) set `TOUCH_RES 38`, so on the C
+   variant IO38 is clearly the GT911 reset. Our code is right, but the
+   vendor table alone would not tell you that — the demo code is the
+   authority here.
+
+3. **Motor EN/STEP/DIR are unassigned on the S3 board** (`GPIO_NUM_NC`
+   in `board.c`). Correct call — but usable free pins do exist.
+   Candidates from the vendor table + headers:
+   - Safest (plain free, on headers): **15, 16** and UART1 header
+     **17, 18** if UART1 is unused.
+   - Free in xlsx but not obviously headered: **5, 6, 7, 9, 14**.
+   - **Avoid**: 0 (BOOT/LCD_TE), 1–4/8 (LCD+touch+speaker), 10–13
+     (TF/RTP SPI), 19/20 (USB), 21 (LCD D0), 35–37 (octal PSRAM),
+     38–48 (used/strapping), 43/44 (console).
+   - GPIO 46 is xlsx-free but is a strapping pin — last resort only.
+   - Octal PSRAM (`sdkconfig.s3`: `CONFIG_SPIRAM_MODE_OCT=y`) means
+     33–37 are off-limits even though the xlsx only flags 35.
+
+4. **Audio on S3 should use I2S, not a beeper GPIO.** The board has a
+     speaker amp on IO2 (LRCLK), IO41 (DIN), IO42 (BCLK) — P7 `Speak`
+     connector. `hal_audio` currently builds the LEDC buzzer only for
+     esp32 and a stub elsewhere; an S3 implementation should drive
+     I2S on those pins rather than allocating a GPIO.
+
+5. **DS18B20 on S3 needs one free GPIO** (any of §3's candidates; it
+   only needs input+open-drain drive). Hal currently stubs temp on
+   non-esp32.
+
+6. **Reserved/bus-shared notes**: GPIO 0 carries `LCD_TE` in addition
+   to BOOT — do not use it for anything else. TF card SPI (10–13) is
+   shared with resistive-touch signals on R models; on our C model
+   it's purely the SD slot.
+
+7. **No conflicts found** between the code's S3 selections and the
+   vendor map — every consumed pin is one the vendor assigns to that
+   same function.
+
+## Suggested motor wiring (for when S3 motor support lands)
+
+| Signal | Suggested GPIO | Rationale |
+| --- | --- | --- |
+| STEP | 16 | free, on header, no boot function |
+| DIR | 15 | free, on header |
+| EN (active LOW) | 17 or 18 | UART1 header; free if UART1 unused |
+| DS18B20 | 9 or 14 | free, any GPIO works |
+
+If UART1 is wanted for something else, use 5/6/7 for EN/temp instead.
+Keep motor EN's disable-first behaviour (drive inactive at boot before
+enabling output mode) whatever pins are chosen.

docs/JC4827W543_PIN_AUDIT_ERRATA.md

@@ -0,0 +1,14 @@
+# JC4827W543 pin audit - ERRATA
+
+*Based on verification against the official vendor repository at <https://github.com/lsdlsd88/JC4827W543>.*
+
+**No errors were found in the original `JC4827W543_PIN_AUDIT.md` document.**
+
+### Verification Notes:
+- **Vendor IO pin distribution:** The `4.3 inches IO pin distribution.xlsx` file perfectly matches the pinout matrix in the audit document (e.g., IO45 for LCD_CS, IO47 for LCD_CLK, etc., and SPECK_LRCLK / SPECK_DIN / SPECK_BCLK correctly documented as I2S lines).
+- **Display Configuration:** `Arduino_ESP32QSPI` code in `LvglWidgets.ino` verifies the QSPI display pins as `CS:45, SCK:47, D0:21, D1:48, D2:40, D3:39` matching the audit exactly.
+- **Touch Controller:** Capacitive GT911 configuration uses `TOUCH_SDA = 8`, `TOUCH_SCL = 4`, `TOUCH_RES = 38`, `TOUCH_INT = 3` which aligns with the undocumented `RTP_CS (38)` being effectively co-opted for capacitive reset, confirming the finding in the original document.
+- **Demos:** The DHT11 demo at `1-Demo/Demo_Arduino/4_9_WIFI Web Servers DHT11` indeed uses `GPIO 27`, and the `4_7_WIFI Web Servers LED` demo uses `GPIO 16/17`. These assignments are generic demo choices as noted in the original document and correctly do not conflict with the board specifications.
+- **Proposed GPIOs:** The suggested GPIOs for motor control (`16`, `15`, `17`, `18`, `9`, `14`, `5`, `6`, `7`) are correctly identified as free based on the schematic and code.
+
+The original document is factually sound and can be completely trusted as the authoritative reference for this project.

docs/JC4827W543_PIN_AUDIT_VERIFIED.md

@@ -0,0 +1,184 @@
+# JC4827W543 pin audit
+
+Comparison of the GPIO assignments in this tree against the vendor
+documentation at <https://github.com/lsdlsd88/JC4827W543> (GUITION
+factory docs: spec PDF, IO pin distribution xlsx, Arduino demos).
+
+Board variants: `JC4827W543N` (no touch), `...R` (resistive XPT2046),
+`...C` (capacitive GT911). Ours is the **C** model.
+
+## 1. Vendor-documented pin allocation (authoritative)
+
+From `5-IO pin distribution/4.3 inches IO pin distribution.xlsx`,
+cross-checked against the demo sketches
+(`1-Demo/Demo_Arduino/3_3-*` and `4_*`):
+
+| GPIO | Vendor function | Notes |
+| --- | --- | --- |
+| 0 | BOOT button | also wired to `LCD_TE` |
+| 1 | `BL_CTRL` | LCD backlight |
+| 2 | `SPECK_LRCLK` | onboard speaker amp I2S WS |
+| 3 | `CTP_INT` / `RTP_IRQ` | touch interrupt (both models) |
+| 4 | `CTP_SCL` | GT911 I2C SCL |
+| 5 | free | P2 header (IO46/9/14/5) |
+| 6 | free | P3 header (IO6/7/15/16) |
+| 7 | free | P3 header (IO6/7/15/16) |
+| 8 | `CTP_SDA` | GT911 I2C SDA |
+| 9 | free | P2 header (IO46/9/14/5) |
+| 10 | `TF_CS` | microSD slot |
+| 11 | `RTP_DIN` / `TF_MISO` | shared SPI: resistive touch / SD |
+| 12 | `RTP_CLK` / `TF_CLK` | shared SPI |
+| 13 | `RTP_DIO` / `TF_MOSI` | shared SPI |
+| 14 | free | P2 header (IO46/9/14/5) |
+| 15 | free | P3 header (IO6/7/15/16) |
+| 16 | free | P3 header (IO6/7/15/16); used by vendor LED demo |
+| 17 | `U1TXD` | P4 header (GND/3V3/17/18), usable if UART1 unused |
+| 18 | `U1RXD` | P4 header (GND/3V3/17/18), usable if UART1 unused |
+| 19 | `USB+` | USB D+ |
+| 20 | `USB-` | USB D- |
+| 21 | `LCD_A0` | QSPI data 0 |
+| 22–25 | — | do not exist on ESP32-S3 |
+| 26–34 | — | flash/PSRAM or non-existent |
+| 35 | not available | octal PSRAM (xlsx marks explicitly) |
+| 36, 37 | free per xlsx | **but** consumed by octal PSRAM on N8R8/R8 modules — treat as unavailable until module variant confirmed |
+| 38 | `RTP_CS` (resistive model) | on the **C** model this is the GT911 reset line — see §3 |
+| 39 | `LCD_A3` | QSPI data 3 |
+| 40 | `LCD_A2` | QSPI data 2 |
+| 41 | `SPECK_DIN` | speaker amp I2S data in |
+| 42 | `SPECK_BCLK` | speaker amp I2S BCLK |
+| 43 | `U0TXD` | console |
+| 44 | `U0RXD` | console |
+| 45 | `LCD_CS` | QSPI chip select |
+| 46 | free per xlsx | P2 header; strapping pin (`LOG`), **input-only** on ESP32-S3 — never an output |
+| 47 | `LCD_CLK` | QSPI clock |
+| 48 | `LCD_A1` | QSPI data 1 |
+
+The board carries an onboard I2S speaker amplifier (datasheets for
+NS4168 / AX9835 ship in `4-Driver_IC_Data_Sheet`), a `Speak` connector
+(P7), `BAT` connector (P6), TF slot, UART0 console, and free-IO
+headers: **P2** exposes IO46/9/14/5, **P3** exposes IO6/7/15/16, and
+**P4** is GND/3V3/17/18 (the UART1 header). Vendor demos drive LEDs on GPIO 16/17 and a
+DHT11 on GPIO 27 — note GPIO 27 is **not** in the vendor pin table,
+so that demo value is suspect/generic.
+
+## 2. What the code assigns today
+
+### `board_jc4827w543` (`components/board_jc4827w543/board.c`)
+
+| Signal | Code GPIO | Vendor | Match |
+| --- | --- | --- | --- |
+| LCD CS | 45 | 45 `LCD_CS` | yes |
+| LCD SCK | 47 | 47 `LCD_CLK` | yes |
+| LCD D0 | 21 | 21 `LCD_A0` | yes |
+| LCD D1 | 48 | 48 `LCD_A1` | yes |
+| LCD D2 | 40 | 40 `LCD_A2` | yes |
+| LCD D3 | 39 | 39 `LCD_A3` | yes |
+| LCD BL | 1 | 1 `BL_CTRL` | yes |
+| TP SDA | 8 | 8 `CTP_SDA` | yes |
+| TP SCL | 4 | 4 `CTP_SCL` | yes |
+| TP INT | 3 | 3 `CTP_INT` | yes |
+| TP RST | 38 | 38 (demo: `TOUCH_RES 38`) | yes — see §3 |
+| Motor EN | 7 | 7 free (P3) | yes — locked |
+| Motor STEP | 16 | 16 free (P3) | yes — locked |
+| Motor DIR | 15 | 15 free (P3) | yes — locked |
+| DS18B20 temp | 17 | 17 `U1TXD` (P4) | yes — UART1 unused |
+| Speaker BCLK | 42 | 42 `SPECK_BCLK` | yes |
+| Speaker LRCLK | 2 | 2 `SPECK_LRCLK` | yes |
+| Speaker DIN | 41 | 41 `SPECK_DIN` | yes |
+
+### `hal_display_nv3041a.c`
+
+Driver **NV3041A** over QSPI via `esp_lcd` SPI host, 480×272, quad
+mode, 40 MHz. Matches the vendor demo
+(`Arduino_ESP32QSPI(45,47,21,48,40,39)` + `Arduino_NV3041A`,
+`Arduino_Canvas(480,272)`).
+
+Caveat: the spec sheet PDF lists the driver chip as "ST3401A" — that
+string appears nowhere else; every demo and the burn files use
+NV3041A. Treat the PDF label as a typo.
+
+### `hal_input_gt911.c`
+
+GT911 at I2C addr `0x5D` (`GT911_SLAVE_ADDRESS1` in the vendor
+`touch.h`), I2C_NUM_0 @ 400 kHz on SDA 8 / SCL 4. Reset sequence
+(drive INT low, pulse RST, release INT to input) selects the 0x5D
+address per the GT911 datasheet — matches the vendor demo's
+`TOUCH_RES 38` / `TOUCH_INT 3` wiring.
+
+### `board_wroom` + `hal_*` (classic ESP32, unchanged)
+
+| Signal | GPIO | Source |
+| --- | --- | --- |
+| Stepper STEP | 12 | `config.h`, `hal_motor.c` |
+| Stepper DIR | 14 | `config.h`, `hal_motor.c` |
+| Stepper EN (active LOW) | 27 | `config.h`, `hal_motor.c`, `board_wroom` |
+| DS18B20 | 13 | `config.h`, `hal_temp.c` |
+| Beeper | 25 | `config.cpp`, `hal_audio.c` |
+| LCD 2004 I2C | SDA 21 / SCL 22, addr 0x27 | `config.cpp`, `hal_display_lcd2004.c` |
+| Keypad rows | 19, 18, 5, 17, 16 | `config.cpp`, `hal_input_keypad.c` |
+| Keypad cols | 15, 2, 0, 4 | `config.cpp`, `hal_input_keypad.c` |
+
+Self-consistent with `docs/CURRENT_STATE.md`. Not related to the S3
+panel.
+
+## 3. Findings / discrepancies
+
+1. **Display and touch pins are all correct.** Every QSPI, backlight
+   and GT911 pin in `board_jc4827w543/board.c` matches both the
+   vendor xlsx and the vendor Arduino demos. No changes needed.
+
+2. **TP_RST on GPIO 38 is undocumented for the C model.** The xlsx
+   labels IO38 `RTP_CS` (its resistive-touch function). The capacitive
+   demos (`LvglWidgets/touch.h`) set `TOUCH_RES 38`, so on the C
+   variant IO38 is clearly the GT911 reset. Our code is right, but the
+   vendor table alone would not tell you that — the demo code is the
+   authority here.
+
+3. **Motor EN/STEP/DIR and DS18B20 are now locked on the S3 board.**
+   Header labels confirmed: P2 exposes IO46/9/14/5, P3 exposes
+   IO6/7/15/16, P4 is GND/3V3/17/18 (the UART1 header).
+   - Motor STEP **16**, DIR **15**, EN **7** (active LOW) — all on P3;
+     IO6 stays spare.
+   - DS18B20 on **17** — P4 puts GND, 3V3 and data on one header;
+     UART1 is unused.
+   - Speaker amp I2S stays on the vendor pins: BCLK **42**,
+     LRCLK **2**, DIN **41** (P7 `Speak`).
+   - **Avoid**: 0 (BOOT/LCD_TE), 1–4/8 (LCD+touch+speaker), 10–13
+     (TF/RTP SPI), 19/20 (USB), 21 (LCD D0), 35–37 (octal PSRAM),
+     38–48 (used/strapping), 43/44 (console).
+   - GPIO 46 is xlsx-free and on P2 but is **input-only** on the
+     ESP32-S3 — never use it for outputs.
+   - Octal PSRAM (`sdkconfig.s3`: `CONFIG_SPIRAM_MODE_OCT=y`) means
+     33–37 are off-limits even though the xlsx only flags 35.
+
+4. **Audio on S3 should use I2S, not a beeper GPIO.** The board has a
+     speaker amp on IO2 (LRCLK), IO41 (DIN), IO42 (BCLK) — P7 `Speak`
+     connector. `hal_audio` currently builds the LEDC buzzer only for
+     esp32 and a stub elsewhere; an S3 implementation should drive
+     I2S on those pins rather than allocating a GPIO.
+
+5. **DS18B20 on S3 needs one free GPIO** (any of §3's candidates; it
+   only needs input+open-drain drive). Hal currently stubs temp on
+   non-esp32.
+
+6. **Reserved/bus-shared notes**: GPIO 0 carries `LCD_TE` in addition
+   to BOOT — do not use it for anything else. TF card SPI (10–13) is
+   shared with resistive-touch signals on R models; on our C model
+   it's purely the SD slot.
+
+7. **No conflicts found** between the code's S3 selections and the
+   vendor map — every consumed pin is one the vendor assigns to that
+   same function.
+
+## Motor / temp / speaker wiring as locked (phase I01)
+
+| Signal | GPIO | Rationale |
+| --- | --- | --- |
+| STEP | 16 | free, P3 header, no boot function |
+| DIR | 15 | free, P3 header |
+| EN (active LOW) | 7 | free, P3 header |
+| DS18B20 | 17 | P4 header carries GND/3V3/17/18 — one connector for the sensor |
+| Speaker BCLK / LRCLK / DIN | 42 / 2 / 41 | onboard amp wired to P7 `Speak` |
+
+Keep motor EN's disable-first behaviour (drive inactive at boot before
+enabling output mode).