AutoFilm-ESP32/docs/JC4827W543_PIN_AUDIT.md

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.