Boardlilygo

LILYGO T-Display-S3

LILYGO T-Display-S3: ESP32-S3 board with an on-board 170x320 ST7789 LCD on a parallel bus (BL 38, D0-D7 = 39/40/41/42/45/46/47/48, RST 5, CS 6, DC 7, WR 8, RD 9), touch INT 16 / RES 21, both 12-position headers fully mapped (P1/P2), and GPIO15 as the peripheral power control that must be HIGH on battery power.

Assembly & compatibility

Main chip: ESP32-S3

Revisions

Current family (base / Touch / MIDI variants) — One hardware family sold in three variants; v1 is an internal ordering id. · LILYGO T-Display-S3 repo (README pinout table, base/Touch/MIDI schematics, PlatformIO board def; commit 2025-10-13) · README.md#L19-L21

Pinout

power · ground · GPIO / signal · onboard LED

P1 header. Vendor pin diagram view: board back, USB down - P2 left, P1 right, both columns numbered 12-to-1 top-down. Rotate the board on the same face so USB points up: P1 moves to the left, numbered 1-to-12 top-down (12 pins)

Both readings are the same physical column seen after a same-face rotation; no mirroring involved · Source: LILYGO T-Display-S3 repo (README pinout table, base/Touch/MIDI schematics, PlatformIO board def; commit 2025-10-13) · schematic PDF at repo ref 1cc41eb1, net labels on the P1 header nets, cross-checked against the official board image T-DISPLAY-S3.jpg

No.	Name	Type	GPIO	Function
1	3V3	P		3.3 V output
2	GND	G		Ground
3	GND	G		Ground (silkscreen 'G')
4	NC	NC		Not connected
5	GPIO16	I/O	16	TP_INT net (touch interrupt)
6	GPIO21	I/O	21	TP_RESET net (touch reset)
7	GPIO17	I/O	17	I2C SCL (wire name; general GPIO)
8	GPIO18	I/O	18	I2C SDA (wire name; general GPIO)
9	GPIO44	I/O	44	U0RXD (UART0 fallback RX)
10	GPIO43	I/O	43	U0TXD (UART0 fallback TX)
11	GND	G		Ground
12	GND	G		Ground

P2 header. Vendor pin diagram view: board back, USB down - P2 left, P1 right, both columns numbered 12-to-1 top-down. Rotate the board on the same face so USB points up: P2 moves to the right, numbered 1-to-12 top-down (12 pins)

No.	Name	Type	GPIO	Function
1	5V	P		5 V input/output (USB or battery rail)
2	GND	G		Ground
3	NC	NC		Not connected
4	NC	NC		Not connected
5	GPIO13	I/O	13	Free header GPIO; SD_CMD on the SD Shield
6	GPIO12	I/O	12	Free header GPIO; SD_D0 on the SD Shield
7	GPIO11	I/O	11	Free header GPIO; SD_CLK on the SD Shield
8	GPIO10	I/O	10	Free header GPIO
9	GPIO3	I/O	3	Free header GPIO
10	GPIO2	I/O	2	Free header GPIO
11	GPIO1	I/O	1	Free header GPIO
12	3V3	P		3.3 V output

The T-Display-S3 is LILYGO's ESP32-S3 board with the display built in: a 170x320 ST7789 LCD driven over a parallel bus — backlight G38, data D0-D7 on G39/G40/G41/G42/G45/G46/G47/G48, RST G5, CS G6, DC G7, WR G8, RD G9 — plus capacitive touch (INT G16, RES G21). It is not an SPI display; fourteen GPIOs belong to the panel (backlight, eight data lines, RST, CS, DC, WR, RD).

The single most useful fact about this board: GPIO15 is the peripheral power control. On battery or 5V pin-header power you must set it OUTPUT/HIGH before anything else, or the LCD and other peripherals stay dark. Two more quirks: the battery voltage on GPIO4 (ADC) can only be read while USB is unplugged, and with USB CDC disabled the console falls back to GPIO43/44.

Both headers are fully mapped. In the vendor pin diagram (board back, USB down) P1 sits on the right with pin 1 at the bottom; rotate the board on the same face so USB points up and P1 is the left column, P2 the right, pin 1 at the top of both: P1 runs 1-to-12 top-down 3V3 / GND / GND (silkscreen G) / NC / G16 / G21 / G17 / G18 / G44 / G43 / GND / GND, and P2 runs 5V / GND / NC / NC / G13 / G12 / G11 / G10 / G3 / G2 / G1 / 3V3 — order rebuilt from the schematic's net labels and cross-checked against the official board image. G16/G21 carry the TP_INT/TP_RESET touch nets (free on variants without a touch controller), and G13/G12/G11 double as the SD_CMD/D0/CLK routings of the SD Shield add-on.

Per the README Supported Products table, base and Touch both use the ESP32-S3R8: 16 MB flash + 8 MB OPI PSRAM — the base board already ships with the 1.9-inch LCD, and the Touch only adds a CST capacitive touch layer, not memory (the earlier claim that the base board lacks PSRAM was wrong). A MIDI variant is sold on the LILYGO store and the repo carries SCH_MIDI_V1.1, but its spec cells in the Supported Products table are still empty, so only its existence is recorded. The SD pins above exist only with the SD Shield add-on: the standard board has no SD slot. This page renders the MCUID data record for the family.