LilyGo T-Deck is a development board based on the ESP32S3 microcontroller using XTENSA architecture.
This board features a maximum CPU frequency of 240 MHz and 16MB flash memory.
About LilyGo T-Deck
🚀 The LilyGo T-Deck is a versatile development device featuring an ESP32-S3FN16R8 dual-core processor with integrated Wi-Fi and Bluetooth 5 (LE). It boasts a 2.8-inch IPS LCD (320x240) touch screen, a mini keyboard, and a trackball, making it ideal for portable applications. ⚡
📡 With support for LoRa transceiver (SX1262) at various frequencies (433/868/915 MHz), it enables long-range communication for IoT projects. The device comes with 16MB Flash and 8MB PSRAM, providing ample memory for complex applications.
💾 Additional features include a microphone, speaker, and optional GPS module, enhancing its functionality for diverse use cases.
Where to Buy LilyGo T-Deck
Starting from
$60 per unit
Prices are subject to change. We earn from qualifying purchases as an Amazon Associate.
📋 Technical Specifications
Complete technical specification details for LilyGo T-Deck
🖥️ Display
🛰️ Connectivity
🧠 Microcontroller
✨ Features & Pins
LilyGo T-Deck Pinout Diagram
Complete pin reference for LilyGo T-Deck
The LilyGo T-Deck pinout offers multiple GPIOs with various functionalities:
IO1 to IO3: GPIO, Touch, ADC
IO10 to IO13: SPI interface (CS, D, CLK, Q)
IO16: ADC
IO17 and IO18: UART (TX, RX)
IO38 to IO48: LCD data lines and control signals
Additionally, power pins like 3V3, 5V, and GND are available for peripheral connections.
✅ Safe Pins to Use
These pins are safe for general GPIO usage without boot or system conflicts
💡 Why Are These Pins Safe?
⚠️ Pins to Avoid or Use with Caution
Reserved for critical functions. Misuse may cause boot failures, programming issues, or system conflicts.
Boot behavior & flash voltage
Low-level debugging interface
USB Serial/JTAG communication
Memory & PSRAM connections
Debugging & firmware uploads
| PIN | Label | Why Avoid | Type |
|---|---|---|---|
| IO3 | GPIO3 | Sampled at reset to select JTAG interface (USB Serial/JTAG controller vs. external pins). Improper use can disable external JTAG or alter debug interface. | 🛠️ Strapping |
| IO10 | FSPICS0 | Used to select the external flash chip. It is required for flash access and cannot be repurposed without losing flash connectivity | ⚡ Flash |
| IO11 | FSPID | Used as a data line for flash (and in-package PSRAM). It should not be used as GPIO when the flash/PSRAM is in use. | ⚡ Flash |
| IO12 | FSPICLK | Drives the flash (and PSRAM) clock. This critical signal must be reserved for memory and not used as general GPIO. | ⚡ Flash |
| IO13 | FSPIQ | Used as a data line for flash/PSRAM transfers. Not available for other uses when flash/PSRAM is connected. | ⚡ Flash |
| IO38 | FSPIWP | On flash-equipped chips, this pin is tied to the flash’s WP# (or D3) line. It should be avoided for other use, as it’s needed for flash operations. | ⚡ Flash |
| IO39 | MTCK (GPIO39) | Default JTAG debugging TCK pin. If JTAG is needed, this pin must be free; it may also be used internally for PSRAM chip select on certain modules, so avoid repurposing it. | 🪛 Other |
| IO40 | MTDO (GPIO40) | Default JTAG TDO output for debugging. Using it as GPIO will interfere with JTAG debugging functionality. | 🪛 Other |
| IO41 | MTDI (GPIO41) | Default JTAG TDI input for debugging. Should be reserved for JTAG or left unused if JTAG is to remain available. | 🪛 Other |
| IO42 | MTMS (GPIO42) | Default JTAG TMS signal for debugging. Using this pin for other purposes will disable the JTAG interface (unless JTAG is rerouted to USB). | 🪛 Other |
| IO45 | GPIO45 | Determines flash/PSRAM power voltage (3.3 V vs 1.8 V) at boot. Must match hardware configuration; using as GPIO can upset flash supply setting. | 🛠️ Strapping |
| IO46 | GPIO46 | Must be at a defined level during reset (with GPIO0) to select normal or download boot and UART/USB print mode. This pin is input-only (no output drive), so it should be left for its intended strapping function. | 🛠️ Strapping |
| IO47 | SPICLK_P | Used only on variants with Octal SPI interface (e.g. ESP32-S3R16V) as part of the differential clock pair. On such chips it operates at 1.8 V and is reserved for the high-speed octal SPI clock, not for general GPIO use. | ⚡ Flash |
| IO48 | SPICLK_N | Used only on variants with Octal SPI interface, as the negative leg of the differential clock&. On such chips it operates at 1.8 V; it should be avoided for GPIO to prevent conflicts with the octal flash/PSRAM clock. | ⚡ Flash |
| IO9 | FSPIHD | Connected to external flash (data/hold signal) on most modules. Not recommended for use as GPIO, since it must remain dedicated to flash communication. | ⚡ Flash |
| IO14 | FSPIWP | Connected to external flash (data/write-protect signal). Not recommended as GPIO because it’s reserved for flash operations. | ⚡ Flash |
| IO20 | USB_D+ | By default connected to the on-chip USB Serial/JTAG controller. Using it as general GPIO without reconfiguring IO MUX will interfere with USB functionality. | 🔌 USB |
Useful Links
Datasheets and resources for LilyGo T-Deck
LilyGo T-Deck Custom Pin Mapping
Pin configuration and GPIO mapping for LilyGo T-Deck
| Pin | Function | ESP Pin | I/O Type | Description |
|---|---|---|---|---|
| 1 | 3V3 | 3.3V | POWER OUTPUT | 3.3V power output |
| 2 | GND | GND | POWER GROUND | Ground connection |
| 3 | 5V | 5V | POWER INPUT | 5V power input for the board |
| 4 | IO1 | GPIO1 | BIDIRECTIONAL | GPIO, Touch, ADC |
| 5 | IO2 | GPIO2 | BIDIRECTIONAL | GPIO, Touch, ADC |
| 6 | IO3 | GPIO3 | BIDIRECTIONAL | GPIO, Touch, ADC |
| 7 | IO10 | SPI_CS | BIDIRECTIONAL | GPIO, SPI Chip Select |
| 8 | IO11 | SPI_D | BIDIRECTIONAL | GPIO, SPI Data |
| 9 | IO12 | SPI_CLK | BIDIRECTIONAL | GPIO, SPI Clock |
| 10 | IO13 | SPI_Q | BIDIRECTIONAL | GPIO, SPI Q |
| 11 | IO16 | ADC2_CH5 | BIDIRECTIONAL | GPIO, ADC |
| 12 | IO17 | U1_TXD | BIDIRECTIONAL | GPIO, UART TX |
| 13 | IO18 | U1_RXD | BIDIRECTIONAL | GPIO, UART RX |
| 14 | IO21 | GPIO21 | BIDIRECTIONAL | GPIO |
| 15 | IO38 | LCD_BL | OUTPUT | GPIO, LCD Backlight |
| 16 | IO39 | LCD_D0 | OUTPUT | GPIO, LCD Data 0 |
| 17 | IO40 | LCD_D1 | OUTPUT | GPIO, LCD Data 1 |
| 18 | IO41 | LCD_D2 | OUTPUT | GPIO, LCD Data 2 |
| 19 | IO42 | LCD_D3 | OUTPUT | GPIO, LCD Data 3 |
| 20 | IO45 | LCD_D4 | OUTPUT | GPIO, LCD Data 4 |
| 21 | IO46 | LCD_D5 | OUTPUT | GPIO, LCD Data 5 |
| 22 | IO47 | LCD_D6 | OUTPUT | GPIO, LCD Data 6 |
| 23 | IO48 | LCD_D7 | OUTPUT | GPIO, LCD Data 7 |
| 24 | IO5 | LCD_RES | OUTPUT | GPIO, LCD Reset |
| 25 | IO6 | LCD_CS | OUTPUT | GPIO, LCD Chip Select |
| 26 | IO7 | LCD_DC | OUTPUT | GPIO, LCD Data/Command |
| 27 | IO8 | LCD_WR | OUTPUT | GPIO, LCD Write |
| 28 | IO9 | LCD_RD | OUTPUT | GPIO, LCD Read |
| 29 | IO15 | LCD_POWER_ON | OUTPUT | GPIO, LCD Power Enable |
| 30 | IO4 | LCD_BAT_VOLT | INPUT | GPIO, Battery Voltage Sense |
| 31 | IO14 | BUTTON | INPUT | User Button |
| 32 | IO20 | MIC | INPUT | Microphone Input |
| 33 | IO22 | SPEAKER | OUTPUT | Speaker Output |
| 34 | IO23 | LOADER | OUTPUT | Flash Loader |
| 35 | IO24 | KEYBOARD | INPUT | Keyboard Input |
| 36 | IO25 | TRACKBALL | INPUT | Trackball Sensor |
| 37 | IO26 | GPS_RX | INPUT | GPS Module RX |
| 38 | IO27 | GPS_TX | OUTPUT | GPS Module TX |
| 39 | IO28 | LORA_CS | OUTPUT | LoRa Chip Select |
| 40 | IO29 | LORA_RST | OUTPUT | LoRa Reset |
| 41 | IO30 | LORA_IRQ | INPUT | LoRa Interrupt Request |
| 42 | IO31 | EXPANSION | BIDIRECTIONAL | Expansion GPIO |
| 43 | IO32 | EXTRA | BIDIRECTIONAL | Extra GPIO |
Pin Mappings
Complete pinout and GPIO mapping for LilyGo T-Deck
| Pin | Analog | Touch | PWM | Other |
|---|---|---|---|---|
| 0 | BUTTON_1 | |||
| 1 | A0 | T1 | PWM | |
| 2 | A1 | T2 | PWM | |
| 3 | A2 | T3 | PWM | |
| 4 | PWM | BAT_VOLT | ||
| 10 | A9 | T10 | PWM | SS |
| 11 | A10 | T11 | PWM | MOSI |
| 12 | A11 | T12 | PWM | SCK |
| 13 | A12 | T13 | PWM | MISO |
| 17 | A16 | PWM | SCL | |
| 18 | A17 | PWM | SDA | |
| 43 | PWM | TX | ||
| 44 | PWM | RX |
Default Tools & Configuration
Build and upload settings for LilyGo T-Deck
| Setting | Value |
|---|---|
| Bootloader tool | esptool_py |
| Uploader tool | esptool_py |
| Network uploader tool | esp_ota |
| Bootloader address | 0x0 |
| Flash mode | dio |
| Boot mode | qio |
| PSRAM type | opi |
| Maximum upload size | 3072 KB (3145728 bytes) |
| Maximum data size | 320 KB (327680 bytes) |
The LilyGo T-Deck uses esptool_py for uploads , esp_ota for OTA updates, and esptool_py bootloader at 0x0.
Flash mode: dio | Boot mode: qio | PSRAM: opi
Max sketch size: 3072 KB | Max data size: 320 KB
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