LilyGO TTGO T-Display

The LilyGO TTGO T-Display board offer an integrated TFT color display and a USB-C type connector.

This board is not based on a ESP32 module but is using the ESP32-D0WD-Q6 processor directly.

TTGO T-Display

ESP32-D0WD-Q6 Processor (Dual core, 240Mhz processor)
Display: IPS ST7789V 1.14 Inch display, 135 * 240 pixels, 64k colors
3.7V battery charging circuit
Supply voltage: 3.3V DC or 5V DC
SRAM: 520KB
Flash memory: 4MByte in QIO Mode
PCB dimensions: 51.4 x 25.2mm
JST Connector: 2Pin 1.25mmx
USB: Type-C
USB-Bridge: CP2104 chip

Arduino Board Configuration

The board can be used with the following Arduino settings:

Package: esp32 by Espressif
Board: ESP32 Dev Module
JTAG Adapter: Disbled
PSRAM: Disbled
Partition Scheme: Default 4MB with spiffs (1.2MB APP/1.5MB SPIFFS)
CPU Frequency: 240MHz
Flash Mode: QIO
Flash Frequency: 80 MHz
Flash Size: 4MByte (32Mbit)
Upload Speed: 921600
Arduino Runs On: Core 1
Events Runs On: Core 1
Core Debug Level: None
Erase All Flash: Disabled

Display ST7789

The display is a IPS type TFT display using the ST7789 driver chip on the SPI bus. It is supported by the GFX Library for Arduino.

The chip supports a maximal display resolution of 240*320 pixels in 262k colors but this display only supports 135*240 pixels with 64k colors in RGB565 addressing.

Therefore the display offsets must be specified in the configuration.

See configuration in env.json below.

External Connectors

Some power and GPIO pins are available for external components:

    +-------------+
    |   T T G O   |
G   | +---------+ | 3V
G   | |    D    | | 36
21  | |    I    | | 37
22  | |    S    | | 38
17  | |    P    | | 39
2   | |    L    | | 32
15  | |    A    | | 33
13  | |    Y    | | 25
12  | |         | | 26
G   | |         | | 27
G   | |         | |  G
3V  | |         | | 5V
    | +---------+ |
    |             B-RST
    | B-2     B-1 |
    +-----USB-----+

Internal GPIO usages

Name	GPIO	Remarks
TFT_MISO		n/a
TFT_MOSI	19	usually MISO on Arduino Setups
TFT_SCLK	18	= Arduino Standard
TFT_CS	5
TFT_DC	16
TFT_RST	23
TFT_BL	4	TFT Backlight
ADC_IN	34	(Batt_ADC)
BUTTON1	35
BUTTON2	0
ADC Power	14

The TFT is not connected to the usual SPI pins. The data pin is attached to pin 19 that is usually used for SPI data input (MISO). As the SPI bus and all TFT connections are not available on the board pins so there will be no conflict.

The Backlight can be dimmed by using a GPIO 4 and can be used to adjust the brightness.

Example env.json Device Configuration

{
  "device": {
    "0": {
      "name": "tdisplay",
      "title": "T-Display",
      "description": "LilyGO TTGO T-Display",
      "safemode": "false",
      "button": 0,
      "homepage": "/index.htm"
    }
  },

  "ota": { "0": {} },

  "DisplayST7789": {
    "0": {
      "description": "ST7789 Display",
      "width": "135",
      "height": "240",

      "rotation": "180",
      "colOffset": "52",
      "rowOffset": "40",
      "ips": "true",

      "lightpin": "4",
 
      "spimosi": "19",
      "spiCLK": "18",
      "spics": "5",
      "spidc": "16",
    
      "spiRST": "23"
    }
  },

  "value": {
    "dim": {
      "title": "Display Backlight",
      "description": "Manual Backlight control",
      "min": "0",
      "max": "100",
      "value": "50",
      "onvalue": "DisplayST7789/0?brightness=$v"
    }
  }
}