Unit LCD

SKU:U120

Description

Unit LCD is a 1.14-inch color LCD expansion display unit. It uses the ST7789V2 driver solution with a resolution of 135 x 240 and supports RGB666 display (262,144 colors). It integrates an ESP32-PICO control core internally (with built-in firmware, making display development more convenient), and supports control and firmware upgrades via the I2C communication interface (addr: 0x3E). A magnetic attachment design is integrated on the back of the screen, allowing it to be easily fixed to metal surfaces. This LCD expansion display is suitable for embedding into various instruments or control devices that require simple content display as a display panel.

Features

• 1.14 inch color LCD display panel
• I2C communication interface
• Viewing angle: full viewing angle
• Rear magnetic attachment design
• Supports I2C firmware upgrade

Includes

• 1 x Unit LCD
• 1 x HY2.0-4P Grove Cable (20cm)

Applications

• Information display screen

Specifications

Schematics

PinMap

Unit LCD

Model Size

Datasheets

• ST7789V2

Softwares

Arduino

• M5GFX Arduino Driver Library

#include <M5UnitLCD.h>

M5UnitLCD display;

M5Canvas canvas(&display);

static constexpr char text[] = "Hello world ! こんにちは世界！ this is long long string sample. 寿限無、寿限無、五劫の擦り切れ、海砂利水魚の、水行末・雲来末・風来末、喰う寝る処に住む処、藪ら柑子の藪柑子、パイポ・パイポ・パイポのシューリンガン、シューリンガンのグーリンダイ、グーリンダイのポンポコピーのポンポコナの、長久命の長助";
static constexpr size_t textlen = sizeof(text) / sizeof(text[0]);
int textpos = 0;
int scrollstep = 2;

void setup(void)
{
  display.init();
  display.setRotation(2);
  canvas.setColorDepth(1); // mono color
  canvas.setFont(&fonts::lgfxJapanMinchoP_32);
  canvas.setTextWrap(false);
  canvas.setTextSize(2);
  canvas.createSprite(display.width() + 64, 72);
}

void loop(void)
{
  int32_t cursor_x = canvas.getCursorX()-scrollstep;
  if (cursor_x <= 0)
  {
    textpos = 0;
    cursor_x = display.width();
  }

  canvas.setCursor(cursor_x, 0);
  canvas.scroll(-scrollstep, 0);
  while (textpos < textlen && cursor_x <= display.width())
  {
    canvas.print(text[textpos++]);
    cursor_x = canvas.getCursorX();
  }
  display.waitDisplay();
  canvas.pushSprite(&display, 0, (display.height()-canvas.height()) >> 1);
}

Internal Firmware

• Unit LCD Internal Firmware

Protocol

About Unit LCD

• Unit LCD is an I2C unit with ESP32 and ST7789V2.
• It has an IPS panel with a resolution of 135 x 240.
• The number of displayable colors is 262,144 in RGB666, which is a specification of the ST7789V2.
• ESP32 handles I2C communication and draws the framebuffer in memory based on received content.
• The frame buffer content in ESP32 memory is reflected on the ST7789V2 via SPI DMA transfer.
• It is represented by RGB888 16,777,216 colors on the framebuffer.

About I2C Communication

• You can send commands to the Unit LCD and receive data using I2C communication.
• The maximum I2C communication speed is 400kHz.
• The initial value of the I2C 7-bit address is 0x3E, and it can be changed using the CHANGE_ADDR command.
• The number of bytes to send depends on the command. Some commands complete within 1 byte, while others require 7 bytes. There are also variable-length commands that continue until communication stops.
• If an I2C communication STOP or RESTART occurs during command transmission, the interrupted command will not be processed. It must be transmitted continuously to the end in a single transmission sequence.
• After sending a fixed-length command, another command can be sent consecutively.
• After sending a variable-length command, I2C communication must be stopped to indicate the end of the command.
• If a NOP command or an undefined command is sent, the communication content will be ignored until I2C communication stops.
• Since the I2C communication unit and the drawing processing unit operate in parallel, I2C communication can be executed even during drawing processing.
• I2C communication content is stored in the command buffer in ESP32 memory and processed sequentially by the drawing processing unit.
• You should use the READ_BUFCOUNT command to check the remaining buffer capacity, as sending a large amount of heavy processing such as extensive fills or range copies may overflow the buffer.

About Drawing

• You can draw rectangles by filling any area with a single color using FILLRECT.
• If you want to draw just one pixel, you can use DRAWPIXEL instead of FILLRECT.
• If you use a command that omits the foreground color, the last used color will be applied.
• You can specify the drawing range using CASET and RASET, and send image data using the WRITE_RAW command.
• You can use WRITE_RLE instead of WRITE_RAW to send run-length encoded image data.

Command List

※ Undefined commands are treated as no-operation instructions.

Command List (Readable Commands)

Firmware Upgrade

• Method 1. Use ESP32-Downloader to update firmware

• Method 2. Update via I2C communication

UiFlow1

• Unit LCD UiFlow1 Documentation

UiFlow2

• Unit LCD UiFlow2 Documentation

Video

• UiFlow2 Unit LCD