Unit LCD

SKU:U120

Description

Unit LCD is a 1.14 inch color LCD expansion screen unit. It adopts ST7789V2 drive scheme, the resolution is 135*240, and it supports RGB666 display (262,144 colors). The internal integration of ESP32-PICO control core (built-in firmware, display development is more convenient), support through I2C (addr: 0x3E) communication interface for control and firmware upgrades. The back of the screen is integrated with a magnetic design, which can easily adsorb the metal surface for fixing. The LCD screen extension is suitable for embedding in various instruments or control devices that need to display simple content as a display panel.

Product Features

• 1.14 inch color LCD display panel
• ST7789V2 drive scheme
• I2C communication interface
• 135*240 resolution
• Viewing angle: full viewing angle
• Magnetic back design
• Support I2C firmware upgrade

Include

• 1x Unit LCD
• 1x HY2.0-4P Cable

Applications

• Information display

Specification

PinMap

Schematic

Related Link

• Datasheet

  • ST7789V2

• Library

  • M5GFX Library

• Firmware

  • M5UnitLCD_FirmWare

Example

• Arduino

#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);
}

Video

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 colors that can be displayed is 262,144 colors of RGB666, which is the specification of ST7789V2.
• The ESP32 is in charge of I2C communication and draws in the frame buffer in memory based on the received contents.
• The contents of the frame buffer in the memory of the ESP32 are reflected in ST7789V2 by DMA transfer of SPI communication.
• It is represented by RGB888 16,777,216 colors on the frame buffer.

About Communication with Unit LCD

• You can send commands and receive data to the Unit LCD using I2C communication.
• The maximum communication speed of I2C communication is 400kHz.
• The initial value of the 7-bit address of I2C is 0x3E. It can be changed with the CHANGE_ADDR command.
• The required number of bytes to send depends on the command.
  Some commands complete in 1 Byte, while others require 7 Byte.
  There are also indefinite length commands that do not end until communication is stopped.
• If I2C communication STOP or RESTART occurs during command transmission, the interrupted command will not be processed.
  It must be transmitted uninterrupted to the end in a single transmission sequence.
• After sending a fixed-length command, you can send another command in succession.
• After sending an indefinite-length command, I2C communication must be stopped to indicate the end of the command.
• If you send a NOP command or an undefined command, the communication content is ignored until I2C communication stops.
• Since the I2C communication unit and the drawing processing unit operate in parallel, I2C communication can be performed even during the drawing processing.
• The I2C communication contents are stored in the command buffer on the ESP32 memory, and the drawing processing unit processes this sequentially.
• You should use the READ_BUFCOUNT command to check the remaining amount of the buffer , as sending a large amount of heavy processing, such as extensive fill or range copy, can overwhelm the command buffer.

About drawing commands

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

Command list

※ Undefined commands are treated as NOP.

Command list (readable commands)

Communication example

The command 6Ah is a total of 7Byte command sequence.
If an I2C communication STOP or RESTART occurs during transmission, the command will not be processed. It is necessary to transmit without interruption until the end in a single transmission sequence.

Any of the rectangle fill commands 68h to 6Ch can be used for rectangle fill. Indexes 1 through 4 are the same, but indexes 5 and onward have different methods for specifying colors.

The "remembered color" of command 68h means that the last specified color will be reused. In other words, if you want to do several rectangular fills of the same color in succession, you can specify the color only for the first rectangular fill and then omit the color specification by using the 68h command.

Command 6Ch, ARGB8888, allows you to specify an alpha channel (transparency), which allows you to combine the already drawn content with the drawing color.

• The RLE specification is based on the RLE for BMP files.
• Unlike RLE for BMP files, it can be used for RGB565 and RGB888.
• It first sends a consecutive number of pixels of the same color (0-255), followed by the color data.
• If 0 is sent to a consecutive number, it will be in direct mode without using RLE.
• In direct mode, the number of pixels (1-255) is sent first, followed by the color data for the number of pixels.

The above example will be handled as follows.

• index1-3 : Draw 7 pixels of red in RLE mode.
• index4-5 : Switch to direct mode and instruct it to draw 3 pixels.
• index6-11: Sends the color for 3 pixels in direct mode and draws green, blue, and red.
• Since the direct mode for 3 pixels is completed by index11, we will return to the RLE mode from index12.
• index12-14 : Draws 4 pixels of blue in RLE mode.

Firmware upgrade

Method 1. Use ESP32-Downloader to download firmware for update

Method 2. Update via I2C communication

Module Size