youyeetoo 0.71inch Double Eye Round LCD Display Module, 160×160 Resolution, SPI Interface, 65K Colors, Perfect for Creative Displays

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Specifications

Pinout Definition

Operating Principle

• LCD and its Controller
  • This LCD uses the built-in GC9D01 driver, with a resolution of 160×160. It has an internal GRAM and supports 12/16/18-bit data bus MCU interfaces, i.e., RGB444, RGB565, RGB666 three color formats, which are common RGB formats.
  • For most LCD controllers, the communication interface can be configured, including 8080 parallel, 3-wire SPI, 4-wire SPI, etc. This LCD uses a 4-wire SPI interface, which saves GPIO pins and increases communication speed.

• • Note: The difference from the traditional SPI protocol is that the data line sent from the slave to the host is hidden because it only needs to be displayed.
  • RESX is the reset pin, it is pulled low when the module is powered on, usually set to 1;
    
  • CSX is the slave chip select pin, and the chip is enabled only when CS is low;
    
  • D/CX is the data/command control pin of the chip, when DC = 0 a command is written; when DC = 1, data is written
    SDA is the data transmitted data, that is, RGB data;
    
  • SCL is the SPI communication clock pin.
    
  • For SPI communication, the data transmission has timing sequences involving clock phase (CPHA) and clock polarity (CPOL):
    
  • CPHA determines whether data is captured on the first or second clock edge. When CPHA = 0, data is captured on the first clock edge.
    
  • CPOL determines the idle level of the clock; CPOL = 0 means low.
    
  • From the diagram, it can be seen that when SCLK falls on the first edge, data transmission starts. One clock cycle transmits 8 bits, using SPI0, bitwise transmission, high bit first, and low bit last.