An intelligent hardware device often requires a screen as an interactive entry. The larger the display is,, the more content of the display, and the requirement of the hardware system is higher. Simple intelligent hardware products can be used to reduce the cost by reducing the hardware performance requirements by using a small size display or a segment display.
Equipment external interface: VGA, DVI, HDMI
For large intelligent hardware devices, such as advertising machine, karaoke room, generally use the LCD TV on the existing market as the display. So the interface is also a common interface for TV, VGA, DVI, HDMI and so on. The main control terminal uses multi core ARM or x86 system, which is similar to the practice of connecting TV with the computer.
These interfaces and protocols are very standard. CPU can be directly used if it has its own interface. If not, it can also easily transform the chip to achieve the output of these interfaces.
General intelligent hardware products, only HDMI video output, few VGA interfaces, almost no DVI interface.
Device to internal interface: serial port and parallel port
Less than 2 inches of small size LCD screen, or Segment LCD display, shows less data, generally using low speed serial port, such as I2C, SPI, UART.
If the screen resolution is more than 320x240, use SPI, scraper speed will be relatively slow, so the high resolution screen without using low-speed serial port.
As for I2C and UART, the speed is slower than SPI, so it is generally used only to drive a segment display or a OLED screen under 1 inches.