File: RPI open spi1.png

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RPI_open_spi1.png(800 × 341 pixels, file size: 117 KB, MIME type: image/png)

C codes

A brief analysis of underlying interfaces

We have carried out the low-level encapsulation, if you need to know the internal implementation can go to the corresponding directory to check ,for the reason that the hardware platform and the internal implementation are different

We can open DEV_Config.c(.h) to see definitions,which in the catalogue RaspberryPi\c\lib\Config

1.There are three ways for C to drive:BCM2835 library, WiringPi library and Dev library respectively
2.We use Dev library by default. If you need to use BCM2835 or WiringPi to drive the RaspberryPi\c\Makefile, open RaspberryPi\c\Makefile and modify lines 13-15 as follows:  

RPI open spi1.png

  • Interface selection:
#define USE_SPI_4W  1
#define USE_IIC     0
Note:Switch SPI/I2C directly modified here
  • Data type
#define UBYTE      uint8_t
#define UWORD      uint16_t
#define UDOUBLE    uint32_t
  • Module initialization and exit processing
void DEV_Module_Init(void);
void DEV_Module_Exit(void);
Note: here is some GPIO processing before and after using the LCD screen.
  • Write GPIO
void DEV_Digital_Write(UWORD Pin, UBYTE Value)
Parameter: UWORD Pin: GPIO Pin number
UBYTE Value: level to be output, 0 or 1
  • Read GPIO
UBYTE DEV_Digital_Read(UWORD Pin)
Parameter:UWORD Pin:GPIO Pin number
Return value: level of GPIO, 0 or 1
  • GPIO mode setting
void DEV_GPIO_Mode(UWORD Pin, UWORD Mode)
Parameters:UWORD Pin: GPIO Pin number
UWORD Mode: Mode, 0: input, 1: output

GUI simple analysis

For the screen, if you need to draw pictures, display Chinese and English characters, display pictures, etc., you can use the upper application to do.,and we provide some basic functions here about some graphics processing in the directory RaspberryPi\c\lib\GUI\GUI_Paint.c(.h).
RPI open spi2.png
RaspberryPi\c\lib\Fonts is a character font which GUI dependent in the directory. RPI open spi3.png

  • New Image Properties: Create a new image property, this property includes the image buffer name, width, height, flip Angle, color

File history

Click on a date/time to view the file as it appeared at that time.

current08:01, 17 January 2022Thumbnail for version as of 08:01, 17 January 2022800 × 341 (117 KB)Eng49 (talk | contribs)