Difference between revisions of "File:RPI open spi1.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:  

• 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