不按套路出牌,這么來寫IIC驅(qū)動(dòng)?
前言
前面分享了:干貨 | C語(yǔ)言實(shí)現(xiàn)面向?qū)ο缶幊蹋ǜ酱a),分享了一些概念及基礎(chǔ)例子。這不,給大家找來了嵌入式中的編程實(shí)例:C語(yǔ)言使用面向?qū)ο髮?shí)現(xiàn)IIC驅(qū)動(dòng)。
一.簡(jiǎn)述
使用面向?qū)ο蟮木幊趟枷敕庋bIIC驅(qū)動(dòng),將IIC的屬性和操作封裝成一個(gè)庫(kù),在需要?jiǎng)?chuàng)建一個(gè)IIC設(shè)備時(shí)只需要實(shí)例化一個(gè)IIC對(duì)象即可,本文是基于STM32和HAL庫(kù)做進(jìn)一步封裝的。
底層驅(qū)動(dòng)方法不重要,封裝的思想很重要。在完成對(duì)IIC驅(qū)動(dòng)的封裝之后借助繼承特性實(shí)現(xiàn)AT24C64存儲(chǔ)器的驅(qū)動(dòng)開發(fā),仍使用面向?qū)ο蟮乃枷敕庋bAT24C64驅(qū)動(dòng)。
二.IIC驅(qū)動(dòng)面向?qū)ο蠓庋b
iic.h頭文件主要是類模板的定義,具體如下:
//定義IIC類 typedef struct IIC_Type { //屬性 GPIO_TypeDef *GPIOx_SCL; //GPIO_SCL所屬的GPIO組(如:GPIOA) GPIO_TypeDef *GPIOx_SDA; //GPIO_SDA所屬的GPIO組(如:GPIOA) uint32_t GPIO_SCL; //GPIO_SCL的IO引腳(如:GPIO_PIN_0) uint32_t GPIO_SDA; //GPIO_SDA的IO引腳(如:GPIO_PIN_0) //操作 void (*IIC_Init)(const struct IIC_Type*); //IIC_Init void (*IIC_Start)(const struct IIC_Type*); //IIC_Start void (*IIC_Stop)(const struct IIC_Type*); //IIC_Stop uint8_t (*IIC_Wait_Ack)(const struct IIC_Type*); //IIC_Wait_ack,返回wait失敗或是成功 void (*IIC_Ack)(const struct IIC_Type*); //IIC_Ack,IIC發(fā)送ACK信號(hào) void (*IIC_NAck)(const struct IIC_Type*); //IIC_NAck,IIC發(fā)送NACK信號(hào) void (*IIC_Send_Byte)(const struct IIC_Type*,uint8_t); //IIC_Send_Byte,入口參數(shù)為要發(fā)送的字節(jié) uint8_t (*IIC_Read_Byte)(const struct IIC_Type*,uint8_t); //IIC_Send_Byte,入口參數(shù)為是否要發(fā)送ACK信號(hào) void (*delay_us)(uint32_t); //us延時(shí) }IIC_TypeDef;
iic.c源文件主要是類模板具體操作函數(shù)的實(shí)現(xiàn),具體如下:
//設(shè)置SDA為輸入模式 static void SDA_IN(const struct IIC_Type* IIC_Type_t) { uint8_t io_num = 0; //定義io Num號(hào) switch(IIC_Type_t->GPIO_SDA)
{ case GPIO_PIN_0:
io_num = 0; break; case GPIO_PIN_1:
io_num = 1; break; case GPIO_PIN_2:
io_num = 2; break; case GPIO_PIN_3:
io_num = 3; break; case GPIO_PIN_4:
io_num = 4; break; case GPIO_PIN_5:
io_num = 5; break; case GPIO_PIN_6:
io_num = 6; break; case GPIO_PIN_7:
io_num = 7; break; case GPIO_PIN_8:
io_num = 8; break; case GPIO_PIN_9:
io_num = 9; break; case GPIO_PIN_10:
io_num = 10; break; case GPIO_PIN_11:
io_num = 11; break; case GPIO_PIN_12:
io_num = 12; break; case GPIO_PIN_13:
io_num = 13; break; case GPIO_PIN_14:
io_num = 14; break; case GPIO_PIN_15:
io_num = 15; break;
}
IIC_Type_t->GPIOx_SDA->MODER&=~(3<<(io_num*2)); //將GPIOx_SDA->GPIO_SDA清零 IIC_Type_t->GPIOx_SDA->MODER|=0<<(io_num*2); //將GPIOx_SDA->GPIO_SDA設(shè)置為輸入模式 } //設(shè)置SDA為輸出模式 static void SDA_OUT(const struct IIC_Type* IIC_Type_t) { uint8_t io_num = 0; //定義io Num號(hào) switch(IIC_Type_t->GPIO_SDA)
{ case GPIO_PIN_0:
io_num = 0; break; case GPIO_PIN_1:
io_num = 1; break; case GPIO_PIN_2:
io_num = 2; break; case GPIO_PIN_3:
io_num = 3; break; case GPIO_PIN_4:
io_num = 4; break; case GPIO_PIN_5:
io_num = 5; break; case GPIO_PIN_6:
io_num = 6; break; case GPIO_PIN_7:
io_num = 7; break; case GPIO_PIN_8:
io_num = 8; break; case GPIO_PIN_9:
io_num = 9; break; case GPIO_PIN_10:
io_num = 10; break; case GPIO_PIN_11:
io_num = 11; break; case GPIO_PIN_12:
io_num = 12; break; case GPIO_PIN_13:
io_num = 13; break; case GPIO_PIN_14:
io_num = 14; break; case GPIO_PIN_15:
io_num = 15; break;
}
IIC_Type_t->GPIOx_SDA->MODER&=~(3<<(io_num*2)); //將GPIOx_SDA->GPIO_SDA清零 IIC_Type_t->GPIOx_SDA->MODER|=1<<(io_num*2); //將GPIOx_SDA->GPIO_SDA設(shè)置為輸出模式 } //設(shè)置SCL電平 static void IIC_SCL(const struct IIC_Type* IIC_Type_t,int n) { if(n == 1)
{
HAL_GPIO_WritePin(IIC_Type_t->GPIOx_SCL,IIC_Type_t->GPIO_SCL,GPIO_PIN_SET); //設(shè)置SCL為高電平 } else{
HAL_GPIO_WritePin(IIC_Type_t->GPIOx_SCL,IIC_Type_t->GPIO_SCL,GPIO_PIN_RESET); //設(shè)置SCL為低電平 }
} //設(shè)置SDA電平 static void IIC_SDA(const struct IIC_Type* IIC_Type_t,int n) { if(n == 1)
{
HAL_GPIO_WritePin(IIC_Type_t->GPIOx_SDA,IIC_Type_t->GPIO_SDA,GPIO_PIN_SET); //設(shè)置SDA為高電平 } else{
HAL_GPIO_WritePin(IIC_Type_t->GPIOx_SDA,IIC_Type_t->GPIO_SDA,GPIO_PIN_RESET); //設(shè)置SDA為低電平 }
} //讀取SDA電平 static uint8_t READ_SDA(const struct IIC_Type* IIC_Type_t) { return HAL_GPIO_ReadPin(IIC_Type_t->GPIOx_SDA,IIC_Type_t->GPIO_SDA); //讀取SDA電平 } //IIC初始化 static void IIC_Init_t(const struct IIC_Type* IIC_Type_t) {
GPIO_InitTypeDef GPIO_Initure; //根據(jù)GPIO組初始化GPIO時(shí)鐘 if(IIC_Type_t->GPIOx_SCL == GPIOA || IIC_Type_t->GPIOx_SDA == GPIOA)
{
__HAL_RCC_GPIOA_CLK_ENABLE(); //使能GPIOA時(shí)鐘 } if(IIC_Type_t->GPIOx_SCL == GPIOB || IIC_Type_t->GPIOx_SDA == GPIOB)
{
__HAL_RCC_GPIOB_CLK_ENABLE(); //使能GPIOB時(shí)鐘 } if(IIC_Type_t->GPIOx_SCL == GPIOC || IIC_Type_t->GPIOx_SDA == GPIOC)
{
__HAL_RCC_GPIOC_CLK_ENABLE(); //使能GPIOC時(shí)鐘 } if(IIC_Type_t->GPIOx_SCL == GPIOD || IIC_Type_t->GPIOx_SDA == GPIOD)
{
__HAL_RCC_GPIOD_CLK_ENABLE(); //使能GPIOD時(shí)鐘 } if(IIC_Type_t->GPIOx_SCL == GPIOE || IIC_Type_t->GPIOx_SDA == GPIOE)
{
__HAL_RCC_GPIOE_CLK_ENABLE(); //使能GPIOE時(shí)鐘 } if(IIC_Type_t->GPIOx_SCL == GPIOH || IIC_Type_t->GPIOx_SDA == GPIOH)
{
__HAL_RCC_GPIOH_CLK_ENABLE(); //使能GPIOH時(shí)鐘 } //GPIO_SCL初始化設(shè)置 GPIO_Initure.Pin=IIC_Type_t->GPIO_SCL;
GPIO_Initure.Mode=GPIO_MODE_OUTPUT_PP; //推挽輸出 GPIO_Initure.Pull=GPIO_PULLUP; //上拉 GPIO_Initure.Speed=GPIO_SPEED_FREQ_VERY_HIGH; //快速 HAL_GPIO_Init(IIC_Type_t->GPIOx_SCL,&GPIO_Initure); //GPIO_SDA初始化設(shè)置 GPIO_Initure.Pin=IIC_Type_t->GPIO_SDA;
GPIO_Initure.Mode=GPIO_MODE_OUTPUT_PP; //推挽輸出 GPIO_Initure.Pull=GPIO_PULLUP; //上拉 GPIO_Initure.Speed=GPIO_SPEED_FREQ_VERY_HIGH; //快速 HAL_GPIO_Init(IIC_Type_t->GPIOx_SDA,&GPIO_Initure); //SCL與SDA的初始化均為高電平 IIC_SCL(IIC_Type_t,1);
IIC_SDA(IIC_Type_t,1);
} //IIC Start static void IIC_Start_t(const struct IIC_Type* IIC_Type_t) {
SDA_OUT(IIC_Type_t); //sda線輸出 IIC_SDA(IIC_Type_t,1);
IIC_SCL(IIC_Type_t,1);
IIC_Type_t->delay_us(4);
IIC_SDA(IIC_Type_t,0); //START:when CLK is high,DATA change form high to low IIC_Type_t->delay_us(4);
IIC_SCL(IIC_Type_t,0); //鉗住I2C總線,準(zhǔn)備發(fā)送或接收數(shù)據(jù) } //IIC Stop static void IIC_Stop_t(const struct IIC_Type* IIC_Type_t) {
SDA_OUT(IIC_Type_t); //sda線輸出 IIC_SCL(IIC_Type_t,0);
IIC_SDA(IIC_Type_t,0); //STOP:when CLK is high DATA change form low to high IIC_Type_t->delay_us(4);
IIC_SCL(IIC_Type_t,1);
IIC_SDA(IIC_Type_t,1); //發(fā)送I2C總線結(jié)束信號(hào) IIC_Type_t->delay_us(4);
} //IIC_Wait_ack 返回HAL_OK表示wait成功,返回HAL_ERROR表示wait失敗 static uint8_t IIC_Wait_Ack_t(const struct IIC_Type* IIC_Type_t) //IIC_Wait_ack,返回wait失敗或是成功 { uint8_t ucErrTime = 0;
SDA_IN(IIC_Type_t); //SDA設(shè)置為輸入 IIC_SDA(IIC_Type_t,1);IIC_Type_t->delay_us(1);
IIC_SCL(IIC_Type_t,1);IIC_Type_t->delay_us(1); while(READ_SDA(IIC_Type_t))
{
ucErrTime++; if(ucErrTime>250)
{
IIC_Type_t->IIC_Stop(IIC_Type_t); return HAL_ERROR;
}
}
IIC_SCL(IIC_Type_t,0);//時(shí)鐘輸出0 return HAL_OK;
} //產(chǎn)生ACK應(yīng)答 static void IIC_Ack_t(const struct IIC_Type* IIC_Type_t) {
IIC_SCL(IIC_Type_t,0);
SDA_OUT(IIC_Type_t);
IIC_SDA(IIC_Type_t,0);
IIC_Type_t->delay_us(2);
IIC_SCL(IIC_Type_t,1);
IIC_Type_t->delay_us(2);
IIC_SCL(IIC_Type_t,0);
} //產(chǎn)生NACK應(yīng)答 static void IIC_NAck_t(const struct IIC_Type* IIC_Type_t) {
IIC_SCL(IIC_Type_t,0);
SDA_OUT(IIC_Type_t);
IIC_SDA(IIC_Type_t,1);
IIC_Type_t->delay_us(2);
IIC_SCL(IIC_Type_t,1);
IIC_Type_t->delay_us(2);
IIC_SCL(IIC_Type_t,0);
} //IIC_Send_Byte,入口參數(shù)為要發(fā)送的字節(jié) static void IIC_Send_Byte_t(const struct IIC_Type* IIC_Type_t,uint8_t txd) { uint8_t t = 0;
SDA_OUT(IIC_Type_t);
IIC_SCL(IIC_Type_t,0);//拉低時(shí)鐘開始數(shù)據(jù)傳輸 for(t=0;t<8;t++)
{
IIC_SDA(IIC_Type_t,(txd&0x80)>>7);
txd <<= 1;
IIC_Type_t->delay_us(2); //對(duì)TEA5767這三個(gè)延時(shí)都是必須的 IIC_SCL(IIC_Type_t,1);
IIC_Type_t->delay_us(2);
IIC_SCL(IIC_Type_t,0);
IIC_Type_t->delay_us(2);
}
} //IIC_Send_Byte,入口參數(shù)為是否要發(fā)送ACK信號(hào) static uint8_t IIC_Read_Byte_t(const struct IIC_Type* IIC_Type_t,uint8_t ack) { uint8_t i,receive = 0;
SDA_IN(IIC_Type_t);//SDA設(shè)置為輸入 for(i=0;i<8;i++ )
{
IIC_SCL(IIC_Type_t,0);
IIC_Type_t->delay_us(2);
IIC_SCL(IIC_Type_t,1);
receive<<=1; if(READ_SDA(IIC_Type_t))receive++;
IIC_Type_t->delay_us(1);
} if (!ack)
IIC_Type_t->IIC_NAck(IIC_Type_t);//發(fā)送nACK else IIC_Type_t->IIC_Ack(IIC_Type_t); //發(fā)送ACK return receive;
} //實(shí)例化一個(gè)IIC1外設(shè),相當(dāng)于一個(gè)結(jié)構(gòu)體變量,可以直接在其他文件中使用 IIC_TypeDef IIC1 = {
.GPIOx_SCL = GPIOA, //GPIO組為GPIOA .GPIOx_SDA = GPIOA, //GPIO組為GPIOA .GPIO_SCL = GPIO_PIN_5, //GPIO為PIN5 .GPIO_SDA = GPIO_PIN_6, //GPIO為PIN6 .IIC_Init = IIC_Init_t,
.IIC_Start = IIC_Start_t,
.IIC_Stop = IIC_Stop_t,
.IIC_Wait_Ack = IIC_Wait_Ack_t,
.IIC_Ack = IIC_Ack_t,
.IIC_NAck = IIC_NAck_t,
.IIC_Send_Byte = IIC_Send_Byte_t,
.IIC_Read_Byte = IIC_Read_Byte_t,
.delay_us = delay_us //需自己外部實(shí)現(xiàn)delay_us函數(shù) };
上述就是IIC驅(qū)動(dòng)的封裝,由于沒有應(yīng)用場(chǎng)景暫不測(cè)試其實(shí)用性,待下面ATC64的驅(qū)動(dòng)縫縫扎黃寫完之后一起測(cè)試使用。
三.ATC64XX驅(qū)動(dòng)封裝實(shí)現(xiàn)
at24cxx.h頭文件主要是類模板的定義,具體如下:
// 以下是共定義個(gè)具體容量存儲(chǔ)器的容量 #define AT24C01 127 #define AT24C02 255 #define AT24C04 511 #define AT24C08 1023 #define AT24C16 2047 #define AT24C32 4095 #define AT24C64 8191 //8KBytes #define AT24C128 16383 #define AT24C256 32767 //定義AT24CXX類 typedef struct AT24CXX_Type { //屬性 u32 EEP_TYPE; //存儲(chǔ)器類型(存儲(chǔ)器容量) //操作 IIC_TypeDef IIC; //IIC驅(qū)動(dòng) uint8_t (*AT24CXX_ReadOneByte)(const struct AT24CXX_Type*,uint16_t); //指定地址讀取一個(gè)字節(jié) void (*AT24CXX_WriteOneByte)(const struct AT24CXX_Type*,uint16_t,uint8_t); //指定地址寫入一個(gè)字節(jié) void (*AT24CXX_WriteLenByte)(uint16_t,uint32_t,uint8_t); //指定地址開始寫入指定長(zhǎng)度的數(shù)據(jù) uint32_t (*AT24CXX_ReadLenByte)(uint16_t,uint8_t); //指定地址開始讀取指定長(zhǎng)度數(shù)據(jù) void (*AT24CXX_Write)(uint16_t,uint8_t *,uint16_t); //指定地址開始寫入指定長(zhǎng)度的數(shù)據(jù) void (*AT24CXX_Read)(uint16_t,uint8_t *,uint16_t); //指定地址開始寫入指定長(zhǎng)度的數(shù)據(jù) void (*AT24CXX_Init)(const struct AT24CXX_Type*); //初始化IIC uint8_t (*AT24CXX_Check)(const struct AT24CXX_Type*); //檢查器件 }AT24CXX_TypeDef; extern AT24CXX_TypeDef AT24C_64; //外部聲明實(shí)例化AT24CXX對(duì)象
at24cxx.c源文件主要是類模板具體操作函數(shù)的實(shí)現(xiàn),具體如下:
//在AT24CXX指定地址讀出一個(gè)數(shù)據(jù) //ReadAddr:開始讀數(shù)的地址 //返回值 :讀到的數(shù)據(jù) static uint8_t AT24CXX_ReadOneByte_t(const struct AT24CXX_Type* AT24CXX_Type_t,uint16_t ReadAddr) { uint8_t temp=0;
AT24CXX_Type_t->IIC.IIC_Start(&AT24CXX_Type_t->IIC); //根據(jù)AT的型號(hào)發(fā)送不同的地址 if(AT24CXX_Type_t->EEP_TYPE > AT24C16)
{
AT24CXX_Type_t->IIC.IIC_Send_Byte(&AT24CXX_Type_t->IIC,0XA0); //發(fā)送寫命令 AT24CXX_Type_t->IIC.IIC_Wait_Ack(&AT24CXX_Type_t->IIC);
AT24CXX_Type_t->IIC.IIC_Send_Byte(&AT24CXX_Type_t->IIC,ReadAddr>>8);//發(fā)送高地址 }else AT24CXX_Type_t->IIC.IIC_Send_Byte(&AT24CXX_Type_t->IIC,0XA0+((ReadAddr/256)<<1)); //發(fā)送器件地址0XA0,寫數(shù)據(jù) AT24CXX_Type_t->IIC.IIC_Wait_Ack(&AT24CXX_Type_t->IIC);
AT24CXX_Type_t->IIC.IIC_Send_Byte(&AT24CXX_Type_t->IIC,ReadAddr%256); //發(fā)送低地址 AT24CXX_Type_t->IIC.IIC_Wait_Ack(&AT24CXX_Type_t->IIC);
AT24CXX_Type_t->IIC.IIC_Start(&AT24CXX_Type_t->IIC);
AT24CXX_Type_t->IIC.IIC_Send_Byte(&AT24CXX_Type_t->IIC,0XA1); //進(jìn)入接收模式 AT24CXX_Type_t->IIC.IIC_Wait_Ack(&AT24CXX_Type_t->IIC);
temp=AT24CXX_Type_t->IIC.IIC_Read_Byte(&AT24CXX_Type_t->IIC,0);
AT24CXX_Type_t->IIC.IIC_Stop(&AT24CXX_Type_t->IIC);//產(chǎn)生一個(gè)停止條件 return temp;
} //在AT24CXX指定地址寫入一個(gè)數(shù)據(jù) //WriteAddr :寫入數(shù)據(jù)的目的地址 //DataToWrite:要寫入的數(shù)據(jù) static void AT24CXX_WriteOneByte_t(const struct AT24CXX_Type* AT24CXX_Type_t,uint16_t WriteAddr,uint8_t DataToWrite) {
AT24CXX_Type_t->IIC.IIC_Start(&AT24CXX_Type_t->IIC); if(AT24CXX_Type_t->EEP_TYPE > AT24C16)
{
AT24CXX_Type_t->IIC.IIC_Send_Byte(&AT24CXX_Type_t->IIC,0XA0); //發(fā)送寫命令 AT24CXX_Type_t->IIC.IIC_Wait_Ack(&AT24CXX_Type_t->IIC);
AT24CXX_Type_t->IIC.IIC_Send_Byte(&AT24CXX_Type_t->IIC,WriteAddr>>8);//發(fā)送高地址 }else AT24CXX_Type_t->IIC.IIC_Send_Byte(&AT24CXX_Type_t->IIC,0XA0+((WriteAddr/256)<<1)); //發(fā)送器件地址0XA0,寫數(shù)據(jù) AT24CXX_Type_t->IIC.IIC_Wait_Ack(&AT24CXX_Type_t->IIC);
AT24CXX_Type_t->IIC.IIC_Send_Byte(&AT24CXX_Type_t->IIC,WriteAddr%256); //發(fā)送低地址 AT24CXX_Type_t->IIC.IIC_Wait_Ack(&AT24CXX_Type_t->IIC);
AT24CXX_Type_t->IIC.IIC_Send_Byte(&AT24CXX_Type_t->IIC,DataToWrite); //發(fā)送字節(jié) AT24CXX_Type_t->IIC.IIC_Wait_Ack(&AT24CXX_Type_t->IIC);
AT24CXX_Type_t->IIC.IIC_Stop(&AT24CXX_Type_t->IIC);//產(chǎn)生一個(gè)停止條件 AT24CXX_Type_t->IIC.delay_us(10000);
} //在AT24CXX里面的指定地址開始寫入長(zhǎng)度為L(zhǎng)en的數(shù)據(jù) //該函數(shù)用于寫入16bit或者32bit的數(shù)據(jù). //WriteAddr :開始寫入的地址 //DataToWrite:數(shù)據(jù)數(shù)組首地址 //Len :要寫入數(shù)據(jù)的長(zhǎng)度2,4 static void AT24CXX_WriteLenByte_t(uint16_t WriteAddr,uint32_t DataToWrite,uint8_t Len) { uint8_t t; for(t=0;t>(8*t))&0xff);
}
} //在AT24CXX里面的指定地址開始讀出長(zhǎng)度為L(zhǎng)en的數(shù)據(jù) //該函數(shù)用于讀出16bit或者32bit的數(shù)據(jù). //ReadAddr :開始讀出的地址 //返回值 :數(shù)據(jù) //Len :要讀出數(shù)據(jù)的長(zhǎng)度2,4 static uint32_t AT24CXX_ReadLenByte_t(uint16_t ReadAddr,uint8_t Len) { uint8_t t; uint32_t temp=0; for(t=0;t8;
temp+=AT24CXX_ReadOneByte(ReadAddr+Len-t-1);
} return temp;
} //在AT24CXX里面的指定地址開始寫入指定個(gè)數(shù)的數(shù)據(jù) //WriteAddr :開始寫入的地址 對(duì)24c64為0~8191 //pBuffer :數(shù)據(jù)數(shù)組首地址 //NumToWrite:要寫入數(shù)據(jù)的個(gè)數(shù) static void AT24CXX_Write_t(uint16_t WriteAddr,uint8_t *pBuffer,uint16_t NumToWrite) { while(NumToWrite--)
{
AT24CXX_WriteOneByte(WriteAddr,*pBuffer);
WriteAddr++;
pBuffer++;
}
} //在AT24CXX里面的指定地址開始讀出指定個(gè)數(shù)的數(shù)據(jù) //ReadAddr :開始讀出的地址 對(duì)24c64為0~8191 //pBuffer :數(shù)據(jù)數(shù)組首地址 //NumToRead:要讀出數(shù)據(jù)的個(gè)數(shù) static void AT24CXX_Read_t(uint16_t ReadAddr,uint8_t *pBuffer,uint16_t NumToRead) { while(NumToRead)
{
*pBuffer++=AT24CXX_ReadOneByte(ReadAddr++);
NumToRead--;
}
} //初始化IIC接口 static void AT24CXX_Init_t(const struct AT24CXX_Type* AT24CXX_Type_t) {
AT24CXX_Type_t->IIC.IIC_Init(&AT24CXX_Type_t->IIC);//IIC初始化 } //檢查器件,返回0表示檢測(cè)成功,返回1表示檢測(cè)失敗 static uint8_t AT24CXX_Check_t(const struct AT24CXX_Type* AT24CXX_Type_t) { uint8_t temp;
temp = AT24CXX_Type_t->AT24CXX_ReadOneByte(AT24CXX_Type_t,AT24CXX_Type_t->EEP_TYPE);//避免每次開機(jī)都寫AT24CXX if(temp == 0X33)return 0; else//排除第一次初始化的情況 {
AT24CXX_Type_t->AT24CXX_WriteOneByte(AT24CXX_Type_t,AT24CXX_Type_t->EEP_TYPE,0X33);
temp = AT24CXX_Type_t->AT24CXX_ReadOneByte(AT24CXX_Type_t,AT24CXX_Type_t->EEP_TYPE); if(temp==0X33)return 0;
} return 1;
} //實(shí)例化AT24CXX對(duì)象 AT24CXX_TypeDef AT24C_64={
.EEP_TYPE = AT24C64, //存儲(chǔ)器類型(存儲(chǔ)器容量) //操作 .IIC={
.GPIOx_SCL = GPIOA,
.GPIOx_SDA = GPIOA,
.GPIO_SCL = GPIO_PIN_5,
.GPIO_SDA = GPIO_PIN_6,
.IIC_Init = IIC_Init_t,
.IIC_Start = IIC_Start_t,
.IIC_Stop = IIC_Stop_t,
.IIC_Wait_Ack = IIC_Wait_Ack_t,
.IIC_Ack = IIC_Ack_t,
.IIC_NAck = IIC_NAck_t,
.IIC_Send_Byte = IIC_Send_Byte_t,
.IIC_Read_Byte = IIC_Read_Byte_t,
.delay_us = delay_us
}, //IIC驅(qū)動(dòng) .AT24CXX_ReadOneByte = AT24CXX_ReadOneByte_t, //指定地址讀取一個(gè)字節(jié) .AT24CXX_WriteOneByte = AT24CXX_WriteOneByte_t,//指定地址寫入一個(gè)字節(jié) .AT24CXX_WriteLenByte = AT24CXX_WriteLenByte_t, //指定地址開始寫入指定長(zhǎng)度的數(shù)據(jù) .AT24CXX_ReadLenByte = AT24CXX_ReadLenByte_t, //指定地址開始讀取指定長(zhǎng)度數(shù)據(jù) .AT24CXX_Write = AT24CXX_Write_t, //指定地址開始寫入指定長(zhǎng)度的數(shù)據(jù) .AT24CXX_Read = AT24CXX_Read_t, //指定地址開始讀取指定長(zhǎng)度的數(shù)據(jù) .AT24CXX_Init = AT24CXX_Init_t, //初始化IIC .AT24CXX_Check = AT24CXX_Check_t //檢查器件 };
簡(jiǎn)單分析:可以看出AT24CXX類中包含了IIC類的成員對(duì)象,這是一種包含關(guān)系,因?yàn)闆]有屬性上的一致性因此談不上繼承。
之所以將IIC的類對(duì)象作為AT24CXX類的成員是因?yàn)锳T24CXX的實(shí)現(xiàn)需要調(diào)用IIC的成員方法,IIC相當(dāng)于AT24CXX更下層的驅(qū)動(dòng),因此采用包含關(guān)系更合適。
因此我們?cè)谑褂肁T24CXX的時(shí)候只需要實(shí)例化AT24CXX類對(duì)象就行了,因?yàn)镮IC包含在AT24CXX類中間,因此不需要實(shí)例化IIC類對(duì)象,對(duì)外提供了較好的封裝接口。下面我們看具體的調(diào)用方法。
四.主函數(shù)main調(diào)用測(cè)試
在main函數(shù)中直接使用AT24C_64來完成所有操作,下面結(jié)合代碼來看:
#include "at24cxx.h" //為了確定AT24C_64的成員方法和引用操作對(duì)象AT24C_64 int main(void) { /************省略其他初始化工作****************/ //第一步:調(diào)用對(duì)象初始化方法來初始化AT24C64 AT24C_64.AT24CXX_Init(&AT24C_64); //第二步:調(diào)用對(duì)象檢測(cè)方法來檢測(cè)AT24C64 if(AT24C_64.AT24CXX_Check(&AT24C_64) == 0)
{ printf("AT24C64檢測(cè)成功\r\n");
} else{ printf("AT24C64檢測(cè)失敗\r\n");
} return 0;
}
可以看出所有的操作都是通過AT24C_64對(duì)象調(diào)用完成的,在我們初始化好AT24C_64對(duì)象之后就可以放心大膽的調(diào)用其成員方法,這樣封裝的好處就是一個(gè)設(shè)備對(duì)外只提供一個(gè)對(duì)象接口,簡(jiǎn)潔明了。
五.總結(jié)
本文詳細(xì)介紹了面向?qū)ο蠓椒▽?shí)現(xiàn)IIC驅(qū)動(dòng)封裝以及AT24CXX存儲(chǔ)器的封裝,最終對(duì)外僅提供一個(gè)操作對(duì)象接口,大大提高了代碼的復(fù)用性以及封裝性。
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