I2C?的配置

static void InitI2C()

{

I2C_InitTypeDef I2C_InitStructure;

GPIO_InitTypeDef GPIO_InitA;

RCC_APB1PeriphClockCmd(RCC_APB1Periph_I2C1,ENABLE);//使能I2C1,I2C2的時鐘

RCC_I2CCLKConfig(RCC_I2C1CLK_SYSCLK);//時鐘源設定

GPIO_PinAFConfig(GPIOB, GPIO_PinSource8, GPIO_AF_1); ?//配置PB8 成第二功能引腳 I2C1_SCL

GPIO_PinAFConfig(GPIOB, GPIO_PinSource9, GPIO_AF_1); ?//配置PB9 成第二功能引腳 I2C1_SDA

GPIO_InitA.GPIO_Pin = GPIO_Pin_8 | GPIO_Pin_9;

GPIO_InitA.GPIO_Mode = GPIO_Mode_AF;

GPIO_InitA.GPIO_Speed = GPIO_Speed_50MHz;

GPIO_InitA.GPIO_OType = GPIO_OType_PP;

GPIO_InitA.GPIO_PuPd = GPIO_PuPd_UP;

GPIO_Init(GPIOB, &GPIO_InitA);

I2C_InitStructure.I2C_Mode = I2C_Mode_SMBusHost;

I2C_InitStructure.I2C_AcknowledgedAddress = I2C_AcknowledgedAddress_7bit;

I2C_InitStructure.I2C_AnalogFilter = I2C_AnalogFilter_Enable;

I2C_InitStructure.I2C_DigitalFilter = 0x01;

I2C_InitStructure.I2C_OwnAddress1 = 0x00;

I2C_InitStructure.I2C_Ack = I2C_Ack_Enable;

I2C_InitStructure.I2C_Timing = 0x0090174F;

I2C_Init(I2C1, &I2C_InitStructure);

I2C_Cmd(I2C1, ENABLE);

}

一樣的配置方案，I2C_Timing的意思請移步本博客GY30那篇文章。?

I2C引腳為PB8 與PB9（使用的C8T6，f4p6可以用PA的）

#define AT24C16_Base_Address 0xA0

void AT24C16_WriteByte(uint8_t Page,uint8_t WordAddress,uint8_t Data);

uint8_t AT24C16_ReadByte(uint8_t Page,uint8_t WordAddress);

void AT24C16_PageWrite(uint8_t Page,uint8_t WordAddress,uint8_t Length,uint8_t* Data);

void AT24C16_SequentialRead(uint8_t Page,uint8_t WordAddress, uint8_t length , uint8_t* p);

下面是相關函數：

void AT24C16_WriteByte(uint8_t Page,uint8_t WordAddress,uint8_t Data)

{

if(WordAddress > 0x10)

{

return;

}

WordAddress |= ( Page & 0x0F ) << 4;

while(I2C_GetFlagStatus(I2C1, I2C_FLAG_BUSY) != RESET);//IF BUSY

I2C_TransferHandling(I2C1,AT24C16_Base_Address | ( ( Page & 0xF0 ) >> 3 ),2,I2C_AutoEnd_Mode,I2C_Generate_Start_Write);

while(I2C_GetFlagStatus(I2C1, I2C_FLAG_TXIS) == RESET);//If Write OK

I2C_SendData(I2C1,WordAddress);

while(I2C_GetFlagStatus(I2C1, I2C_FLAG_TXIS) == RESET);//If Write OK

I2C_SendData(I2C1,Data);

while(I2C_GetFlagStatus(I2C1, I2C_FLAG_STOPF) == RESET);

}

uint8_t AT24C16_ReadByte(uint8_t Page,uint8_t WordAddress)

{

uint8_t Recev = 0x00;

if(WordAddress > 0x10)

{

return 0;

}

WordAddress |= ( Page & 0x0F ) << 4;

while(I2C_GetFlagStatus(I2C1, I2C_FLAG_BUSY) != RESET);//IF BUSY

I2C_TransferHandling(I2C1,AT24C16_Base_Address | ( ( Page & 0xF0 ) >> 3 ),1,I2C_SoftEnd_Mode,I2C_Generate_Start_Write);

while(I2C_GetFlagStatus(I2C1, I2C_FLAG_TXIS) == RESET);//If Write OK

I2C_SendData(I2C1,WordAddress);

while(I2C_GetFlagStatus(I2C1, I2C_FLAG_TC) == RESET);

I2C_TransferHandling(I2C1,AT24C16_Base_Address | ( ( Page & 0xF0 ) >> 3 ),1,I2C_AutoEnd_Mode,I2C_Generate_Start_Read);

while(I2C_GetFlagStatus(I2C1, I2C_FLAG_RXNE) == RESET);

Recev = I2C_ReceiveData(I2C1);

while(I2C_GetFlagStatus(I2C1, I2C_FLAG_STOPF) == RESET);

return Recev;

}

下面是頁讀取，頁寫入：

void AT24C16_PageWrite(uint8_t Page,uint8_t WordAddress,uint8_t Length,uint8_t* Data)

{

uint8_t i = 0;

if(WordAddress > 0x10)

{

return;

}

WordAddress |= ( Page & 0x0F ) << 4;

while(I2C_GetFlagStatus(I2C1, I2C_FLAG_BUSY) != RESET);//IF BUSY

I2C_TransferHandling(I2C1,AT24C16_Base_Address | ( ( Page & 0xF0 ) >> 3 ),Length + 1,I2C_AutoEnd_Mode,I2C_Generate_Start_Write);

while(I2C_GetFlagStatus(I2C1, I2C_FLAG_TXIS) == RESET);//If Write OK

I2C_SendData(I2C1,WordAddress);

for(i = 0;i < Length; i++)

{

while(I2C_GetFlagStatus(I2C1, I2C_FLAG_TXIS) == RESET);//If Write OK

I2C_SendData(I2C1,Data[i]);

}

while(I2C_GetFlagStatus(I2C1, I2C_FLAG_STOPF) == RESET);

}

void AT24C16_SequentialRead(uint8_t Page,uint8_t WordAddress, uint8_t length , uint8_t* p)

{

uint8_t i;

if(WordAddress > 0x10)

{

return;

}

WordAddress |= ( Page & 0x0F ) << 4;

while(I2C_GetFlagStatus(I2C1, I2C_FLAG_BUSY) != RESET);//IF BUSY

I2C_TransferHandling(I2C1,AT24C16_Base_Address | ( ( Page & 0xF0 ) >> 3 ),1,I2C_SoftEnd_Mode,I2C_Generate_Start_Write);

while(I2C_GetFlagStatus(I2C1, I2C_FLAG_TXIS) == RESET);//If Write OK

I2C_SendData(I2C1,WordAddress);

while(I2C_GetFlagStatus(I2C1, I2C_FLAG_TC) == RESET);

I2C_TransferHandling(I2C1,AT24C16_Base_Address | ( ( Page & 0xF0 ) >> 3 ),length,I2C_AutoEnd_Mode,I2C_Generate_Start_Read);

for(i = 0;i < length;i++)

{

while(I2C_GetFlagStatus(I2C1, I2C_FLAG_RXNE) == RESET);

p[i] = I2C_ReceiveData(I2C1);

}

while(I2C_GetFlagStatus(I2C1, I2C_FLAG_STOPF) == RESET);

}

感覺沒什么說的，GY30那篇文章基本都說完了，添點小知識點吧。

I2C_AutoEnd_Mode，顧名思義，操作length字節后自動添加STOP。?

I2C_SoftEnd_Mode ，同樣顧名思義，操作length字節后需要手動添加STOP。( I2C_GenerateSTOP() )?

這個模式比自動多了一步，需要 I2C_GetFlagStatus(I2C1, I2C_FLAG_TC) ，Translate Completed，是否傳輸完成，自動模式下訪問這個會得到Reset值，然而手動模式下需要訪問他，然后生成Stop。

然后……差不多了吧？舉個 上面網址的例子吧，我覺得很多人不會看……

所以在編寫程序對AT24C16第100頁的第3個字節進行寫數據的時候，步驟如下：?

1）發送起始信號；?

2）發送器件地址0XA6（1010 0110，1010是固定地址，011是頁地址的高三位，0表示寫操作）；?

3）發送操作地址0X43（0100 0011，0100是頁地址的低四位，0011是頁地址偏移量，即第100頁內的第三個字節，?

4）發送要寫的數據，?

5）發送終止信號。

我相信各位最起碼都看了AT24C16的地址了，0xA0。（再次引用暢學電子網的圖片）?

P0P1P2為頁地址高三位，發送的字地址（WordAddress）高四位為頁地址的第四位，低四位為字地址。?

AT24C16有128頁，每頁16bytes。所以正好匹配上。?

寫的間隔至少為5ms，否則用循環等待的話I2C會卡死。

以上。?