LL库-I2C

LL库-I2C

• Fang XS.
• 1452512966@qq.com
• 如果有错误，希望被指出

前言

• I2C通信介绍
• 使用STM32CubeMX生成的代码，通常不能直接使用。
• LL库的使用-USART
• 下文代码经以下平台验证可用:
• STM32L431RCT6 STM32F030C8T6

I2C

• 以I2C1 polling模式为例：
• 在I2C初始化最后添加：

  /* USER CODE BEGIN I2C1_Init 2 */
	LL_I2C_Enable(I2C1);
  /* USER CODE END I2C1_Init 2 */

• I2C读8位数据：

uint8_t I2C_read_reg_8bit(I2C_TypeDef *I2Cx , uint8_t SlaveAddr_IC, uint8_t addr_reg){

    uint8_t read_data;

    SlaveAddr_IC = SlaveAddr_IC<<1;

    uint32_t counter = 0;
    while(LL_I2C_IsActiveFlag_BUSY(I2Cx)==SET){
        counter++;
        if( counter == 25000){//~ 150ms
            Error_Handler();
            return 0xFF;
        }
    }
    LL_I2C_HandleTransfer(I2Cx, SlaveAddr_IC,LL_I2C_ADDRSLAVE_7BIT, 1,LL_I2C_MODE_SOFTEND,LL_I2C_GENERATE_START_WRITE ); //LL_I2C_GENERATE_START_READ
    while(LL_I2C_IsActiveFlag_TXE(I2Cx)==RESET);

    LL_I2C_TransmitData8(I2Cx, addr_reg);

    counter=0;
    while(LL_I2C_IsActiveFlag_TXE(I2Cx)==RESET){
        counter++;
        if( counter == 25000){//aproximate 150ms
            LL_I2C_ClearFlag_TXE(I2Cx);
            Error_Handler();
            return 0xFF;
        }
    }
    while(LL_I2C_IsActiveFlag_TC(I2Cx)==RESET);
    LL_I2C_HandleTransfer(I2Cx, SlaveAddr_IC, LL_I2C_ADDRSLAVE_7BIT, 1, LL_I2C_MODE_AUTOEND, LL_I2C_GENERATE_START_READ); //LL_I2C_MODE_SOFTEND
    while(LL_I2C_IsActiveFlag_RXNE(I2Cx)==RESET);
    read_data = LL_I2C_ReceiveData8(I2Cx);
    while(LL_I2C_IsActiveFlag_STOP(I2Cx)==RESET);
    LL_I2C_ClearFlag_STOP(I2Cx);
    return read_data;
}

• I2C读16位数据：

uint16_t I2C_read_reg_16bit(I2C_TypeDef *I2Cx , uint8_t SlaveAddr_IC, uint8_t addr_reg){
    uint8_t read_data[2], i=0;
    SlaveAddr_IC = SlaveAddr_IC<<1;
    uint32_t counter = 0;
    while(LL_I2C_IsActiveFlag_BUSY(I2Cx)==SET){
        counter++;
        if( counter == 25000 ){//aproximate 150ms
            Error_Handler();
            return 0xFF;
        }
    }
    LL_I2C_HandleTransfer(I2Cx, SlaveAddr_IC,LL_I2C_ADDRSLAVE_7BIT, 1,LL_I2C_MODE_SOFTEND,LL_I2C_GENERATE_START_WRITE ); //LL_I2C_GENERATE_START_READ
    while(LL_I2C_IsActiveFlag_TXE(I2Cx)==RESET);
    LL_I2C_TransmitData8(I2Cx, addr_reg);
    counter=0;
    while(LL_I2C_IsActiveFlag_TXE(I2Cx)==RESET){
        counter++;
        if( counter == 25000 ){//aproximate 150ms
            LL_I2C_ClearFlag_TXE(I2Cx);
            Error_Handler();
            return 0xFF;
        }
    }
    while(LL_I2C_IsActiveFlag_TC(I2Cx)==RESET);
    LL_I2C_HandleTransfer(I2Cx, SlaveAddr_IC, LL_I2C_ADDRSLAVE_7BIT, 2, LL_I2C_MODE_AUTOEND, LL_I2C_GENERATE_START_READ); //LL_I2C_MODE_SOFTEND
    while(!LL_I2C_IsActiveFlag_STOP(I2Cx)){
        if(LL_I2C_IsActiveFlag_RXNE(I2Cx)){
            read_data[i] = LL_I2C_ReceiveData8(I2Cx);
            i++;
        }
    }
    LL_I2C_ClearFlag_STOP(I2Cx);
    return (read_data[0]<<8) | read_data[1];
}

• I2C写8位数据：

ErrorStatus I2C_write_reg_8bit(I2C_TypeDef *I2Cx , uint8_t SlaveAddr_IC, uint8_t addr_reg, uint8_t value){
    SlaveAddr_IC = SlaveAddr_IC<<1;
    uint32_t counter = 0;
    while(LL_I2C_IsActiveFlag_BUSY(I2Cx) == SET){
        counter++;
        if( counter == 25000 ) {
            Error_Handler();
            return ERROR;
        }
    }
    LL_I2C_HandleTransfer(I2Cx, SlaveAddr_IC,LL_I2C_ADDRSLAVE_7BIT, 2,LL_I2C_MODE_AUTOEND,LL_I2C_GENERATE_START_WRITE ); //LL_I2C_GENERATE_START_READ
    while(LL_I2C_IsActiveFlag_TXE(I2Cx)==RESET);
    LL_I2C_TransmitData8(I2Cx, addr_reg);
    counter=0;
    while(LL_I2C_IsActiveFlag_TXE(I2Cx)==RESET){
        counter++;
        if( counter == 25000 ){//~ 150ms
            LL_I2C_ClearFlag_TXE(I2Cx);
            Error_Handler();
            return ERROR;
        }
    }
    LL_I2C_TransmitData8(I2Cx, value);
    while(LL_I2C_IsActiveFlag_TXE(I2Cx)==RESET);
    while(LL_I2C_IsActiveFlag_STOP(I2Cx)==RESET);
    LL_I2C_ClearFlag_STOP(I2Cx);
    return SUCCESS;
}

• I2C写16位数据：

ErrorStatus I2C_write_reg_16bit(I2C_TypeDef *I2Cx , uint8_t SlaveAddr_IC, uint8_t addr_reg, uint16_t value){
    SlaveAddr_IC = SlaveAddr_IC<<1;
    uint32_t counter = 0;
    while(LL_I2C_IsActiveFlag_BUSY(I2Cx)==SET){
        counter++;
        if( counter == 25000 ){//aproximate 150ms
            Error_Handler();
            return ERROR;
        }
    }
    LL_I2C_HandleTransfer(I2Cx, SlaveAddr_IC,LL_I2C_ADDRSLAVE_7BIT, 3,LL_I2C_MODE_AUTOEND,LL_I2C_GENERATE_START_WRITE ); //LL_I2C_GENERATE_START_READ
    while(LL_I2C_IsActiveFlag_TXE(I2Cx)==RESET);
    LL_I2C_TransmitData8(I2Cx, addr_reg);
    counter=0;
    while(LL_I2C_IsActiveFlag_TXE(I2Cx)==RESET){
        counter++;
        if( counter == 25000){//aproximate 150ms
            LL_I2C_ClearFlag_TXE(I2Cx);
            Error_Handler();
            return ERROR;
        }
    }
    LL_I2C_TransmitData8(I2Cx, (uint8_t)(value>>8)); //byte1
    while(LL_I2C_IsActiveFlag_TXE(I2Cx)==RESET);
    LL_I2C_TransmitData8(I2Cx, (uint8_t) value ); //byte2
    while(LL_I2C_IsActiveFlag_TXE(I2Cx)==RESET);
    while(LL_I2C_IsActiveFlag_STOP(I2Cx)==RESET);
    LL_I2C_ClearFlag_STOP(I2Cx);
    return SUCCESS;
}