stm32 硬件iic

ninghaojie

问一下大家，我用stm32f103的硬件iic，示波器看不到起始信号，是什么原因？
代码如下：

void GPIO_Configuration()

{

GPIO_InitTypeDef GPIO_InitStructure;

  RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOB, ENABLE);

    

  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_6 | GPIO_Pin_7;

  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_OD;       

  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;

  GPIO_Init(GPIOB, &GPIO_InitStructure);

}

void IIC_Configuration()

{

I2C_InitTypeDef    I2C_InitStructure;

RCC_APB1PeriphClockCmd(RCC_APB1Periph_I2C1, ENABLE);

I2C_InitStructure.I2C_Mode  = I2C_Mode_I2C; //IIC模式

I2C_InitStructure.I2C_DutyCycle   = I2C_DutyCycle_2;

I2C_InitStructure.I2C_OwnAddress1 = 0x30; //器件地址

I2C_InitStructure.I2C_Ack  = I2C_Ack_Enable; //IIC应答使能

I2C_InitStructure.I2C_AcknowledgedAddress =  I2C_AcknowledgedAddress_7bit; //应答7位地址

I2C_InitStructure.I2C_ClockSpeed  = 200000;    //100KHZ

I2C_Init(I2C1, &I2C_InitStructure);

I2C_Cmd(I2C1, ENABLE);

I2C_AcknowledgeConfig(I2C1, ENABLE);      //允许应答模式

}

int main(void)

{

   

    SystemInit();

delay_init(72); //延时初始化

GPIO_Configuration();

IIC_Configuration();

while(1)

{

        I2C_GenerateSTART(I2C1, ENABLE);

delay_ms(100);

}

}