I2C主接收器不起作用，仅在调试器中有效

Question

我正在使用基于STM32F10x的微控制器，并且正在与从设备通信。直到我向从属设备发送读取数据的命令为止，一切似乎都在进行，但是在while循环中它会卡住，因为我的BTF标志永远不会变高。如果我一起删除while循环，我将得到0x81而没有任何实际数据。

        I2C1->CR1 |= I2C_CR1_START; // send start bit   
        delay(30000);
        //while((I2C1->SR1 & I2C_SR1_TXE)); //read SR1
        (void)I2C1->SR1;
        I2C1->DR = 0x80; // slave address writing to DR 1000 0000   0x40 with R/W bit as 
        delay(30000);
        while(!(I2C1->SR1 & I2C_SR1_TXE))// make sure transmit is empty.
        {
        }
        (void)I2C1->SR1;
        (void)I2C1->SR2;
        I2C1->DR = 0xE3; // command for slave to send data, hold master mode on, clock stretching enabled
        delay(30000);
        while(!(I2C1->SR1 & I2C_SR1_TXE))
        {
        }
        delay(80000);
        I2C1->CR1 |= I2C_CR1_START; // send start bit   
        (void)I2C1->SR1;

        I2C1->DR = 0x81;
        delay(1000);
        while(!(I2C1->SR1 & I2C_SR1_BTF)) // waiting for byte to finish transfer
        {
        }
        dataaa[0] = I2C1->DR;
        I2C1->CR1 &= ~I2C_CR1_ACK;// acknowledgement disabled
        dataaa[1] = I2C1->DR;
        I2C1->CR1 |= I2C_CR1_STOP;// acknowledgement disabled
        temperature = temperature + dataaa[0];
        temperature = temperature << 8;
        temperature = temperature + dataaa[1];