【求助】GD32模拟I2C问题

Jamiexus19

• 时序及其示波器显示波形如下所示，黄色为SDA。前面发送的数据没有任何问题，但是当接收数据的时候出现了如下所示问题。试过很多方法无果前来请教各位大佬！

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• GPIO设置如图所示，SCK和SDA均为推挽输出。

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• 代码如下

• 
  void i2c_start(void)
  {
      BK1080_SDA_DIR_OUT;
      BK1080_SDA_HIGH;
      bk1080_delay(1);
      BK1080_SCK_HIGH;
      bk1080_delay(1);
      BK1080_SDA_LOW;
      bk1080_delay(1);
      BK1080_SCK_LOW;
      bk1080_delay(1);
  }
  
  static void i2c_stop(void)
  {
      BK1080_SDA_DIR_OUT;
      BK1080_SDA_LOW;
      bk1080_delay(1);
      BK1080_SCK_LOW;
      bk1080_delay(1);
      BK1080_SCK_HIGH;
      bk1080_delay(1);
      BK1080_SDA_HIGH;
      bk1080_delay(1);
  }
  
  static void i2c_send(uint8_t data)
  {
      BK1080_SDA_DIR_OUT;
      BK1080_SCK_LOW;
      bk1080_delay(2);
      for (uint8_t i = 0; i < 8; i++)
      {
          if (data & 0x80)
              BK1080_SDA_HIGH;
          else
              BK1080_SDA_LOW;
          bk1080_delay(1);
          BK1080_SCK_HIGH;
          bk1080_delay(1);
          BK1080_SCK_LOW;
          bk1080_delay(2);
          data <<= 1;
      }
  }
  
  static uint8_t i2c_read(void)
  {
      uint8_t data = 0;
      BK1080_SDA_DIR_IN;
      BK1080_SCK_LOW;
      bk1080_delay(2);
      for (uint8_t i = 0; i < 8; i++)
      {
          data <<= 1;
          BK1080_SCK_HIGH;
          bk1080_delay(1);
          data |= BK1080_SDA_READ;
          bk1080_delay(1);
          BK1080_SCK_LOW;
          bk1080_delay(2);
      }
      return data;
  }
  
  static void i2c_send_ack(iic_ack_t ack)
  {
      BK1080_SDA_DIR_OUT;
      BK1080_SCK_LOW;
      bk1080_delay(1);
      if (ack)
          BK1080_SDA_HIGH;
      else
          BK1080_SDA_LOW;
      bk1080_delay(1);
      BK1080_SCK_HIGH;
      bk1080_delay(1);
      BK1080_SCK_LOW;
      bk1080_delay(2);
  }
  
  static uint8_t i2c_get_ack(void)
  {
      uint8_t ack;
      BK1080_SDA_DIR_IN;  
      BK1080_SCK_LOW;
      bk1080_delay(5);
      BK1080_SCK_HIGH;
      bk1080_delay(1);
      ack = BK1080_SDA_READ;
      bk1080_delay(1);
      BK1080_SCK_LOW;
      bk1080_delay(2);
      return ack;
  }
  

Jamiexus19

MCU为GD32F330CBT6
Device ID 为0x80

Nalimca

因为主机是IO口模拟IIC,所以发送没问题.但是可能从机不是IO模拟的IIC,从机发送IIC时因为没有上拉电阻所以驱动能力不够?

Nalimca

另外看起来你这个波形很奇怪请检查1.主从机是否共地2.主从机电压是否一直.可以考虑SCL与SDA线上分别串联一个10-100欧姆电阻来增加通讯稳定性.