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I2C slave not ACK

Question asked by eaglewatch Employee on Jan 14, 2014
Latest reply on Jan 17, 2014 by eaglewatch

                                   
           
           
           
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I have an issue with STM32F0 Discovery. I am using I2C1 (like master) to send start condition and address to I2C2 (slave) on the same board. I am able to generate propertly the signal but the IC2 (slave) is not able to generate an ACK on 9th clk

What's wrong? Here my code about the setup:

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void set_I2C(void){
  GPIO_InitTypeDef GPIO_InitStructure;
  I2C_InitTypeDef I2C_InitStructure;

  RCC_AHBPeriphClockCmd(RCC_AHBPeriph_GPIOB, ENABLE);
     RCC_APB1PeriphClockCmd(RCC_APB1Periph_I2C1, ENABLE);
     /* Configure the I2C clock source. The clock is derived from the HSI */
     RCC_I2CCLKConfig(RCC_I2C1CLK_SYSCLK);

     GPIO_PinAFConfig(GPIOB, GPIO_PinSource6, GPIO_AF_1);
     GPIO_PinAFConfig(GPIOB, GPIO_PinSource7, GPIO_AF_1);

     //Configure pins: SCL and SDA ------------------
     GPIO_InitStructure.GPIO_Pin = GPIO_Pin_6 | GPIO_Pin_7;
     GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
     GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;
     GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL;
     GPIO_InitStructure.GPIO_OType = GPIO_OType_OD;
     GPIO_Init(GPIOB, &GPIO_InitStructure);

 

     I2C_DeInit(I2C1);
     I2C_Cmd(I2C1, DISABLE);
     I2C_InitStructure.I2C_AnalogFilter = I2C_AnalogFilter_Enable;
     I2C_InitStructure.I2C_DigitalFilter = 0x00;
     I2C_InitStructure.I2C_OwnAddress1 = 0x40;
     I2C_InitStructure.I2C_Mode = I2C_Mode_I2C;
     I2C_InitStructure.I2C_Ack = I2C_Ack_Enable;
     //I2C_InitStructure.I2C_Timing = 0xA0120227;
     //I2C_InitStructure.I2C_Timing = 0x20310A0D;
     I2C_InitStructure.I2C_Timing =0xB0420F13; //100KHz (see page 529 - table 73 in the manual reference)
     I2C_InitStructure.I2C_AcknowledgedAddress = I2C_AcknowledgedAddress_7bit;

     I2C_Init(I2C1, &I2C_InitStructure);
     //I2C_NumberOfBytesConfig(I2C1, 8);
     //I2C_AutoEndCmd(I2C1, ENABLE);

     I2C_Cmd(I2C1, ENABLE);

     //I2C_ITConfig(I2C1, I2C_FLAG_TXE, ENABLE);

 

     //Set up of I2C2
  RCC_APB1PeriphClockCmd(RCC_APB1Periph_I2C2, ENABLE);
     RCC_AHBPeriphClockCmd(RCC_AHBPeriph_GPIOB, ENABLE);

        // Configure the I2C clock source. The clock is derived from the HSI
        //RCC_I2CCLKConfig(RCC_PCLKConfig());

        GPIO_PinAFConfig(GPIOB, GPIO_PinSource11, GPIO_AF_1);
        GPIO_PinAFConfig(GPIOB, GPIO_PinSource10, GPIO_AF_1);

        //Configure pins: SCL and SDA ------------------
        GPIO_InitStructure.GPIO_Pin = GPIO_Pin_11 | GPIO_Pin_10;
        GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
        GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;
        GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL;
        GPIO_InitStructure.GPIO_OType = GPIO_OType_OD;
        GPIO_Init(GPIOB, &GPIO_InitStructure);

        I2C_DeInit(I2C2);
        I2C_Cmd(I2C2, DISABLE);
        I2C_InitStructure.I2C_AnalogFilter = I2C_AnalogFilter_Disable;
        I2C_InitStructure.I2C_DigitalFilter = 0x00;
        I2C_InitStructure.I2C_OwnAddress1 = 0x30; // MPU6050 7-bit adress = 0x68, 8-bit adress = 0xD0;
     I2C_InitStructure.I2C_Mode = I2C_Mode_I2C;
     I2C_InitStructure.I2C_Ack = I2C_Ack_Enable;

     I2C_InitStructure.I2C_Timing =0xB0420F13;
     I2C_InitStructure.I2C_AcknowledgedAddress = I2C_AcknowledgedAddress_7bit;

        I2C_Init(I2C2, &I2C_InitStructure);
        //I2C_NumberOfBytesConfig(I2C1, 8);
        //I2C_AutoEndCmd(I2C1, ENABLE);

     I2C_Cmd(I2C2, ENABLE);

     /*I2C2->CR1&=~I2C_OAR1_OA1EN;
    I2C2->CR1&=~I2C_OAR2_OA2EN;
    I2C2->CR1|=I2C_CR1_SBC; //Slave Byte Control
    I2C_GeneralCallCmd(I2C2, ENABLE);
    I2C2->CR1|=I2C_CR1_ADDRIE;
    I2C2->CR2&=~I2C_CR2_NACK;
    I2C2->OAR1|=I2C_OAR1_OA1EN;*/

 

         /*I2C_Cmd(I2C2, DISABLE);
          I2C2->CR1|=I2C_CR1_SBC; //Slave Byte Control
          I2C_Cmd(I2C2, ENABLE);
          I2C_StretchClockCmd(I2C1, DISABLE);*/

    I2C_ITConfig(I2C2, I2C_AcknowledgedAddress_7bit, ENABLE);
    /*I2C_ITConfig(I2C2, I2C_ISR_ADDR, ENABLE);
    I2C_ITConfig(I2C2, IS_I2C_ACKNOWLEDGE_ADDRESS(0x30), ENABLE);
    I2C_AcknowledgeConfig(I2C2, ENABLE);
*/

      NVIC_InitTypeDef NVIC_InitStructure;
     /* Configure the I2C2 interrupt priority */
     NVIC_InitStructure.NVIC_IRQChannel = I2C2_IRQn;
     NVIC_InitStructure.NVIC_IRQChannelPriority=1;
     NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
     NVIC_Init(&NVIC_InitStructure);
}

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