i2c interrupt handler stm32

Question

I have some problems with I2C2 interrupts, I have enabled the interrupt but the handler interrupt never executes.

Here is the i2c2 initialization:

void i2c2InitSlave(void)
{
    I2C_DeInit(I2C2);
    GPIO_InitTypeDef GPIO_InitStructure;
    I2C_InitTypeDef I2C_InitStructure;

    /*I2C2 Peripheral clock enable */
    RCC_APB1PeriphClockCmd(RCC_APB1Periph_I2C2, ENABLE);

    /* Enable GPIO clock */
    RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOH, ENABLE);

    // I2C2 SCL and SDA Pin configuration
    GPIO_InitStructure.GPIO_OType = GPIO_OType_OD;
    GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;
    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_4 | GPIO_Pin_5;
    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
    GPIO_Init(GPIOH, &GPIO_InitStructure);

    GPIO_PinAFConfig(GPIOH, GPIO_PinSource4, GPIO_AF_I2C2);
        GPIO_PinAFConfig(GPIOH, GPIO_PinSource5, GPIO_AF_I2C2);

    /* Initialize I2C peripheral */
    /* I2C Init */
    I2C_InitStructure.I2C_Mode = I2C_Mode_I2C;
    I2C_InitStructure.I2C_DutyCycle = I2C_DutyCycle_2;
    I2C_InitStructure.I2C_OwnAddress1 = SLAVE_ADDRESS;
    I2C_InitStructure.I2C_Ack = I2C_Ack_Enable;
    I2C_InitStructure.I2C_ClockSpeed = 100000;
    I2C_InitStructure.I2C_AcknowledgedAddress = I2C_AcknowledgedAddress_7bit;

    /* Enable I2C2 */
    I2C_Cmd(I2C2, ENABLE);
    I2C_Init(I2C2, &I2C_InitStructure);

    Tx_Index = 0;
    Rx_Index = 0;
}

Here is the interrupt configuration:

NVIC_InitTypeDef NVIC_InitStructure;

/* Configure the I2C event priority */
NVIC_InitStructure.NVIC_IRQChannel                   = I2C2_EV_IRQn;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 1;
NVIC_InitStructure.NVIC_IRQChannelSubPriority        = 0;
NVIC_InitStructure.NVIC_IRQChannelCmd                = ENABLE;
NVIC_Init(&NVIC_InitStructure);

And here is the interrupt handler:

/**
* @brief  Interrupt handler for i2c interface.
* @param  None
* @retval None
*/

void I2C2_EV_IRQHandler(void)
{
    switch(I2C_GetLastEvent(I2C2))
    {
    case I2C_EVENT_SLAVE_RECEIVER_ADDRESS_MATCHED :
        break;
    case I2C_EVENT_SLAVE_BYTE_RECEIVED:
        i2c_read_packet[Rx_Index] = I2C_ReceiveData(I2C2); // Store the packet in i2c_read_packet.
        Rx_Index++;
        break;
    case I2C_EVENT_SLAVE_STOP_DETECTED :
        Rx_Index = 0;
        packets_recv_i2c++;
        i2cProcessPacket();
        break;
    case I2C_EVENT_SLAVE_TRANSMITTER_ADDRESS_MATCHED:
        I2C_SendData(I2C2, i2c_packet_to_send[0]);
        Tx_Index++;
        break;
    case I2C_EVENT_SLAVE_BYTE_TRANSMITTED:
        I2C_SendData(I2C2, i2c_packet_to_send[Tx_Index]);
        Tx_Index++;
        break;
    case I2C_EVENT_SLAVE_ACK_FAILURE:
        Tx_Index = 0;
        packets_sent_i2c++;
        break;
    default:
        break;
    }
}

Any idea? BR, Edgar.

Answer 1

Okay, so you've listed your interrupt config and handler, but what about your I2C initialization in-general?

You won't be generating any interrupts if the I2C isn't initialized.

You should recognize this block (or some analog of it):

I2C_InitTypeDef  I2C_InitStructure;

/* I2C Struct Initialize */  
I2C_InitStructure.I2C_Mode = I2C_Mode_I2C;
I2C_InitStructure.I2C_DutyCycle = I2C_DUTYCYCLE;
I2C_InitStructure.I2C_OwnAddress1 = 0xA0;
I2C_InitStructure.I2C_Ack = I2C_Ack_Enable;
I2C_InitStructure.I2C_ClockSpeed = I2C_SPEED;
I2C_InitStructure.I2C_AcknowledgedAddress = I2C_AcknowledgedAddress_7bit;

/* I2C Enable and Init */
I2C_Cmd(I2C2, ENABLE);
I2C_Init(I2Cx, &I2C_InitStructure);  

I2C_Config(); //See implementation below

I2C_ITConfig(I2Cx, ENABLE); //Part of the STM32 I2C driver    

Where I2C_Config could be defined as follows:

void I2C_Config(void){
  GPIO_InitTypeDef  GPIO_InitStructure;

  /* RCC Configuration */
  /*I2C Peripheral clock enable */
  RCC_APB1PeriphClockCmd(I2Cx_CLK, ENABLE);

  /*SDA GPIO clock enable */
  RCC_AHB1PeriphClockCmd(I2Cx_SDA_GPIO_CLK, ENABLE);

  /*SCL GPIO clock enable */
  RCC_AHB1PeriphClockCmd(I2Cx_SCL_GPIO_CLK, ENABLE);

  /* Reset I2Cx IP */
  RCC_APB1PeriphResetCmd(I2Cx_CLK, ENABLE);

  /* Release reset signal of I2Cx IP */
  RCC_APB1PeriphResetCmd(I2Cx_CLK, DISABLE);

  /* GPIO Configuration */
  /*Configure I2C SCL pin */
  GPIO_InitStructure.GPIO_Pin = I2Cx_SCL_PIN;
  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;
  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
  GPIO_InitStructure.GPIO_OType = GPIO_OType_OD;
  GPIO_InitStructure.GPIO_PuPd  = GPIO_PuPd_NOPULL;
  GPIO_Init(I2Cx_SCL_GPIO_PORT, &GPIO_InitStructure);

  /*Configure I2C SDA pin */
  GPIO_InitStructure.GPIO_Pin = I2Cx_SDA_PIN;
  GPIO_Init(I2Cx_SDA_GPIO_PORT, &GPIO_InitStructure);

  /* Connect PXx to I2C_SCL */
  GPIO_PinAFConfig(I2Cx_SCL_GPIO_PORT, I2Cx_SCL_SOURCE, I2Cx_SCL_AF);

  /* Connect PXx to I2C_SDA */
  GPIO_PinAFConfig(I2Cx_SDA_GPIO_PORT, I2Cx_SDA_SOURCE, I2Cx_SDA_AF);

}

And the I2C_InitTypeDef is defined as follows:

typedef struct  
{
  uint32_t I2C_ClockSpeed;      //Specifies the clock frequency.
                                //This parameter must be set to a value lower than 400kHz

  uint16_t I2C_Mode;            //Specifies the I2C mode.
                                //This parameter can be a value of @ref I2C_mode 

  uint16_t I2C_DutyCycle;       //Specifies the I2C fast mode duty cycle.
                                //This parameter can be a value of @ref I2C_duty_cycle_in_fast_mode 

  uint16_t I2C_OwnAddress1;     //Specifies the first device own address.
                                //This parameter can be a 7-bit or 10-bit address.

  uint16_t I2C_Ack;             //Enables or disables the acknowledgement.
                                //This parameter can be a value of @ref I2C_acknowledgement

  uint16_t I2C_AcknowledgedAddress; 
                                //Specifies if 7-bit or 10-bit address is acknowledged.
                                //This parameter can be a value of @ref I2C_acknowledged_address
}I2C_InitTypeDef;

Note: Using a set of #define's (perhaps in a header) during configuration makes life easier. For example:

#define I2Cx                          I2C1
#define I2Cx_CLK                      RCC_APB1Periph_I2C1
#define I2Cx_SDA_GPIO_CLK             RCC_AHB1Periph_GPIOB
#define I2Cx_SDA_PIN                  GPIO_Pin_9                
#define I2Cx_SDA_GPIO_PORT            GPIOB                       
#define I2Cx_SDA_SOURCE               GPIO_PinSource9
#define I2Cx_SDA_AF                   GPIO_AF_I2C1

#define I2Cx_SCL_GPIO_CLK             RCC_AHB1Periph_GPIOB
#define I2Cx_SCL_PIN                  GPIO_Pin_6                
#define I2Cx_SCL_GPIO_PORT            GPIOB                    
#define I2Cx_SCL_SOURCE               GPIO_PinSource6
#define I2Cx_SCL_AF                   GPIO_AF_I2C1

...And MOST importantly, take a look at "stm32f4xx_i2c.c" available here. Read through the "How to Use This Driver" comment at the top.