I2C on STM32F4 [SOLVED]

[DELTA67]

Ok, I'll retry again.

[DELTA67]

I simulated that example with a 24c02 (Addr = 0xA0) and it partially worked.

How did you built it? It seems that it's based on the standard peripheral driver. The keil uvision 5 uses the CUBEMX HAL.
can you attach your project and all the files used in simulation please?

[DavidAlfa]

The link I posted earlier only uses CMSIS headers, no peripheral library of any kind, should work just fine.
Have you tried?
I'm using CubeIDE.

[DELTA67]

I've found a working example for STM32F4 here:
https://blog.embeddedexpert.io/?p=613
I've made some modifications in order to get it working for the BLack PILL (F411):

* In main.c:
- I commented the clock config in order to use default 16MHz HSI clock

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//SysClockConfig();
* In i2c.c:
- I enabled the pull-ups for PB8 and PB9

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GPIOB->PUPDR|= 1<<16 | 1<<18;
- I modified the values of CR2, CCR and TRISE registers:

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I2C1->CR2|= 16; // APB1 = 16MHz
I2C1->CCR|= 80;
I2C1->TRISE= 11;
Et voilà !!

But when testing in PROTEUS it does not work as before. No start condition and no address transmission.
Later, I'll try with a lower frequency for APB1 (8MHz) and lower freq for SCL (50kHz) and see.
Thanks for ALL for your help

[DavidAlfa]

The model is definitely bugged.
As in the datasheet, I2C SR2 MSL bit goes to 0 (Slave mode) when a stop is detected.
I have some code using that flag, it worked perfectly in real hardware.
MSL never goes back to 0 in Proteus.

Just use LL. Does exactly what you would do by hand. No overhead, no bloat. Just skip rewriting the wheel.
This is my function:

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ErrorStatus I2C1_MasterTransmit(uint8_t DevAddress, uint8_t *pData, uint16_t Size)
{
  ErrorStatus status = SUCCESS;
  LL_I2C_GenerateStartCondition(I2C1);
  while(LL_I2C_IsActiveFlag_SB(I2C1) != 1);

  LL_I2C_TransmitData8(I2C1, DevAddress);
  while(!LL_I2C_IsActiveFlag_ADDR(I2C1) || !LL_I2C_IsActiveFlag_TXE(I2C1)){
    if(LL_I2C_IsActiveFlag_AF(I2C1))
      break;
  }
  LL_I2C_ClearFlag_ADDR(I2C1);
  if(LL_I2C_IsActiveFlag_AF(I2C1)){
    status = ERROR;
    LL_I2C_ClearFlag_AF(I2C1);
  }
  else{
    while(Size--)
    {
      LL_I2C_TransmitData8(I2C1, *pData++);
      while(!LL_I2C_IsActiveFlag_TXE(I2C1));
      if(LL_I2C_IsActiveFlag_AF(I2C1)){
        status = ERROR;
        break;
      }
    }
  }
  while(!LL_I2C_IsActiveFlag_BTF(I2C1));
  LL_I2C_GenerateStopCondition(I2C1);
  while(LL_I2C_IsActiveFlag_MSL(I2C1));
  return status;
}


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__STATIC_INLINE void LL_I2C_GenerateStartCondition(I2C_TypeDef *I2Cx)
{
  SET_BIT(I2Cx->CR1, I2C_CR1_START);
}


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__STATIC_INLINE void LL_I2C_GenerateStopCondition(I2C_TypeDef *I2Cx)
{
  SET_BIT(I2Cx->CR1, I2C_CR1_STOP);
}


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__STATIC_INLINE void LL_I2C_TransmitData8(I2C_TypeDef *I2Cx, uint8_t Data)
{
  MODIFY_REG(I2Cx->DR, I2C_DR_DR, Data);
}


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__STATIC_INLINE uint32_t LL_I2C_IsActiveFlag_ADDR(I2C_TypeDef *I2Cx)
{
  return (READ_BIT(I2Cx->SR1, I2C_SR1_ADDR) == (I2C_SR1_ADDR));
}

And so on. That's LL. Inlining avoids any slow calls. Simple functions and calls, nothing convoluted.

[DELTA67]

The model is definitely bugged.

I confirm that.
I've tested with different APB1 frequencies (16, 8 and 4MHz) and SCL frequencies 100 and 50kHz.

Thanks David alpha, wek and Others.
How to tag this thread [SOLVED] ?

[DavidAlfa]

Edit the title in the first message?

[DELTA67]

Ok, thanks.