I2C1 stops working over 8MHz STM32F042F6P6

[Davaol19]

Hello all,

I'm having problems with I2C1, i have a code that works perfectly while i configure the HCLK to 8MHz but it stops working when i set any higher frequency. Has anybody faced similar problem?

I am using STM32CubeIDE for setting the project, this microcontroller has a separate clock from HCLK, and i can't understand why I'm having this problem.

 

Thanks in advance.

[Andrew Neil]

When you increase the HCLK, do you adjust the I2C to match?

And what, exactly, do you mean by "stops working"?

Have you viewed the I2C signals on a scope? How do they look?

[Davaol19]

Thank for your fast reply Andrew,

This is the way i configured the project trying to run the microcontroller at 16MHz (this node is working as slave), but with this configuration i can't receive anything on the master. But if i change de HCLK frequency to 8MHz, all works perfectly. 

With "it's not working" i mean that with 8MHz in HCLK the comunication works as i expect but if i put any higher frequency te comunication stops.

I'm not seen the signals on the oscilloscope yet, i'm waiting for a mate to let me use his.

[Andrew Neil]

Also show your configuration for 8MHz ...

[Davaol19]

I am using STM32F042F6P6

[Davaol19]

Here it is:

 

 

[TDK]

> it stops working

> te comunication stops

What exactly is happening that leads you to believe that communication stops? Does something in your code return an error message? Are the read values not as expected?

Are you debugging and stepping through the code or are you just running it and expecting an LED to blink or something, and inferring communcation stops from lack of the LED blinking?

[Davaol19]

Yes, i'm sorry but i'm a beginner and i don't have a lot of knowledge debugging, with " not working" i mean that i'm not receiving the data on the master. 

The code works in an specific frequency only, but in other projects i tried and no matters de frequency if the project is set with STM32CubeIDE or MX, the I2C still working.

[TDK]

Monitor return values from HAL_I2C functions.

Again, "not receiving data" is ambiguous. Be more specific. How are you expecting to receive the data? What should STM32 do with data in order for you to receive it? What makes you think it's not received?

[Tesla DeLorean]

So in this context the STM32F042F6P6 is the SLAVE device on the bus?

What device is the MASTER?

Show configuration of I2C at both ends of the transaction

And the ERROR status either end is reporting, ie the Master is not seeing a NACK from the Slave when it expects it.

[Davaol19]

Configuration in the Slave (STM32F042F6P6):

 

 

/**************************************************************************************/

static void MX_I2C1_Init(void)

{



/* USER CODE BEGIN I2C1_Init 0 */



/* USER CODE END I2C1_Init 0 */



/* USER CODE BEGIN I2C1_Init 1 */



/* USER CODE END I2C1_Init 1 */

hi2c1.Instance = I2C1;

hi2c1.Init.Timing = 0x00303D5B;

hi2c1.Init.OwnAddress1 = 194;

hi2c1.Init.AddressingMode = I2C_ADDRESSINGMODE_7BIT;

hi2c1.Init.DualAddressMode = I2C_DUALADDRESS_DISABLE;

hi2c1.Init.OwnAddress2 = 0;

hi2c1.Init.OwnAddress2Masks = I2C_OA2_NOMASK;

hi2c1.Init.GeneralCallMode = I2C_GENERALCALL_DISABLE;

hi2c1.Init.NoStretchMode = I2C_NOSTRETCH_DISABLE;

if (HAL_I2C_Init(&hi2c1) != HAL_OK)

{

Error_Handler();

}



/** Configure Analogue filter

*/

if (HAL_I2CEx_ConfigAnalogFilter(&hi2c1, I2C_ANALOGFILTER_ENABLE) != HAL_OK)

{

Error_Handler();

}



/** Configure Digital filter

*/

if (HAL_I2CEx_ConfigDigitalFilter(&hi2c1, 0) != HAL_OK)

{

Error_Handler();

}

/* USER CODE BEGIN I2C1_Init 2 */



/* USER CODE END I2C1_Init 2 */



}

/**************************************************************************************/



void HAL_I2C_MspInit(I2C_HandleTypeDef* hi2c)

{

GPIO_InitTypeDef GPIO_InitStruct = {0};

if(hi2c->Instance==I2C1)

{

/* USER CODE BEGIN I2C1_MspInit 0 */



/* USER CODE END I2C1_MspInit 0 */



__HAL_RCC_GPIOA_CLK_ENABLE();

/**I2C1 GPIO Configuration

PA9 ------> I2C1_SCL

PA10 ------> I2C1_SDA

*/

GPIO_InitStruct.Pin = GPIO_PIN_9|GPIO_PIN_10;

GPIO_InitStruct.Mode = GPIO_MODE_AF_OD;

GPIO_InitStruct.Pull = GPIO_NOPULL;

GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_HIGH;

GPIO_InitStruct.Alternate = GPIO_AF4_I2C1;

HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);



/* Peripheral clock enable */

__HAL_RCC_I2C1_CLK_ENABLE();

/* I2C1 interrupt Init */

HAL_NVIC_SetPriority(I2C1_IRQn, 0, 0);

HAL_NVIC_EnableIRQ(I2C1_IRQn);

/* USER CODE BEGIN I2C1_MspInit 1 */



/* USER CODE END I2C1_MspInit 1 */

}



}

/**************************************************************************************/

 

 

 

 

Configuration in the Master (STM32F042G4U6) working at 48MHz:

This node only sends a request every seconf to the slave, but i tried and with the HCLK in the slave set

to 8MHz, i can set any frequency in The Master and the comunication still works. But if

i modify the Slave frequency over 8MHz stop working as i commented before.

 

 

 

 

/**************************************************************************************/ 

static void MX_I2C1_Init(void) {



/* USER CODE BEGIN I2C1_Init 0 */



/* USER CODE END I2C1_Init 0 */



/* USER CODE BEGIN I2C1_Init 1 */



/* USER CODE END I2C1_Init 1 */

hi2c1.Instance = I2C1;

hi2c1.Init.Timing = 0x2000090E;

hi2c1.Init.OwnAddress1 = 0;

hi2c1.Init.AddressingMode = I2C_ADDRESSINGMODE_7BIT;

hi2c1.Init.DualAddressMode = I2C_DUALADDRESS_DISABLE;

hi2c1.Init.OwnAddress2 = 0;

hi2c1.Init.OwnAddress2Masks = I2C_OA2_NOMASK;

hi2c1.Init.GeneralCallMode = I2C_GENERALCALL_DISABLE;

hi2c1.Init.NoStretchMode = I2C_NOSTRETCH_DISABLE;

if (HAL_I2C_Init(&hi2c1) != HAL_OK) {

Error_Handler();

}



/** Configure Analogue filter

*/

if (HAL_I2CEx_ConfigAnalogFilter(&hi2c1, I2C_ANALOGFILTER_ENABLE)

!= HAL_OK) {

Error_Handler();

}



/** Configure Digital filter

*/

if (HAL_I2CEx_ConfigDigitalFilter(&hi2c1, 0) != HAL_OK) {

Error_Handler();

}

/* USER CODE BEGIN I2C1_Init 2 */



/* USER CODE END I2C1_Init 2 */



}

/**************************************************************************************/

void HAL_I2C_MspInit(I2C_HandleTypeDef* hi2c)

{

GPIO_InitTypeDef GPIO_InitStruct = {0};

if(hi2c->Instance==I2C1)

{

/* USER CODE BEGIN I2C1_MspInit 0 */



/* USER CODE END I2C1_MspInit 0 */



__HAL_RCC_GPIOB_CLK_ENABLE();

/**I2C1 GPIO Configuration

PB6 ------> I2C1_SCL

PB7 ------> I2C1_SDA

*/

GPIO_InitStruct.Pin = GPIO_PIN_6|GPIO_PIN_7;

GPIO_InitStruct.Mode = GPIO_MODE_AF_OD;

GPIO_InitStruct.Pull = GPIO_NOPULL;

GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_HIGH;

GPIO_InitStruct.Alternate = GPIO_AF1_I2C1;

HAL_GPIO_Init(GPIOB, &GPIO_InitStruct);



/* Peripheral clock enable */

__HAL_RCC_I2C1_CLK_ENABLE();

/* I2C1 interrupt Init */

HAL_NVIC_SetPriority(I2C1_IRQn, 0, 0);

HAL_NVIC_EnableIRQ(I2C1_IRQn);

/* USER CODE BEGIN I2C1_MspInit 1 */



/* USER CODE END I2C1_MspInit 1 */

}



}

/**************************************************************************************/

 

 

 

[Andrew Neil]

Use this button to properly post source code:

 

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[Swanduron]

I also have the same issue with I2C communication. My project includes AHT20 as the temperature sensor to read the environment status.

In the beginning, I successfully implemented the AHT20 communication under HAL_I2C_Receive/Transmit, under 72MHz HCLK. As the project has heavy workload in data conversion, I tried to use the HAL_I2C_Receive_IT/Transmit_IT to reduce the time lag in peripherals' communication.

But the only way to let the AHT20 work is by locking the HCLK to 8MHz. Any frequencies of HLCK are higher than 8MHz, whether it is the crystal or the internal generator, the system can't generate the interruption to be captured by the callback function. No way to resolve this issue till now.