Using TIM6 and TIM2 in STM32f407 Discovery board: DHT11 sensor and CAN frames

[Azizz]

Hello everyone,

I'm using the STM32f407 Discovery board.
I'm trying to use TIM2 to send a frame in a cyclic way and also i'm using TIM6 to send the data of a DHT11 sensor. The problem is that when i added the TIM6 i no longer receiver the frames.
Who should i adjust my code in order to work with the DHT11 sensor data and still send my frames.
I tried to use the DHT11 sensor separately to make sure that the code works and it works perfectly.

[mƎALLEm]

Hello,

First, could you please state on this thread? if the provided answer solved your issue please accept it as solution.

Second, 

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@Azizz wrote:

The problem is that when i added the TIM6 i no longer receiver the frames.

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Which frame? CAN frames? if yes from which node?

[Azizz]

The problem occurs in these lines 

  if (HAL_TIM_Base_Start_IT(&htim2) != HAL_OK)
   {
     Error_Handler();
  }

  HAL_TIM_OC_Start_IT(&htim2, TIM_CHANNEL_1);

I cannot send any frame neither the cyclic one or the frame sent by request.

[Andrew Neil]

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@Azizz wrote:

The problem occurs in these lines 

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What problem occurs, exactly?

Does it hit the Error-Handler ?

If so, look at what value HAL_TIM_Base_Start_IT returned; step into it to find why ...

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@Azizz wrote:

when i added the TIM6 i no longer receiver the frames.

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Is that because nothing is transmitted at all, or the transmission becomes "bad"?

If "bad", in what way(s) is it bad?

PS:

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@Azizz wrote:

I'm trying to use TIM2 to send a frame in a cyclic way and also i'm using TIM6 to send the data of a DHT11 sensor. The problem is that when i added the TIM6 i no longer receiver the frames.

---

If you just start TIM6 without doing any DHT11 stuff, are the [CAN?] frames still OK

ie, is it the timer itself, or something else in your DHT11 code that's causing the problem?

[Azizz]

It is not transmitted at all and when i remove these lines the program works but the frame is no longer send cyclically.
It doesn't hit he error handler when i try to use the step over button in the line showed below, it blocks the program.

  if (HAL_TIM_Base_Start_IT(&htim2) != HAL_OK)

[Azizz]

Yess when i remove the line commented i receive the frames

void Send_Cyclic_Frame_A (void) {
	uint8_t temp = 0, humi = 0;

    //DHT11_GetData(&temp, &humi);

	TxHeader.StdId = 0x103;
	TxHeader.RTR = CAN_RTR_DATA;
	TxHeader.IDE = CAN_ID_STD;
	TxHeader.DLC = 2;
	TxHeader.TransmitGlobalTime = DISABLE;

	TxData[0] = temp;
	TxData[1] = humi;

	if (HAL_CAN_AddTxMessage(&hcan1, &TxHeader, TxData, &TxMailbox)!= HAL_OK )
	{
		   Error_Handler();
	}
}

[Andrew Neil]

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@Azizz wrote:

 when i try to use the step over button in the line showed below, it blocks the program.

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So step into that function to see where & why it blocks ...

[Andrew Neil]

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@Azizz wrote:

Yes when i remove the line commented i receive the frames

void Send_Cyclic_Frame_A (void) {
   uint8_t temp = 0, humi = 0;

   //DHT11_GetData(&temp, &humi);

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So look into what's happening within that DHT11_GetData() function...

Is it blocking?

[Azizz]

Inside the DHT11_GetData() i call the function 

uint8_t DHT11_Check_Response(void) {
    delay_us(40);
    if (!(HAL_GPIO_ReadPin(DHT11_PORT, DHT11_PIN))) {
        delay_us(80);
        if ((HAL_GPIO_ReadPin(DHT11_PORT, DHT11_PIN))) {
            delay_us(50);
            return 1;
        }
    }
    return 0;
}

I think the problem comes from the use of delay_us() or HAL_delay but i don't know how to replace them with an alternative

[Andrew Neil]

So that function will block for at least 40us, up to  a maximum of 170us.

If you just put such a delay into your  Send_Cyclic_Frame_A  function, does that show the same symptoms?

PS:

How is your delay_us implemented?