STM32 UART stops At High Temperature

[JThom.15]

Hi,

I am Using an stm32f205 on our board. All the Uarts works fine at room temperature. But when the temp increases above 58 degress, messages started get missed in the uarts or sometimes it completely stops sending messages.

I am running the board at 120MHZ Here is my clock setup 

RCC_OscInitTypeDef RCC_OscInitStruct = {0};

  RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSI;

  RCC_OscInitStruct.HSIState = RCC_HSI_ON;

  RCC_OscInitStruct.HSICalibrationValue = RCC_HSICALIBRATION_DEFAULT;

  RCC_OscInitStruct.PLL.PLLState = RCC_PLL_ON;

  RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_HSI;

  RCC_OscInitStruct.PLL.PLLM = 13;

  RCC_OscInitStruct.PLL.PLLN = 195;

  RCC_OscInitStruct.PLL.PLLP = RCC_PLLP_DIV2;

  RCC_OscInitStruct.PLL.PLLQ = 4;

  if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK)

  {

    Error_Handler();

  }

  RCC_ClkInitTypeDef RCC_ClkInitStruct = {0};

  RCC_ClkInitStruct.ClockType = RCC_CLOCKTYPE_HCLK | RCC_CLOCKTYPE_SYSCLK | RCC_CLOCKTYPE_PCLK1 | RCC_CLOCKTYPE_PCLK2;

  RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_PLLCLK;

  RCC_ClkInitStruct.AHBCLKDivider = RCC_SYSCLK_DIV1;

  RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV4;

  RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV2;

  if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_3) != HAL_OK)

  {

    Error_Handler();

  }

Any help would be much appreciated 

[TDK]

Looks like it averages to about +2% per 80 deg C. You could monitor the internal temp and adjust accordingly. Auto baud rate detection is also a possibility if you can listen before you speak.