Posted on September 01, 2014 at 13:25I have a STM32F405RG with external 16MHz crystal which is also used, divided by 16 as the RTC clock source. The project has been built using VisualGDB.
The problem is that the RTC appears to stop after it is read. I have reduced the code down to a minimum to investigate this problem. If put a breakpoint on the first read then wait a known length of time the clock reads OK and the elapsed time is correct. Subsequent reads show the same time.
The code is shown below. Any ideas what is happening?
RTC_TimeTypeDef sTime;
RTC_DateTypeDef sDate;
RTC_HandleTypeDef hrtc;
&sharpifdef __cplusplus
extern ''C''
&sharpendif
void SysTick_Handler(void)
{
HAL_IncTick();
}
int main(void)
{
HAL_Init();
init_clocks();
init_Gpio();
HAL_RTC_GetTime(&hrtc, &sTime, FORMAT_BCD);
while (1)
{
HAL_GPIO_TogglePin(EVENT_PORT, EVENT_LED_PIN);
HAL_Delay(500);
HAL_RTC_GetTime(&hrtc, &sTime, FORMAT_BCD);
}
}
void init_clocks(void)
{
RCC_ClkInitTypeDef RCC_ClkInitStruct;
RCC_PeriphCLKInitTypeDef PeriphClkInitStruct;
RCC_OscInitTypeDef RCC_OscInitStruct;
PeriphClkInitStruct.PeriphClockSelection = RCC_PERIPHCLK_RTC;
PeriphClkInitStruct.RTCClockSelection = RCC_RTCCLKSOURCE_HSE_DIV16;
HAL_RCCEx_PeriphCLKConfig(&PeriphClkInitStruct);
__HAL_RCC_RTC_ENABLE();
__PWR_CLK_ENABLE();
__HAL_PWR_VOLTAGESCALING_CONFIG(PWR_REGULATOR_VOLTAGE_SCALE1);
RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSE;
RCC_OscInitStruct.HSEState = RCC_HSE_ON;
RCC_OscInitStruct.PLL.PLLState = RCC_PLL_ON;
RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_HSE;
RCC_OscInitStruct.PLL.PLLM = 16;
RCC_OscInitStruct.PLL.PLLN = 320;
RCC_OscInitStruct.PLL.PLLP = RCC_PLLP_DIV2;
RCC_OscInitStruct.PLL.PLLQ = 4;
HAL_RCC_OscConfig(&RCC_OscInitStruct);
RCC_ClkInitStruct.ClockType = 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;
HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_5);
hrtc.Instance = RTC;
hrtc.Init.HourFormat = RTC_HOURFORMAT_24;
hrtc.Init.AsynchPrediv = 124;
hrtc.Init.SynchPrediv = 7999;
hrtc.Init.OutPut = RTC_OUTPUT_DISABLE;
hrtc.Init.OutPutPolarity = RTC_OUTPUT_POLARITY_HIGH;
hrtc.Init.OutPutType = RTC_OUTPUT_TYPE_OPENDRAIN;
HAL_RTC_Init(&hrtc);
sTime.Hours = 1;
sTime.Minutes = 1;
sTime.Seconds = 1;
sTime.SubSeconds = 0;
sTime.TimeFormat = RTC_HOURFORMAT_24;
sTime.DayLightSaving = RTC_DAYLIGHTSAVING_NONE;
sTime.StoreOperation = RTC_STOREOPERATION_RESET;
HAL_RTC_SetTime(&hrtc, &sTime, FORMAT_BCD);
sDate.WeekDay = RTC_WEEKDAY_MONDAY;
sDate.Month = RTC_MONTH_JANUARY;
sDate.Date = 1;
sDate.Year = 0;
HAL_RTC_SetDate(&hrtc, &sDate, FORMAT_BCD);
}
void init_Gpio(void)
{
GPIO_InitTypeDef GPIO_InitStruct;
__GPIOB_CLK_ENABLE();
GPIO_InitStruct.Pin = EVENT_LED_PIN | EVENT1_LED_PIN;
GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;
GPIO_InitStruct.Speed = GPIO_SPEED_HIGH;
GPIO_InitStruct.Pull = GPIO_NOPULL;
HAL_GPIO_Init(GPIOB, &GPIO_InitStruct);
}
#stm32f4 #rtc #visualgdb
