Hello everyone:
I'm working with board NUCLEO-U031R8, and need to wake up when LPUART receive data which using LSE with 32768Hz.
MCU would send back the receive data which end with '\n', and it works fine in running mode, and a special command 'S' let MCU go into stop mode and wait next data, and send back receive data when wakeup.
The receive data length is correct while wakeup in stop mode, but the receive data is broken, and if has next command it will reply as normal, the communication like this:
And here is the sample code:
int main(void) {
/* Reset of all peripherals, Initializes the Flash interface and the Systick. */
HAL_Init();
/* Configure the system clock */
SystemClock_Config();
LL_RCC_LSE_EnablePropagation();
while(LL_RCC_LSE_IsPropagationReady() != 1);
/* Initialize all configured peripherals */
MX_GPIO_Init();
MX_LPUART1_UART_Init();
LL_LPUART_EnableIT_RXNE_RXFNE(LPUART1);
LL_LPUART_SetWKUPType(LPUART1, LL_LPUART_WAKEUP_ON_RXNE); // Set LPUART1->CR3.WUS to wake-up on RXNE
/* Infinite loop */
LPUART_SendStr("Start\r\n");
while (1)
{
if (rxFlag > 0) {
if (rxBuf[0] == 'S') { // check sleep command
// reset the receive data
rxFlag = 0;
rxIdx = 0;
LPUART_SendStr("Sleeping...\r\n");
LL_LPUART_EnableInStopMode(LPUART1); // Set LPUART1->CR1.UESM
LL_PWR_EnableLowPowerRunMode(); // Set PWR->CR1.LPR
LL_PWR_SetPowerMode(LL_PWR_MODE_STOP1); // Set PWR->CR1.LPMS
// ------------------ Sleep ------------------
SET_BIT(SCB->SCR, ((uint32_t)SCB_SCR_SLEEPDEEP_Msk));
__WFI();
CLEAR_BIT(SCB->SCR, ((uint32_t)SCB_SCR_SLEEPDEEP_Msk));
// -------------------------------------------
LL_PWR_DisableLowPowerRunMode(); // Clear PWR->CR1.LPR
LL_LPUART_DisableInStopMode(LPUART1); // Clear LPUART1->CR1.UESM
LL_mDelay(200); // delay for receive data compeleted
LPUART_Send(rxBuf, rxIdx); // send back the receive data
}
else {
// not Sleep command, send back the receive data
LPUART_Send(rxBuf, rxFlag);
}
rxFlag = 0;
rxIdx = 0;
}
LL_mDelay(100);
}
}
void USART3_LPUART1_IRQHandler(void)
{
if (LL_LPUART_IsActiveFlag_WKUP(LPUART1) && LL_LPUART_IsEnabledIT_WKUP(LPUART1)) {
LL_LPUART_DisableIT_WKUP(LPUART1);
LL_LPUART_ClearFlag_WKUP(LPUART1);
}
uint8_t ch = LL_LPUART_ReceiveData8(LPUART1);
rxBuf[rxIdx++] = ch;
if (ch == '\n') rxFlag = rxIdx;
}Anyone have any idea what's going on?
Regards.
