OS::channel<uint8_t, 32> UsartRxChannel;
....
extern "C" void USART1_IRQHandler(void)
{
  if(USART_GetITStatus(USART1, USART_IT_RXNE) != RESET)
  {
    uint8_t c;
    c = USART1->DR;
    if (UsartRxChannel.get_free_size()>0) UsartRxChannel.push(c);    
  }
}

extern "C" void USART1_IRQHandler(void)
{
    if(USART_GetITStatus(USART1, USART_IT_RXNE) != RESET)
    {
        OS::TISRW ISR;
...

{
    auto status = USART1->SR;
    auto data = USART1->DR;

    if (status & USART_FLAG_RXNE)
    {
        if (rxChannel_.get_free_size())
            rxChannel_.push(data);
    }
...

struct sFifo
{
uint8_t buf[128];
uint8_t tail;
uint8_t head;
uint8_t MsgSize;
};
sFifo usartRXfifo;
OS::TEventFlag GpsFlag;
extern "C" void USART1_IRQHandler(void)
{
OS::TISRW ISR;
auto status = USART1->SR;
auto data = USART1->DR;
if (status & USART_FLAG_RXNE)
{
if((usartRXfifo.head-usartRXfifo.tail)!=128)
{
usartRXfifo.buf[usartRXfifo.head & 0x7F]=data;
usartRXfifo.head++;
}
if (data=='\r')
{
usartRXfifo.MsgSize = usartRXfifo.head-usartRXfifo.tail;
GpsFlag.signal_isr();
}
}
}

// If the macro value is 0 (the default), the port uses SysTick as a system
// timer. It initializes the timer and starts it. The user must make sure that
// the address of the timer interrupt handler (SysTick_Handler) is in the right
// place at the interrupt vector table.
// If the macro value is 1, then the user has to implement (see docs for details):
// 1. extern "C" void __init_system_timer();
// 2. void LOCK_SYSTEM_TIMER() / void UNLOCK_SYSTEM_TIMER();
// 3. In the interrupt handler of the custom timer, the user needs to call
// OS::system_timer_isr()

#if SCMRTOS_USE_CUSTOM_TIMER == 1

static void TIM3_Event()
{
OS::system_timer_isr();
}

extern "C" void __init_system_timer()
{
RCC_BASE->APB1ENR |= RCC_APB1ENR_TIM3EN; // TIM3
// TIM3 master counter period 1 msec 48MHz main
TIMER3->regs.gen->CR1 &= ~TIMER_CR1_CEN; // disabled
TIMER3->regs.gen->PSC = 480 - 1; //new clock = 100kHz
TIMER3->regs.gen->ARR = 100 - 1; //period = 16usec
TIMER3->regs.gen->CR1 |= TIMER_CR1_DIR; //used as downcounter
timer_attach_interrupt(TIMER3, TIMER_UPDATE_INTERRUPT, TIM3_Event);
TIMER3->regs.gen->CR1 |= TIMER_CR1_CEN; // enable timer
TIMER3->regs.gen->DIER |= TIMER_DIER_UIE; //enable interrupt
}

INLINE void LOCK_SYSTEM_TIMER()
{
TIMER3->regs.gen->CR1 &= ~TIMER_CR1_CEN; // disable timer
}

INLINE void UNLOCK_SYSTEM_TIMER()
{
TIMER3->regs.gen->CR1 |= TIMER_CR1_CEN; // enable timer
}


#endif