Hello Here is my USART's settings:
USART_InitTypeDef USAR; GPIO_InitTypeDef GPIOStruc; RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOB |RCC_APB2Periph_AFIO,ENABLE); RCC_APB2PeriphClockCmd(RCC_APB2Periph_USART1,ENABLE); GPIO_PinRemapConfig(GPIO_Remap_USART1,ENABLE); GPIOStruc.GPIO_Mode=GPIO_Mode_AF_PP ; GPIOStruc.GPIO_Speed=GPIO_Speed_50MHz; GPIOStruc.GPIO_Pin=GPIO_Pin_6; GPIO_Init(GPIOB,&GPIOStruc); GPIOStruc.GPIO_Mode=GPIO_Mode_IN_FLOATING ; GPIOStruc.GPIO_Pin=GPIO_Pin_7; GPIO_Init(GPIOB,&GPIOStruc); USAR.USART_BaudRate=115200; USAR.USART_StopBits=USART_StopBits_1; USAR.USART_WordLength=USART_WordLength_8b; USAR.USART_Parity=USART_Parity_No ; USAR.USART_HardwareFlowControl=USART_HardwareFlowControl_None; USAR.USART_Mode=USART_Mode_Rx | USART_Mode_Tx; USART_Init(USART1,&USAR); USART_ITConfig(USART1,USART_IT_RXNE,ENABLE); NVIC_EnableIRQ(USART1_IRQn); USART_Cmd(USART1,ENABLE);
and I send 200 characters with printf function each 20ms(that created by timer).
timer settings
TIM_TimeBaseInitTypeDef TimeStruct; NVIC_InitTypeDef nvicStructure; nvicStructure.NVIC_IRQChannel = TIM2_IRQn; nvicStructure.NVIC_IRQChannelPreemptionPriority = 0; nvicStructure.NVIC_IRQChannelSubPriority = 1; nvicStructure.NVIC_IRQChannelCmd = ENABLE; NVIC_Init(&nvicStructure); RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2,ENABLE); TimeStruct.TIM_Prescaler=7200; TimeStruct.TIM_Period=200; TimeStruct.TIM_ClockDivision=TIM_CKD_DIV1; TimeStruct.TIM_CounterMode= TIM_CounterMode_Up ; TimeStruct.TIM_RepetitionCounter =0; TIM_TimeBaseInit(TIM2, &TimeStruct); TIM_Cmd(TIM2, ENABLE); TIM_ITConfig(TIM2,TIM_IT_Update,ENABLE);
printf("LOng string......");
struct __FILE { int handle;} ; FILE __stdout; FILE __stdin; FILE __stderr; int fputc(int ch, FILE *f) { while(!USART_GetFlagStatus(USART1,USART_FLAG_TXE)); USART_SendData(USART1,ch); return ch;
but when I send a 120 characters string to my device it doesn't do anything
void USART1_IRQHandler(void){ if (USART_GetITStatus(USART1, USART_IT_RXNE) != RESET) { temp=USART_ReceiveData(USART1); } }
but when I increase timer step (for example 100ms) it works fine. what's wrong with it ? what is my mistake?
char buf1[BUFSIZE]; char buf2[BUFSIZE]; volatile unsigned delivered_msg_size = 0; volatile char *delivered_msg = NULL; volatile char *tmp_msg = buf1; void loop() { for (;;) { if (delivered_msg) { process_msg(delivered_msg,delivered_msg_size); delivered_msg = NULL; } ... } } void uart_irq() { static unsigned insert_pos = 0; static unsigned in_packet = FALSE; ... if (c == START_CHAR) { insert_pos = 0; in_packet = TRUE; } else if (!in_packet) { // ignore char } else if (c == END_CHAR) { if (delivered_msg) { // main loop hasn't processed data fast enough... // throw away this new packet! } else { delivered_msg_size = insert_pos; delivered_msg = tmp_msg; tmp_msg = (tmp_msg == buf1) ? buf2 : buf1; } in_packet = FALSE; } else if (!valid_char(c)) { // invalid data - fail packet in_packet = FALSE; } else if (insert_pos >= BUFSIZE) { // too much data - fail packet in_packet = FALSE; } else { tmp_msg[insert_pos++] = c; } ... }
Reserve one additional position in the buffer and zero-terminate just before hand-over, in case you want the final buffer to be zero-terminated so you can directly print it.
Then you can also decide to not hand over any message size.
Thanks a zillion for you masterfully code Actually I've changed my received code and it works better but still missing characters exist it seems it is related to timer code and it's output and " if(dat!=0){break;}" didn't prevent from this problem
Make use of UART transmit interrupts to send.
If each message to send should differ, then have the main loop create the strings.
Let the timer interrupt activate the UART transmission - the UART ISR will then pick up new characters as they are consumed. When the last character has transmitted, then turn off the UART TX interrupt and leave off until the timer ISR kick-starts the next transmission.
With a quick timer ISR, you get less latency issues from concurrently pending interrupt sources.
Hurraa... Thank you Per Westermark Now it works fine with USART transmit interrupts. Thanks a zillion for accompany me and your good explanation