Posted on October 02, 2015 at 23:18Hi guys, I have a problem. I have a USB-RS232 converter and i'll do usart tutorial with STM32F4. Codes are working, but meaningless character viewing at the serial Hyper terminal program.
Baudrate 9600.
Clock Configuration: HSE_VALUE=8000000 and PLL_M=8 as defined. But don't working. There are still meaningless characters.
my problem is here :
http://s23.postimg.org/mbz2h0xm3/2015_10_03_00_05_57_Ekran_g_r_nt_s.png
I would be glad if you can help..
My code is here:
/*
USART2 example, with IRQ
I am using a CP2102 USB-to-USART converter.
Wiring connections:
STM32F4 CP2102
PA2 (USART2 Tx) -> Rx
PA3 (USART2 Rx) -> Tx
*/
#include <stdio.h>
#include ''stm32f4xx.h''
char str[50];
volatile uint32_t msTicks; /* counts 1ms timeTicks */
void SysTick_Handler(void) {
msTicks++;
}
// Delays number of Systicks (happens every 1 ms)
static void Delay(__IO uint32_t dlyTicks){
uint32_t curTicks = msTicks;
while ((msTicks - curTicks) < dlyTicks);
}
void setSysTick(){
// ---------- SysTick timer (1ms) -------- //
if (SysTick_Config(SystemCoreClock / 1000)) {
// Capture error
while (1){};
}
}
void setup_Periph(){
GPIO_InitTypeDef GPIO_InitStructure;
USART_InitTypeDef USART_InitStructure;
NVIC_InitTypeDef NVIC_InitStructure;
// Enable the APB1 periph clock for USART2
RCC_APB1PeriphClockCmd(RCC_APB1Periph_USART2, ENABLE);
// Enable the GPIOA clock, used by pins PA2, PA3
RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOA, ENABLE);
// Setup the GPIO pins for Tx and Rx
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_2 | GPIO_Pin_3;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP;
GPIO_Init(GPIOA, &GPIO_InitStructure);
// Connect PA2 and PA3 with the USART2 Alternate Function
GPIO_PinAFConfig(GPIOA, GPIO_PinSource2, GPIO_AF_USART2);
GPIO_PinAFConfig(GPIOA, GPIO_PinSource3, GPIO_AF_USART2);
USART_InitStructure.USART_BaudRate = 9600;
USART_InitStructure.USART_WordLength = USART_WordLength_8b;
USART_InitStructure.USART_StopBits = USART_StopBits_1;
USART_InitStructure.USART_Parity = USART_Parity_No;
USART_InitStructure.USART_HardwareFlowControl = USART_HardwareFlowControl_None;
USART_InitStructure.USART_Mode = USART_Mode_Tx | USART_Mode_Rx;
USART_Init(USART2, &USART_InitStructure);
/* Enable the USART2 receive interrupt and configure
the interrupt controller to jump to USART2_IRQHandler()
if the USART2 receive interrupt occurs
*/
USART_ITConfig(USART2, USART_IT_RXNE, ENABLE);
NVIC_InitStructure.NVIC_IRQChannel = USART2_IRQn;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStructure);
// Finally enable the USART2 peripheral
USART_Cmd(USART2, ENABLE);
}
void USART_puts(USART_TypeDef *USARTx, volatile char *str){
while(*str){
// Wait for the TC (Transmission Complete) Flag to be set
// while(!(USARTx->SR & 0x040));
while(USART_GetFlagStatus(USART2, USART_FLAG_TC) == RESET);
USART_SendData(USARTx, *str);
*str++;
}
}
int main(void) {
setSysTick();
setup_Periph();
sprintf(str,''MAHMUT'');
USART_puts(USART2, str);
while(1){
// Nothing done here since we are using interrupts
}
return 0;
}
