Problem with USART3 and Systick

[arielivandiaz]

Posted on November 22, 2014 at 07:04

I can't send information using USART3 when I use the SysTick.I don't know what i can do to fix.

/* Includes ------------------------------------------------------------------*/
#include ''stm32f4xx_gpio.h''
#include ''stm32f4xx_rcc.h''
#include ''stm32f4xx_usart.h''
#include<stdio.h>
#include <stdlib.h>
#include <string.h>
/**************************************************************************************/
void
RCC_Configuration(
void
)
{
/* --------------------------- System Clocks Configuration -----------------*/
/* USART3 clock enable */
RCC_APB1PeriphClockCmd(RCC_APB1Periph_USART3, ENABLE);
/* GPIOB clock enable */
RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOD, ENABLE);
}
/**************************************************************************************/
void
GPIO_Configuration(
void
)
{
GPIO_InitTypeDef GPIO_InitStructure;
/*-------------------------- GPIO Configuration ----------------------------*/
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_8 | GPIO_Pin_9;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;
GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_Init(GPIOD, &GPIO_InitStructure);
/* Connect USART pins to AF */
GPIO_PinAFConfig(GPIOD, GPIO_PinSource8, GPIO_AF_USART3);
GPIO_PinAFConfig(GPIOD, GPIO_PinSource9, GPIO_AF_USART3);
}
/**************************************************************************************/
void
USART3_Configuration(
void
)
{
USART_InitTypeDef USART_InitStructure;
/* USARTx configuration ------------------------------------------------------*/
/* USARTx configured as follow:
- BaudRate = 9600 baud
- Word Length = 8 Bits
- Two Stop Bit
- Odd parity
- Hardware flow control disabled (RTS and CTS signals)
- Receive and transmit enabled
*/
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_Rx | USART_Mode_Tx;
USART_Init(USART3, &USART_InitStructure);
USART_Cmd(USART3, ENABLE);
}
void
send_data(uint16_t n, 
char
*arr){
uint16_t i=0;
while
(i<n){
while
(USART_GetFlagStatus(USART3, USART_FLAG_TXE) == RESET){} 
// Espera que el registro de transmision este libre
USART_SendData(USART3, arr[i]); 
// Envia un caracter
i++;
}
while
(USART_GetFlagStatus(USART3, USART_FLAG_TXE) == RESET){} 
// Espera que el registro de transmision este libre
USART_SendData(USART3, 
'\n'
); 
// Envia un caracter
while
(USART_GetFlagStatus(USART3, USART_FLAG_TXE) == RESET){} 
// Espera que el registro de transmision este libre
USART_SendData(USART3, 
'\r'
); 
// Envia un caracter
}
/**************************************************************************************/
int
main(
void
)
{
setvbuf
( stdout, 0, _IONBF, 0 );
RCC_Configuration();
GPIO_Configuration();
USART3_Configuration();
char
buff[50]={
'\b'
};
uint16_t Data_rec;
SysTick_Config((SystemCoreClock/3.125) / 1000000); 
//Here is the problem
while
(1)
{
sprintf
(buff,
'' %d,%d ''
, 88 ,55 );
send_data(7,buff); 
if
(USART_GetFlagStatus(USART3, USART_FLAG_RXNE) != RESET) 
// Si se encuentra un dato disponible lo leo con la siguiente línea
Data_rec = USART_ReceiveData(USART3); 
// Recibe un caracter
}
}

#stm32f4 #usart #systick

[Tesla DeLorean]

Posted on November 22, 2014 at 14:10

I can't send information using USART3 when I use the SysTick. I don't know what i can do to fix.

So what does your SysTick interrupt code look like? When you're in the debugger, where does it end up? What does that suggest about the failure?