usart1 configuration

[louati-amir]

Posted on June 24, 2013 at 00:00

I wrote this program whitch send what it receive and each time it toggel the 4 leds in the board !

when i'm debugging the program don't catch the receive interruption !

#include ''stm32f4xx.h''

#include ''stm32f4xx_gpio.h''

#include ''stm32f4xx_rcc.h''

#include ''stm32f4xx_tim.h''

#include ''misc.h''

#include ''stm32f4xx_exti.h''

#include ''stm32f4xx_syscfg.h''

#include ''stm32f4xx_dma.h''

#include ''stm32f4xx_i2c.h''

#include ''stm32f4xx_usart.h''



void UART_Config(){

GPIO_InitTypeDef GPIO_InitStruct;

USART_InitTypeDef USART_InitStruct;

NVIC_InitTypeDef NVIC_InitStructure;


RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOB, ENABLE);

GPIO_InitStruct.GPIO_Pin = GPIO_Pin_6 | GPIO_Pin_7;

GPIO_InitStruct.GPIO_Mode = GPIO_Mode_AF;

GPIO_InitStruct.GPIO_Speed = GPIO_Speed_50MHz;

GPIO_InitStruct.GPIO_OType = GPIO_OType_PP;

GPIO_InitStruct.GPIO_PuPd = GPIO_PuPd_NOPULL;

GPIO_Init(GPIOB, &GPIO_InitStruct);


GPIO_PinAFConfig(GPIOB,GPIO_PinSource6,GPIO_AF_USART1);//TX

GPIO_PinAFConfig(GPIOB,GPIO_PinSource7,GPIO_AF_USART1);//RX


RCC_APB2PeriphClockCmd(RCC_APB2Periph_USART1, ENABLE); 

USART_InitStruct.USART_BaudRate = 9600;

USART_InitStruct.USART_HardwareFlowControl = USART_HardwareFlowControl_None;

USART_InitStruct.USART_Mode = USART_Mode_Rx | USART_Mode_Tx;

USART_InitStruct.USART_Parity = USART_Parity_No;

USART_InitStruct.USART_StopBits = USART_StopBits_1;

USART_InitStruct.USART_WordLength = USART_WordLength_8b;

USART_Init(USART1,&USART_InitStruct);


NVIC_InitStructure.NVIC_IRQChannel = USART1_IRQn;

NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0x0F;

NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0x0F;

NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;

NVIC_Init(&NVIC_InitStructure);


USART_Cmd(USART1,ENABLE);

}


void GPIO_Configuration(void)

{ 

/* GPIOD clock enable */

RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOD, ENABLE);


GPIO_InitTypeDef GPIO_InitStructure;


GPIO_InitStructure.GPIO_Pin = GPIO_Pin_12 | GPIO_Pin_13 | GPIO_Pin_14 | GPIO_Pin_15;

GPIO_InitStructure.GPIO_Mode = GPIO_Mode_OUT;

GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;

GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL;

GPIO_InitStructure.GPIO_Speed = GPIO_Speed_100MHz;

GPIO_Init(GPIOD, &GPIO_InitStructure);

}


uint16_t a;


void USART1_IRQHandler(void){

USART_ClearITPendingBit(USART1,USART_IT_RXNE);

GPIO_ToggleBits(GPIOD, GPIO_Pin_12 | GPIO_Pin_13 | GPIO_Pin_14 | GPIO_Pin_15);

a=USART_ReceiveData(USART1);

USART_SendData(USART1,a);

}


void main(){

I2C_Config();

UART_Config();

GPIO_Configuration();

while(1){

}

}

[Tesla DeLorean]

Posted on June 24, 2013 at 01:00

USART_ITConfig(USART1, USART_IT_RXNE, ENABLE);

Also you shouldn't need to explicitly clear the IT flag, as reading the data register will clear it.

[louati-amir]

Posted on June 24, 2013 at 07:47

It's working now :) but their is a problem of simpling the data it's lock like that the clock is not set rihght in fact it was configurated as 25Mhz so I generate a new ''system_stm32f4xx.c'' file using ''STM32F4xx_Clock_Configuration_V1.0.1.xls'' to change it to external 8 Mhz and I replaced the old one by this ! but it didn't work the problem of simpling data is always present :\

[Tesla DeLorean]

Posted on June 24, 2013 at 15:03

The project would need to be defining HSE_VALUE correctly to reflect the speed of the external crystal (HSE) being used.

[louati-amir]

Posted on June 24, 2013 at 16:37

I'm using IAR6.5 .

I tried to run my code in a template delivred by stm32 for the discovery board witch the clock and every thing is well configurated !

but the same problem is always present : wrong characters send back !

[Tesla DeLorean]

Posted on June 24, 2013 at 16:51

Then consider how it is connected. The STM32 cannot directly drive RS232 levels.

Observe signal with a scope, verify data and bit timing.

[louati-amir]

Posted on June 24, 2013 at 17:05

ok I will do that