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marwen_azouzi
Associate II
May 3, 2012
Question

stm32VL UART problem

  • May 3, 2012
  • 11 replies
  • 2004 views
Posted on May 03, 2012 at 03:14

Hi

i have to communicate with modem using uart via AT command

my pb is when i send the first command and receive the reponse i can't send the next AT using uart

i can post my code if any one can help me 

#uart #adc-stm32-discovery
This topic has been closed for replies.

11 replies

marwen_azouzi
Associate II
May 3, 2012
Posted on May 03, 2012 at 03:28

Tesla DeLorean
Guru
May 3, 2012
Posted on May 03, 2012 at 04:21

#include ''stm32f10x.h''
#include ''STM32vldiscovery.h''
#include ''stm32f10x_gpio.h''
void RCC_Configuration(void);
void GPIO_Configuration(void);
void NVIC_Configuration(void);
void SendString(char *s)
{
while(*s)
{
while(USART_GetFlagStatus(USART1, USART_FLAG_TXE) == RESET);
USART_SendData(USART1, *s++);
}
}
int main(void)
{
USART_InitTypeDef USART_InitStructure;
/* System Clocks Configuration */
RCC_Configuration();
/* NVIC configuration */
//NVIC_Configuration();
/* Configure the GPIO ports */ 
GPIO_Configuration();
/* 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( USART1,&USART_InitStructure);
/* You might want some delays between these,
I'm just illustrating how to transmit to the USART
with a subroutine */
SendString(''AT?
'');
SendString(''ATB
'');
while(1)
{
}
}
void RCC_Configuration(void)
{
/* Enable GPIO clock */
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA, ENABLE);
/* Enable USART2 Clock */
RCC_APB2PeriphClockCmd(RCC_APB2Periph_USART1, ENABLE);
/* Setup the microcontroller system. Initialize the Embedded Flash Interface, 
initialize the PLL and update the SystemFrequency variable. */
}
void GPIO_Configuration(void)
{
GPIO_InitTypeDef GPIO_InitStructure;
/* Configure USART1 Rx as input floating */
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_10;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;
GPIO_Init(GPIOA,&GPIO_InitStructure);
/* Configure USART1 Tx as alternate function push-pull */
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_9;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
GPIO_Init(GPIOA,&GPIO_InitStructure);
}
#ifdef USE_FULL_ASSERT
/**
* @brief Reports the name of the source file and the source line number
* where the assert_param error has occurred.
* @param file: pointer to the source file name
* @param line: assert_param error line source number
* @retval None
*/
void assert_failed(uint8_t* file, uint32_t line)
{ 
/* User can add his own implementation to report the file name and line number,
ex: printf(''Wrong parameters value: file %s on line %d

'', file, line) */
/* Infinite loop */
while (1)
{
}
}
#endif

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marwen_azouzi
Associate II
May 4, 2012
Posted on May 04, 2012 at 02:37

thx using fct to send is an easy way 

in your opinion  for the reception I had to use  interrupt or just polling mode 

i must compare the Inbuffer to send other AT command
Tesla DeLorean
Guru
May 4, 2012
Posted on May 04, 2012 at 16:24

in your opinion  for the reception I had to use  interrupt or just polling mode 

 

i must compare the Inbuffer to send other AT command.

There are a number of ways of doing it, I personally use interrupts, and FIFO (ring) buffers on both the receive and transmit side.
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marwen_azouzi
Associate II
May 4, 2012
Posted on May 04, 2012 at 18:22

One little thing in case of using interrupt after receiving data from modem i must compare the reponse with the true one

so i have to clear Rxbuffer after each reception ? 
Tesla DeLorean
Guru
May 4, 2012
Posted on May 04, 2012 at 18:58

One little thing in case of using interrupt after receiving data from modem i must compare the reponse with the true one so i have to clear Rxbuffer after each reception ?

 

In a robust solution, you'll need to parse the responses, different modems respond differently, and you might get unexpected responses. Typically you'd be looking for ''OK'', ''ERROR'', ''NO CARRIER'', etc.
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marwen_azouzi
Associate II
May 8, 2012
Posted on May 09, 2012 at 00:57

Hi again

I use for the comparaison the function ''buffercmp'' which compaire 2 buffer as result ''FAILED'' or ''PASSED'' i want a way which after the comparaison to clear the Rxbuffer  
Tesla DeLorean
Guru
May 9, 2012
Posted on May 09, 2012 at 02:31

I use for the comparaison the function ''buffercmp'' which compaire 2 buffer as result ''FAILED'' or ''PASSED'' i want a way which after the comparaison to clear the Rxbuffer

While I think this is a rather sloppy approach, what you're suggesting would look like this :

// Receive enough to evaluate...
if (Buffercmp(RxBuffer, ''ERROR'', RxCounter) == PASSED)
puts(''Modem returned ERROR!'');
RxCounter = 0; // Clear RxBuffer to beginning

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marwen_azouzi
Associate II
May 9, 2012
Posted on May 09, 2012 at 04:18

which the best way so in your opinion

i have multiple reception for each reception i must compare and send the suitable command
rasimoguzturk
Associate III
October 4, 2012
Posted on October 04, 2012 at 13:51

hi,i am recently working on a project that sending AT command to gsm module from stm32f100c8  via usart and receiving response with interrupt but i am very confused about usart interfaces.i cant receive response from gsm module.i am using stm32vl discovery and ublox leon g100 gsm module usart1 and usart3 and terminal.It sends me back same string.i send ''AT'' and i want to get ''OK'' response from module.please help where am i wrong?here is my code :

/*----------------------------------------------*/

/*----------------------------------------------*/

#include ''stm32f10x.h''

#include ''stdio.h''

#include ''string.h''

/*----------------------------------------------*/

/*---------function prototypes------------------*/

void RCC_Configuration(void);

void GPIO_Configuration(void);

void NVIC_Configuration(void);

void USART_Configuration(void);

void ResetModule(void);

void USART_SendCommand(unsigned char *s);

/*------------------------------------------------*/

/*-------------global variables-------------------*/

unsigned char command[]=''AT\0\r\n'';

char response[50];

int res_index=0;

unsigned char r;

/*----------------------------------------------*/

/*----------RCC configurations------------------*/

void RCC_Configuration(void){

RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA, ENABLE);

RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOB, ENABLE);

RCC_APB2PeriphClockCmd(RCC_APB2Periph_USART1, ENABLE);

RCC_APB1PeriphClockCmd(RCC_APB1Periph_USART3, ENABLE);

}

/*----------------------------------------------*/

/*----------GPIO configurations------------------*/

void GPIO_Configuration(void){

GPIO_InitTypeDef GPIO_InitStructure;

/* Configuring USART1_Tx as 'alternate function push-pull' */

GPIO_InitStructure.GPIO_Pin = GPIO_Pin_9;

GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;

GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;

GPIO_Init(GPIOA, &GPIO_InitStructure);

/* Configuring USART1_Rx as 'input floating' */

GPIO_InitStructure.GPIO_Pin = GPIO_Pin_10;

GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;

GPIO_Init(GPIOA, &GPIO_InitStructure);

/* Configuring USART3_Tx as 'alternate function push-pull' */

GPIO_InitStructure.GPIO_Pin = GPIO_Pin_10;

GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;

GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;

GPIO_Init(GPIOB, &GPIO_InitStructure);

/* Configuring USART3_Rx as 'input floating' */

GPIO_InitStructure.GPIO_Pin = GPIO_Pin_11;

GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;

GPIO_Init(GPIOB, &GPIO_InitStructure);

/* reset the module*/

GPIO_InitStructure.GPIO_Pin = GPIO_Pin_12 | GPIO_Pin_13;

GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;

GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_PP;

GPIO_Init(GPIOB, &GPIO_InitStructure );

}

/*----------------------------------------------*/

/*----------USART configurations----------------*/

void USART_Configuration(void){

USART_InitTypeDef USART_InitStructure;

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_Mode = USART_Mode_Rx | USART_Mode_Tx;

USART_InitStructure.USART_HardwareFlowControl = USART_HardwareFlowControl_None;

USART_Init(USART1, &USART_InitStructure);

USART_Cmd(USART1, ENABLE);

USART_Init(USART3, &USART_InitStructure);

USART_Cmd(USART3, ENABLE);

USART_ITConfig(USART3, USART_IT_RXNE, ENABLE);

}

/*----------------------------------------------*/

/*----------NVIC configurations-----------------*/

void NVIC_Configuration(void){

NVIC_InitTypeDef NVIC_InitStructure;

NVIC_InitStructure.NVIC_IRQChannel = USART3_IRQn;

NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;

NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;

NVIC_Init(&NVIC_InitStructure);

}

/*----------------------------------------------*/

/*----------RESET module-----------*/

void ResetModule(void){

long int n;

//reset 

GPIO_SetBits(GPIOB,GPIO_Pin_13);

for(n = 0;n < 10000000;n++); 

GPIO_ResetBits(GPIOB,GPIO_Pin_13);

for(n = 0;n < 30000000;n++);

//power

GPIO_SetBits(GPIOB,GPIO_Pin_12);

for(n = 0;n < 10000000;n++);

GPIO_ResetBits(GPIOB,GPIO_Pin_12);

}

/*----------------------------------------------*/

/*----------Main function-----------------------*/

int main(){

RCC_Configuration();

GPIO_Configuration();

USART_Configuration();

NVIC_Configuration();

ResetModule();

USART_SendCommand(command);

while(1){

}

}

/*----------------------------------------------*/

/*----------Send command------------------------*/

void USART_SendCommand(unsigned char *s)

{

while(*s)

{

//while(USART_GetFlagStatus(USART1, USART_FLAG_TXE) == RESET);

//USART_SendData(USART1, *s);

while(USART_GetFlagStatus(USART3, USART_FLAG_TXE) == RESET);

USART_SendData(USART3, *s++);

}

}

/*----------------------------------------------*/

/*----------Receive character from USART3-------*/

void USART3_IRQHandler(void){ 

r=USART_ReceiveData(USART3);

response[res_index]=r;

res_index++;

}

/*----------------------------------------------*/

/*--------------------------------------------------------------------------------------------*/

/*--------------------------------------------------------------------------------------------*/

/*--------------------------------------------------------------------------------------------*/

/*--------------------------------------------------------------------------------------------*