Posted on January 06, 2014 at 13:14Hi,
I would need 3 USARTs for a project (I am using stm32f103vct6 microcontroller). One USART is already functional properly which is USART1. I am trying same with USART2. Transmit is working fine but but RXNE flag is falsely setting up here and hence its giving garbage Rx character. I tried same code using arm-none-linux-gcc compiler in which its working fine (no false RXNE flag setting), hence i thought it could be compiler related issue. I am posting my code for reference.
void USART2_Init(void)
{
GPIO_InitTypeDef GPIO_InitStructure;
USART_InitTypeDef USART_InitStructure;
//enable bus clocks
RCC_APB2PeriphClockCmd( RCC_APB2Periph_GPIOA | RCC_APB2Periph_AFIO, ENABLE);
RCC_APB1PeriphClockCmd(RCC_APB1Periph_USART2,ENABLE);
//Set USART2 Tx (PA2) as AF push-pull
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_2;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_Init(GPIOA, &GPIO_InitStructure);
//Set USART2 Rx (PA3) as input floating
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_3;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;
GPIO_Init(GPIOA, &GPIO_InitStructure);
USART_InitStructure.USART_BaudRate = 115200;
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(USART2, &USART_InitStructure);
//Enable USART2
USART_Cmd(USART2, ENABLE);
}
/* Usart functions --------------------------------- ------------------------*/
/*******************************************************************************
* Function Name : SerialPutChar
* Description : Print a character on the HyperTerminal
* Input : - c: The character to be printed
* Output : None
* Return : None
*******************************************************************************/
void SerialPutChar(u8 c)
{
USART_SendData(USART2, c);
while (USART_GetFlagStatus(USART2, USART_FLAG_TXE) == RESET);
}
int GetChar (void)
{
while (USART_GetFlagStatus(USART2, USART_FLAG_RXNE) == RESET);
return USART_ReceiveData(USART2);
}
/*******************************************************************************
* Function Name : Serial_PutString
* Description : Print a string on the HyperTerminal
* Input : - s: The string to be printed
* Output : None
* Return : None
*******************************************************************************/
void Serial_PutString(u8 *s)
{
while (*s != '\0')
{
SerialPutChar(*s);
s ++;
}
}
void main()
{
int data;
USART1_Init();
Serial_PutString(''This is test put string function on open source compiler\r\n'');
//printf(''This is containing the printf debug command\r\n'');
while(1)
{
data = GetChar();
SerialPutChar(data);
}
}
#stm32f103-usart
