Posted on August 27, 2016 at 23:19I am developing a project on STM32F401RE-Nucleo which is about UART Communication.
In order to know how UART works out, I have implemented my first project.
I have connected D0 to D1 (USART2 RX to TX ) , so that I want to receive what I just sent.
Here is my configuration:
void uart_init() {
USART_InitTypeDef usart2_init_struct;
GPIO_InitTypeDef gpioa_init_struct;
RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOA, ENABLE);
RCC_APB1PeriphClockCmd(RCC_APB1Periph_USART2, ENABLE);
GPIO_PinAFConfig(GPIOA, GPIO_PinSource2, GPIO_AF_USART2);
GPIO_PinAFConfig(GPIOA, GPIO_PinSource3, GPIO_AF_USART2);
gpioa_init_struct.GPIO_Pin = GPIO_Pin_2 | GPIO_Pin_3;
gpioa_init_struct.GPIO_Speed = GPIO_Speed_2MHz;
gpioa_init_struct.GPIO_Mode = GPIO_Mode_AF;
gpioa_init_struct.GPIO_OType = GPIO_OType_PP;
gpioa_init_struct.GPIO_PuPd = GPIO_PuPd_UP;
GPIO_Init(GPIOA, &gpioa_init_struct);
usart2_init_struct.USART_BaudRate = 9600;
usart2_init_struct.USART_WordLength = USART_WordLength_8b;
usart2_init_struct.USART_StopBits = USART_StopBits_1;
usart2_init_struct.USART_Parity = USART_Parity_No;
usart2_init_struct.USART_Mode = USART_Mode_Rx | USART_Mode_Tx;
usart2_init_struct.USART_HardwareFlowControl =
USART_HardwareFlowControl_None;
USART_Init(USART2, &usart2_init_struct);
USART_Cmd(USART2, ENABLE);
USART_ITConfig(USART2, USART_IT_RXNE, ENABLE);
NVIC_InitTypeDef NVIC_InitStructure;
/* Enable the USARTx Interrupt */
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);
NVIC_EnableIRQ(USART2_IRQn);
}
and my main func:
int main(void) {
uart_init();
while (USART_GetFlagStatus(USART2, USART_FLAG_TXE) != RESET) {
USART_SendData(USART2, (uint16_t) 0x00ff);
}
while (1)
;
}
USART_SendData gets called.
I have also set an USART2_IRQHandler() which however never gets triggered.
That is my problem.
My question is whether it is a software problem or not.
I dont believe it is a hardware problem, because it is just a connection between D0 and D1 ( RX <-> TX )
