Posted on May 09, 2017 at 13:29Hi Edison,
I've tried getting data from the UART both with and without the 5V line connected but I'm not having any joy. I've connected my TTL-232R cable to my STM32F3DISCOVERY like so:
TTL-232R wire STM32F3DISCOVERY pin
5V 5V
TX PA9 (USART1_TX)
RX PA10 (USART1_RX)
GND GND
I've written the following code which I think is fine:
int main(){
...
USART1_Init();
...
while(1){
...
sendData('Testing');
...
}
}
void USART1_Init(void)
{
/* USART configuration structure for USART1 */
USART_InitTypeDef usart1_init_struct;
/* Bit configuration structure for GPIOA */
GPIO_InitTypeDef gpioa_init_struct;
/* Enable clock for USART1, AFIO and GPIOA */
RCC_APB2PeriphClockCmd(RCC_APB2Periph_USART1 | RCC_AHBPeriph_GPIOA, ENABLE);
/* GPIOA PIN9 alternative function Tx */
gpioa_init_struct.GPIO_Pin = GPIO_Pin_9;
gpioa_init_struct.GPIO_Speed = GPIO_Speed_50MHz;
gpioa_init_struct.GPIO_Mode = GPIO_Mode_AF;
GPIO_Init(GPIOA, &gpioa_init_struct);
/* GPIOA PIN10 alternative function Rx */
gpioa_init_struct.GPIO_Pin = GPIO_Pin_10;
gpioa_init_struct.GPIO_Speed = GPIO_Speed_50MHz;
gpioa_init_struct.GPIO_Mode = GPIO_Mode_IN;
GPIO_Init(GPIOA, &gpioa_init_struct);
/* Enable USART1 */
USART_Cmd(USART1, ENABLE);
/* Baud rate 9600, 8-bit data, One stop bit
* No parity, Do both Rx and Tx, No HW flow control
*/
usart1_init_struct.USART_BaudRate = 115200;
usart1_init_struct.USART_WordLength = USART_WordLength_8b;
usart1_init_struct.USART_StopBits = USART_StopBits_1;
usart1_init_struct.USART_Parity = USART_Parity_No ;
usart1_init_struct.USART_Mode = USART_Mode_Rx | USART_Mode_Tx;
usart1_init_struct.USART_HardwareFlowControl = USART_HardwareFlowControl_None;
/* Configure USART1 */
USART_Init(USART1, &usart1_init_struct);
/* Enable RXNE interrupt */
USART_ITConfig(USART1, USART_IT_RXNE, ENABLE);
/* Enable USART1 global interrupt */
NVIC_EnableIRQ(USART1_IRQn);
}
void sendData(const char *str){
while(*str){
// USART_FLAG_TXE goes HIGH when data is sent
while(USART_GetFlagStatus(USART1,USART_FLAG_TXE) == RESET);
USART_SendData(USART1, *str++);
}
}
Does this all look ok to you? Also, I assume it is ok to connect wires to the underside of the STM32F3DISCOVERY board, i.e. from the 2.54mm pitch pins?
Tony
