I checked the teacher gave the courseware as well as the relevant code on the net is TX pins should be configured to check push-pull output, then the RX to be floated input pin, but the teacher gave us a GPIO header file does not define GPIO_Mode_AF_PP and GPIO_Mode_IN_FLOATING and then, the book to the code I would more look not to understand, is as follows: (PA9 TX, PA10 RX)
GPIO_InitTypeDef GPIO_InitStructure;
GPIO_InitStructure. GPIO_Pin=GPIO_Pin_9;
GPIO_InitStructure. GPIO_Mode=GPIO_Mode_AF;
GPIO_InitStructure. GPIO_OType=GPIO_OType_PP;
GPIO_InitStructure. GPIO_Speed=GPIO_Speed_40MHz;
GPIO_Init (GPIOA, & amp; GPIO_InitStructure);
GPIO_PinAFConfig (GPIOA, GPIO_PinSource9 GPIO_AF_USART1);
GPIO_InitStructure. GPIO_Pin=GPIO_Pin_10;
GPIO_InitStructure. GPIO_Mode=GPIO_Mode_AF;
GPIO_InitStructure. GPIO_PuPd=GPIO_PuPd_NOPULL;
GPIO_Init (GPIOA, & amp; GPIO_InitStructure);
GPIO_PinAFConfig (GPIOA, GPIO_PinSource10 GPIO_AF_USART1);
After that, I use this configuration and use USART_SendData posted a 100, a serial port assistant display as follows, and no matter what will be sent in the start and end with a FE

But the GPIO_PinAFConfig (GPIOA, GPIO_PinSource9 GPIO_AF_USART1); After remove this saying, only display 00 serial assistants, and no matter whether I send data as long as according to the board reset button will appear 00, and only after remove the GPIO_PinAFConfig this, turn the USB serial port on the RXD, TXD corresponding LED light is on,

CodePudding user response:

1, GPIO_InitStructure. GPIO_PuPd=GPIO_PuPd_NOPULL; This is empty, this code is not the same, should be a different set of chip and the reasons of different repository,
=0 2100 x64, 60, is also not show you may baud rate is wrong, also want to check digits and check, there is no specific code I don't know.
3, 00 after reset is normal, is commonly caused by hardware circuit, temporarily forget,

CodePudding user response:

reference 1st floor forget345 response:

1, GPIO_InitStructure. GPIO_PuPd=GPIO_PuPd_NOPULL; This is empty, this code is not the same, should be a different set of chip and the reasons of different repository,
=0 2100 x64, 60, is also not show you may baud rate is wrong, also want to check digits and check, there is no specific code I don't know.
3, 00 after reset is normal, is commonly caused by hardware circuit, temporarily forget,

Floating empty that I know, but check the push-pull I feel is not like our teaching materials in such a configuration,,,
Then, the USART configuration code is as follows:
USART_InitTypeDef USART_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_HardwareFlowControl=USART_HardwareFlowControl_None;
USART_InitStructure. USART_Mode=USART_Mode_Rx | USART_Mode_Tx;
USART_Init (USART1, & amp; USART_InitStructure);
USART_Cmd (USART1, ENABLE);
USART_SENDBYTE (USART1, 100);
To send data function definition code is as follows:
Void USART_SENDBYTE (USART_TypeDef * pUSARTX, uint8_t data)
{USART_SendData (USART1, data);
While (USART_GetFlagStatus (USART1, USART_FLAG_TXE)==RESET);
}
Baud rate which I have set up is the same as the serial assistants, feel very strange

CodePudding user response:

GPIO_OType_PP is push-pull, see the PP will probably know, how much you can see the value is GPIO_OType_PP do manual and see if it is the value of the push-pull
Code looks fine, in addition to * pUSARTX useless, have the oscilloscope or logical analysis directly on MCU PA9 see, turn USB series chip is broken it is also possible,

CodePudding user response:

Function IO reuse ah, must be set GPIO_PinAFConfig, that every single chip is different, even if the same model of different packaging is different, completely depends on the specification,