2008-10-15 04:41 PM
UART problem
2011-05-17 03:47 AM
Hello,
I am new with the STM32 programming and I have some problems using the UART. I tried some examples and I can´t see any output on Windows Hyper Terminal, I really don´t know what is the problem. I am using the Raisonance REva starter kit and this is the source I use: int main(void) { RCC_Configuration(); NVIC_Configuration(); GPIO_Configuration(); UART_Configuration(); USART_Cmd(USART1, ENABLE); printf(''USART Printf Example: retarget the C library printf function to the USART''); while (1) { } } void RCC_Configuration(void) { RCC_DeInit(); RCC_HSEConfig(RCC_HSE_ON); HSEStartUpStatus = RCC_WaitForHSEStartUp(); if(HSEStartUpStatus == SUCCESS) { FLASH_PrefetchBufferCmd(FLASH_PrefetchBuffer_Enable); FLASH_SetLatency(FLASH_Latency_2); RCC_HCLKConfig(RCC_SYSCLK_Div1); RCC_PCLK2Config(RCC_HCLK_Div1); RCC_PCLK1Config(RCC_HCLK_Div2); /* PLLCLK = 8MHz * 9 = 72 MHz */ RCC_PLLConfig(RCC_PLLSource_HSE_Div1, RCC_PLLMul_9); RCC_PLLCmd(ENABLE); while(RCC_GetFlagStatus(RCC_FLAG_PLLRDY) == RESET) { } RCC_SYSCLKConfig(RCC_SYSCLKSource_PLLCLK); while(RCC_GetSYSCLKSource() != 0x08) { } } RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA | RCC_APB2Periph_AFIO | RCC_APB2Periph_USART1, ENABLE); } void GPIO_Configuration(void) { /* 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); /* Configure 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); } void UART_Configuration(void) { /* USARTx configured as follow: - BaudRate = 9600 baud - Word Length = 8 Bits - One Stop Bit - No 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); } /******************************************************************************* * Function Name : PUTCHAR_PROTOTYPE * Description : Retargets the C library printf function to the USART. * Input : None * Output : None * Return : None *******************************************************************************/ PUTCHAR_PROTOTYPE { /* Write a character to the USART */ USART_SendData(USART1, (u8) ch); /* Loop until the end of transmission */ while(USART_GetFlagStatus(USART1, USART_FLAG_TXE) == RESET) { } return ch; } [ This message was edited by: marcl on 08-10-2008 15:34 ]2011-05-17 03:47 AM
try this:
PUTCHAR_PROTOTYPE { while(!USART_GetFlagStatus(USART1, USART_FLAG_TXE)) { } USART_SendData(USART1, (u8) ch); }2011-05-17 03:47 AM