Posted on February 27, 2013 at 16:49
Or with interrupts, something like this
// STM32W108 UART1 IRQ TX/RX Loop (PB.1 Tx, PB.2 Rx) sourcer32@gmail.com
#include ''stm32w108xx.h''
volatile char StringLoop[] = ''The quick brown fox jumps over the lazy dog
'';
/**************************************************************************************/
void SC1_IRQHandler(void)
{
static int tx_index = 0;
static int rx_index = 0;
if (UART_GetITStatus(SC1_IT, UART_IT_TXE) != RESET)
{
/* Write one byte to the transmit data register */
UART_SendData(SC1_UART, StringLoop[tx_index++]);
if (tx_index >= (sizeof(StringLoop) - 1))
tx_index = 0;
/* Clear the UART_IT_TXE pending interrupt, probably overkill */
UART_ClearITPendingBit(SC1_IT, UART_IT_TXE);
}
if (UART_GetITStatus(SC1_IT, UART_IT_RXNE) != RESET) // Received characters modify string
{
/* Read one byte from the receive data register */
StringLoop[rx_index++] = UART_ReceiveData(SC1_UART);
if (rx_index >= (sizeof(StringLoop) - 1))
rx_index = 0;
/* Clear the UART_IT_RXNE pending interrupt, probably overkill */
UART_ClearITPendingBit(SC1_IT, UART_IT_RXNE);
}
}
/**************************************************************************************/
void NVIC_Config(void)
{
NVIC_InitTypeDef NVIC_InitStructure;
/* Enable the SC1 Interrupt */
NVIC_InitStructure.NVIC_IRQChannel = SC1_IRQn;
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0x00;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0x00;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStructure);
}
/**************************************************************************************/
int main(void)
{
UART_InitTypeDef UART_InitStructure;
GPIO_InitTypeDef GPIO_InitStructure;
NVIC_Config();
/* Disable the serial controller interface */
UART_Cmd(SC1_UART, DISABLE);
/* Configure (PB1) UART Tx as alternate function push-pull */
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_1;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
GPIO_Init(GPIOB, &GPIO_InitStructure);
/* Set pull-up on UART Tx pin */
GPIO_SetBits(GPIOB, GPIO_Pin_1);
/* Configure (PB2) UART Rx as input with pull-up */
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_2;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN;
GPIO_Init(GPIOB, &GPIO_InitStructure);
/* Set pull-up on UART Rx pin */
GPIO_SetBits(GPIOB, GPIO_Pin_2);
/* UARTx configured as follow:
- BaudRate = 115200 baud
- Word Length = 8 Bits
- One Stop Bit
- No parity
- Hardware flow control disabled (RTS and CTS signals)
*/
UART_InitStructure.UART_BaudRate = 115200;
UART_InitStructure.UART_WordLength = UART_WordLength_8b;
UART_InitStructure.UART_StopBits = UART_StopBits_1;
UART_InitStructure.UART_Parity = UART_Parity_No;
UART_InitStructure.UART_HardwareFlowControl = UART_HardwareFlowControl_Disable;
/* UART configuration: Set up the parameters specific for the UART operating mode */
UART_Init(SC1_UART, UART_InitStruct);
/* Enable the UART peripheral */
UART_Cmd(SC1_UART, ENABLE);
/* Enable the SC1_IT Transmit interrupt: this interrupt is generated when the
UART transmit data register is empty */
UART_TriggerEventConfig(SC1_IT, UART_IT_TXE, SC_TriggerEvent_Level);
UART_ITConfig(SC1_IT, UART_IT_TXE, ENABLE);
/* Enable the SC1_UART Receive interrupt: this interrupt is generated when the
SC1_UART receive data register is not empty */
UART_ITConfig(SC1_IT, UART_IT_RXNE, ENABLE);
while(1);
}
/**************************************************************************************/
