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#include "project.h"
#define BUFFER_SIZE 256
#define USART1_TX GPIO_USART1_TX
#define USART1_TX_PORT GPIOA
#define USART1_RX GPIO_USART1_RX
#define USART1_RX_PORT GPIOA
ring_t rx1_ring;
static uint8_t rx1_ring_buf[BUFFER_SIZE];
ring_t tx1_ring;
static uint8_t tx1_ring_buf[BUFFER_SIZE];
void
usart1_isr (void)
{
uint8_t data;
/* Check if we were called because of RXNE. */
if (((USART_CR1 (USART1) & USART_CR1_RXNEIE) != 0) &&
((USART_SR (USART1) & USART_SR_RXNE) != 0))
{
data = usart_recv (USART1);
ring_write_byte (&rx1_ring, data);
}
/* Check if we were called because of TXE. */
if (((USART_CR1 (USART1) & USART_CR1_TXEIE) != 0) &&
((USART_SR (USART1) & USART_SR_TXE) != 0))
{
if (ring_read_byte (&tx1_ring, &data))
{
/*No more data, Disable the TXE interrupt, it's no longer needed. */
usart_disable_tx_interrupt (USART1);
}
else
{
usart_send_blocking (USART1, data);
}
}
}
void
usart1_queue (uint8_t d)
{
ring_write_byte (&tx1_ring, d);
usart_enable_tx_interrupt (USART1);
}
void
usart1_drain (void)
{
while (!ring_empty (&tx1_ring));
}
int
usart1_write (char *ptr, int len, int blocking)
{
int ret;
ret = ring_write (&tx1_ring, (uint8_t *) ptr, len, blocking);
usart_enable_tx_interrupt (USART1);
return ret;
}
void
usart_init (void)
{
ring_init (&rx1_ring, rx1_ring_buf, sizeof (rx1_ring_buf));
ring_init (&tx1_ring, tx1_ring_buf, sizeof (tx1_ring_buf));
nvic_enable_irq (NVIC_USART1_IRQ);
MAP_AF (USART1_TX);
MAP_AF_PU (USART1_RX);
usart_set_baudrate (USART1, 38400);
usart_set_databits (USART1, 8);
usart_set_stopbits (USART1, USART_STOPBITS_1);
usart_set_parity (USART1, USART_PARITY_NONE);
usart_set_flow_control (USART1, USART_FLOWCONTROL_NONE);
usart_set_mode (USART1, USART_MODE_TX_RX);
USART_CR1 (USART1) |= USART_CR1_RXNEIE;
usart_enable (USART1);
}
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