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#include "usart.h"
extern USART usart3;
// init functions
void usart_init(USART *usart, uint8_t *rx_buffer, uint16_t rx_buffersize, uint8_t *tx_buffer, uint16_t tx_buffersize)
{
// clock config
rcc_periph_clock_enable(RCC_GPIOB); // for USART3
rcc_periph_clock_enable(RCC_USART3); // for USART3
// gpio config
gpio_set_mode(GPIOB, GPIO_MODE_OUTPUT_50_MHZ, GPIO_CNF_OUTPUT_ALTFN_PUSHPULL, GPIO_USART3_TX); // TX setup
gpio_set_mode(GPIOB, GPIO_MODE_INPUT, GPIO_CNF_INPUT_FLOAT, GPIO_USART3_RX); // RX setup
// nvic config
nvic_enable_irq(NVIC_USART3_IRQ);
usart_enable_rx_interrupt(USART3);
// usart config
usart_set_baudrate(USART3, 9600);
usart_set_databits(USART3, 8);
usart_set_flow_control(USART3, USART_FLOWCONTROL_NONE);
usart_set_mode(USART3, USART_MODE_TX_RX);
usart_set_parity(USART3, USART_PARITY_NONE);
usart_set_stopbits(USART3, USART_STOPBITS_1);
usart_enable(USART3);
// fifo init
fifo_init(&usart->rx_fifo, rx_buffer, rx_buffersize);
fifo_init(&usart->tx_fifo, tx_buffer, tx_buffersize);
}
// write functions
uint16_t usart_write_bytes(USART *usart, uint8_t *data_source, uint16_t data_length){
if ((data_length + fifo_bytes_available(&usart->tx_fifo)) <= fifo_get_buffersize(&usart->tx_fifo)){
for (int i=0; i<data_length; i++){
fifo_put_byte(&usart->tx_fifo, &data_source[i]);
}
usart_enable_tx_interrupt(USART3);
return data_length;
}
else{
return 0;
}
}
uint16_t usart_write(USART *usart, char *str)
{
return usart_write_bytes(usart, (uint8_t *)str, (uint16_t)strlen(str));
}
uint16_t usart_writeln(USART *usart, char *str)
{
char buffer[(uint16_t)strlen(str)+2]; // space for str, \r and \0
strcat(buffer, str);
strcat(buffer, "\r");
return usart_write(usart, buffer);
}
// read functions
uint16_t usart_read_bytes(USART *usart, uint8_t *data_sink, uint16_t data_length)
{
if (data_length <= fifo_bytes_available(&usart->rx_fifo)){
for (int i=0; i<data_length; i++){
fifo_get_byte(&usart->rx_fifo, &data_sink[i]);
}
return data_length;
}
else{
return 0;
}
}
//uint16_t usart_read(USART *usart, char *data_sink, uint16_t data_length);
//uint16_t usart_readln(USART *usart, char *data_sink);
// usart isr
void usart3_isr(void)
{
/* Check if we were called because of RXNE. */
if (((USART_CR1(USART3) & USART_CR1_RXNEIE) != 0) &&
((USART_SR(USART3) & USART_SR_RXNE) != 0)) {
/* Retrieve the data from the peripheral. */
uint8_t data = usart_recv(USART3);
fifo_put_byte(&usart3.rx_fifo, &data);
/* Enable transmit interrupt so it sends back the data. */
//USART_CR1(USART3) |= USART_CR1_TXEIE;
}
/* Check if we were called because of TXE. */
if (((USART_CR1(USART3) & USART_CR1_TXEIE) != 0) &&
((USART_SR(USART3) & USART_SR_TXE) != 0)) {
/* Put data into the transmit register. */
if (fifo_bytes_available(&usart3.tx_fifo)){
uint8_t data;
fifo_get_byte(&usart3.tx_fifo, &data);
usart_send(USART3, data);
if(data == '\r'){
uint8_t nl = (uint8_t)'\n';
usart_write_bytes(&usart3, &nl, 1);
}
if (fifo_bytes_available(&usart3.tx_fifo)){
usart_enable_tx_interrupt(USART3);
}
else{
usart_disable_tx_interrupt(USART3);
}
}
}
}
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