mongoose/examples/esp32/uart-bridge/main/uart.c

#include "main.h"

int uart_close(int no) {
  return uart_driver_delete(no);
}

int uart_open(int no, int rx, int tx, int cts, int rts, int baud) {
  uart_config_t uart_config = {
      .baud_rate = baud,
      .data_bits = UART_DATA_8_BITS,
      .parity = UART_PARITY_DISABLE,
      .stop_bits = UART_STOP_BITS_1,
      .flow_ctrl = cts > 0 && rts > 0 ? UART_HW_FLOWCTRL_CTS_RTS
                   : cts > 0          ? UART_HW_FLOWCTRL_CTS
                   : rts > 0          ? UART_HW_FLOWCTRL_RTS
                                      : UART_HW_FLOWCTRL_DISABLE,
  };
  int e1 = uart_param_config(no, &uart_config);
  int e2 = uart_set_pin(no, tx, rx, rts, cts);
  int e3 =
      uart_driver_install(no, UART_FIFO_LEN * 2, UART_FIFO_LEN * 2, 0, NULL, 0);
  MG_INFO(("%d: %d/%d/%d, %d %d %d", no, rx, tx, baud, e1, e2, e3));
  if (e1 != ESP_OK || e2 != ESP_OK || e3 != ESP_OK) return -1;
  return no;
}

void uart_init(int tx, int rx, int baud) {
  uart_open(UART_NO, rx, tx, -1, -1, baud);
}

int uart_read(void *buf, size_t len) {
  size_t x = 0;
  int no = UART_NO;
  if (uart_get_buffered_data_len(no, &x) != ESP_OK || x == 0) return 0;
  int n = uart_read_bytes(no, buf, len, 10 / portTICK_PERIOD_MS);
  MG_DEBUG(("%d bytes: [%.*s]", n, n, (char *) buf));
  return n;
}

int uart_write(const void *buf, int len) {
  int no = UART_NO;
  MG_DEBUG(("%d bytes: [%.*s]", len, len, (char *) buf));
  return uart_write_bytes(no, (const char *) buf, len);
}