ESP32 arduino 串口同时收发的问题

[lwshowl]

我用ESP NOW 开发一个无线串口穿透程序，将收到的ESP_NOW报文发送到串口，同时将串口收到的消息通过ESP NOW 发出。希望能实现串口的串流
使用ARDUINO IDE 进行的开发。
但是串口串流中间总是会中断，在 ESP NOW onRecive 里面将数据写到 TX fifo 中，在loop 中将rx 的数据通过ESP NOW 转发出去
串口转发的速率为600bit/s ，串口接收的速率也为600bit/s，理论上串口波特率已经远低于 ESP NOW onRecive 中填充 TX fifo 的速率了，应该不会停止
我发现串口的 TX RX fifo 是通过同一个 MUTEX 管理的，不知道这个MUTEX 会不会影响同一个串口的 收和发行为。

下面是代码 ┭┮﹏┭┮

Code: Select all

#include <Arduino.h>
#include <WiFi.h>
#include <esp_now.h>
#include <esp_wifi.h>

//#define DEBUG
#define RX_BOARD
//#define BLINK_ON_RECV
#define WIFI_CHANNEL 1
#define BAUD_RATE 600
#define BUFFER_SIZE 250 // max of 250 bytes


#define mSerial Serial
// TX 44:17:93:F9:52:34
// RX 44:17:93:F9:2E:C4
#ifdef RX_BOARD
const uint8_t broadcastAddress[] = {0x44, 0x17, 0x93, 0xF9, 0x52, 0x34};
#else
const uint8_t broadcastAddress[] = {0x44, 0x17, 0x93, 0xF9, 0x2E, 0xC4};
#endif
const uint32_t timeout_micros = (int)(1.0 / BAUD_RATE * 1E6);

uint8_t buf_recv[BUFFER_SIZE];
uint8_t buf_send[BUFFER_SIZE];
uint8_t buf_size = 0;

void OnDataRecv(const uint8_t *mac, const uint8_t *incomingData, int len)
{
#ifdef BLINK_ON_RECV
  digitalWrite(LED_BUILTIN, HIGH);
#endif
  //memcpy(&buf_recv, incomingData, len);
  mSerial.write(incomingData, len);
#ifdef BLINK_ON_RECV
  digitalWrite(LED_BUILTIN, LOW);
#endif
#ifdef DEBUG
  mSerial.print("\n Bytes received: ");
  mSerial.println(len);
#endif
}

void setup()
{
  //设置led 指示灯
  pinMode(LED_BUILTIN, OUTPUT);

  //设置波特率
  mSerial.begin(BAUD_RATE);
  mSerial.setRxBufferSize(50000);
  Serial.begin(BAUD_RATE);
  pinMode(16, INPUT_PULLUP);
  pinMode(17, OUTPUT);
  WiFi.mode(WIFI_STA);

#ifdef DEBUG
  mSerial.println();
  mSerial.println(WiFi.macAddress());
#endif
  // ESP_NOW 初始化
  if (esp_wifi_set_channel(WIFI_CHANNEL, WIFI_SECOND_CHAN_NONE) != ESP_OK)
  {
    mSerial.println("Error changing wifi channel");
    return;
  }

  if (esp_now_init() != ESP_OK)
  {
    mSerial.println("Error initializing ESP_NOW");
    return;
  }

  //添加peer
  esp_now_peer_info_t peerInfo;
  memcpy(peerInfo.peer_addr, broadcastAddress, 6);
  peerInfo.channel = WIFI_CHANNEL;
  peerInfo.encrypt = false;

  if (esp_now_add_peer(&peerInfo) != ESP_OK)
  {
    mSerial.println("failed to add peer");
  }

  esp_now_register_recv_cb(OnDataRecv);
}

uint64_t start;

void loop()
{
  // put your main code here, to run repeatedly:

  // read up to BUFFER_SIZE from mSerial port
  if (mSerial.available())
  {
    start = micros();
    while (mSerial.available() && buf_size < BUFFER_SIZE)
    {
      buf_send[buf_size] = mSerial.read();
      buf_size++;

      if (micros() - start > timeout_micros)
        goto WRITE;
    }
  }
  // send buffer contents when full or timeout has elapsed
  if (buf_size > 0)
  {
  WRITE:
#ifdef BLINK_ON_SEND
    digitalWrite(LED_BUILTIN, HIGH);
#endif
    // #ifdef RX_BOARD
    //     Serial.write(buf_send, buf_size);
    // #endif
    esp_now_send(broadcastAddress, (uint8_t *)&buf_send, buf_size);
    buf_size = 0;
#ifdef DEBUG
    if (result == ESP_OK)
    {
      mSerial.println("Sent!");
    }
    else
    {
      mSerial.println("Send error");
    }
#endif
#ifdef BLINK_ON_SEND
    digitalWrite(LED_BUILTIN, LOW);
#endif
  }
}

[lwshowl]

请问 arduino 里面的serial 有tx 和 rx buffer吗，读写的字节好像都是同步写入fifo.rw_bytes里面了