如果有人发现了这一点，我们不能在一次传输中发送超过32字节的数据，我们可以拆分数据，发送少于32字节的数据，或者循环字符串并发送每个字节。

// onReceiveEvent, doesn't work
void sendMessage()
{
    Wire.write(data, LENGTH); // data length is 50 byte
                              // this however, work if LENGTH < 32
}

// onReceiveEvent, work
void sendMessage()
{
    for (int i = 0; i < LENGTH; i++)
    {
        Wire.write(data[i]);
    }
}

// reason: in file twi.c:332
/* 
 * Function twi_transmit
 * Desc     fills slave tx buffer with data
 *          must be called in slave tx event callback
 * Input    data: pointer to byte array
 *          length: number of bytes in array
 * Output   1 length too long for buffer
 *          2 not slave transmitter
 *          0 ok
 */
uint8_t twi_transmit(const uint8_t* data, uint8_t length)
{
  uint8_t i;

  // ensure data will fit into buffer
  if(TWI_BUFFER_LENGTH < (twi_txBufferLength+length)){
    return 1;
  }

  ...

  twi_txBufferLength += length;
  
  return 0;
}

我仍然可以使用相同的python脚本，只是arduino不能在一次传输中发送超过32个字节。