我'm trying to send data to an Arduino via a serial communication. I'm使用缓冲区来存储我想发送的字节，然后使用 fwrite 命令将它们写入串口 .
Sender (Matlab)
disp(bufferSend);
fwrite(xbee,bufferSend,'uint8');
disp('sent:');
xbee.ValuesSent
display命令显示已发送 255 个字节：
2 1 0 0 0 1 1 13 17 0 30 0 12 14 0 0 0 1 0
[...] 0 0 0 [...] 0
sent:
255
Receiver (Arduino)
收到的值是正确的，直到 7-th byte . 只收到 70 bytes ;
Arduino串行监视器使用以下代码打印一个字节：
byte getData;
[...]
while(xbee.available()>0)
{
getData = xbee.read();
Serial.print("Received: ");
Serial.print(getData);
Serial.print(" Bin: ");
Serial.print(getData,BIN);
Serial.print(" Hex: ");
Serial.print(getData,HEX);
Serial.print(" cont: ");
Serial.print(cont);
Serial.println();
[...]
}
这是输出：
Matlab communication established.
Received: 2 Bin: 10 Hex: 2 cont: 2
Received: 1 Bin: 1 Hex: 1 cont: 3
Received: 0 Bin: 0 Hex: 0 cont: 4
Received: 0 Bin: 0 Hex: 0 cont: 5
Received: 0 Bin: 0 Hex: 0 cont: 6
Received: 1 Bin: 1 Hex: 1 cont: 7
Received: 1 Bin: 1 Hex: 1 cont: 8
Received: 141 Bin: 10001101 Hex: 8D cont: 9
Received: 145 Bin: 10010001 Hex: 91 cont: 10
Received: 128 Bin: 10000000 Hex: 80 cont: 11
Received: 143 Bin: 10001111 Hex: 8F cont: 12
Received: 128 Bin: 10000000 Hex: 80 cont: 13
Received: 134 Bin: 10000110 Hex: 86 cont: 14
Received: 135 Bin: 10000111 Hex: 87 cont: 15
Received: 128 Bin: 10000000 Hex: 80 cont: 16
Received: 128 Bin: 10000000 Hex: 80 cont: 17
Received: 128 Bin: 10000000 Hex: 80 cont: 18
Received: 128 Bin: 10000000 Hex: 80 cont: 19
Received: 128 Bin: 10000000 Hex: 80 cont: 20
Received: 128 Bin: 10000000 Hex: 80 cont: 21
Received: 128 Bin: 10000000 Hex: 80 cont: 22
Received: 128 Bin: 10000000 Hex: 80 cont: 23
Received: 128 Bin: 10000000 Hex: 80 cont: 24
Received: 128 Bin: 10000000 Hex: 80 cont: 25
Received: 128 Bin: 10000000 Hex: 80 cont: 26
Received: 128 Bin: 10000000 Hex: 80 cont: 27
Received: 128 Bin: 10000000 Hex: 80 cont: 28
Received: 128 Bin: 10000000 Hex: 80 cont: 29
Received: 128 Bin: 10000000 Hex: 80 cont: 30
Received: 128 Bin: 10000000 Hex: 80 cont: 31
Received: 128 Bin: 10000000 Hex: 80 cont: 32
Received: 128 Bin: 10000000 Hex: 80 cont: 33
Received: 128 Bin: 10000000 Hex: 80 cont: 34
Received: 64 Bin: 1000000 Hex: 40 cont: 35
Received: 64 Bin: 1000000 Hex: 40 cont: 36
Received: 64 Bin: 1000000 Hex: 40 cont: 37
Received: 64 Bin: 1000000 Hex: 40 cont: 38
Received: 64 Bin: 1000000 Hex: 40 cont: 39
Received: 64 Bin: 1000000 Hex: 40 cont: 40
Received: 64 Bin: 1000000 Hex: 40 cont: 41
Received: 64 Bin: 1000000 Hex: 40 cont: 42
Received: 64 Bin: 1000000 Hex: 40 cont: 43
Received: 64 Bin: 1000000 Hex: 40 cont: 44
Received: 64 Bin: 1000000 Hex: 40 cont: 45
Received: 64 Bin: 1000000 Hex: 40 cont: 46
Received: 64 Bin: 1000000 Hex: 40 cont: 47
Received: 64 Bin: 1000000 Hex: 40 cont: 48
Received: 64 Bin: 1000000 Hex: 40 cont: 49
Received: 64 Bin: 1000000 Hex: 40 cont: 50
Received: 64 Bin: 1000000 Hex: 40 cont: 51
Received: 64 Bin: 1000000 Hex: 40 cont: 52
Received: 64 Bin: 1000000 Hex: 40 cont: 53
Received: 64 Bin: 1000000 Hex: 40 cont: 54
Received: 64 Bin: 1000000 Hex: 40 cont: 55
Received: 64 Bin: 1000000 Hex: 40 cont: 56
Received: 64 Bin: 1000000 Hex: 40 cont: 57
Received: 64 Bin: 1000000 Hex: 40 cont: 58
Received: 64 Bin: 1000000 Hex: 40 cont: 59
Received: 32 Bin: 100000 Hex: 20 cont: 60
Received: 32 Bin: 100000 Hex: 20 cont: 61
Received: 32 Bin: 100000 Hex: 20 cont: 62
Received: 32 Bin: 100000 Hex: 20 cont: 63
Received: 32 Bin: 100000 Hex: 20 cont: 64
Received: 0 Bin: 0 Hex: 0 cont: 65
Received: 0 Bin: 0 Hex: 0 cont: 66
Received: 0 Bin: 0 Hex: 0 cont: 67
Received: 0 Bin: 0 Hex: 0 cont: 68
Received: 0 Bin: 0 Hex: 0 cont: 69
Received: 0 Bin: 0 Hex: 0 cont: 70
Received: 0 Bin: 0 Hex: 0 cont: 71
[...]
如果将eigth值（即13）放在缓冲区的第一个位置，Arduino会正确接收它 .
它与 fwrite 函数和缓冲区维度有关吗？这是缓冲区溢出的情况吗？
Solution
减慢波特率！在我的情况下，19200工作
2 回答
这看起来像硬件问题 . 看起来这些值的位被破坏了 .
141是13，第一位翻转
145是17，第一位翻转
128是0，第一位翻转
143向右移动30，第一位翻转
你还没有说过matlab是如何与xbee连接的 . 问题可能是不兼容的电压水平或波特率？像这样的问题会显示第一个字节的症状是正常的，然后随着通信不同步，字节变坏 . 如果这是问题，那么错误会出现一些随机性 . 对于给定的字节集，接收的值是否始终相同？
xbee模块之间的通信可能没问题，因为应该有一个校验和来确保数据包没有损坏 .
这留下了matlab和第一个xbee之间的串行通信，以及屏蔽和arduino之间的串行通信 .
您也可以尝试
Serial.readBytes()调用，看看是否有所作为 .你所经历的是一个简单的例子，太多的事情，没有足够的时间去做 . 这就是为什么最好的串行I / O例程运行一个中断的原因，它基本上强制所有程序级处理在一个字节进入接收移位寄存器（通常是UART）时停止，这样它就可以保存在在下一个字节进入之前的缓冲区 . 在没有中断例程的情况下，您无法编写代码来处理每个字节，因为如您所见，您可能会面临无法返回主要任务的风险 . 快速保存字节 . 您可能认为您没有“处理”每个字节，但print（）函数会产生巨大的开销 .
我建议重新编写你的接收例程，除了将字节添加到缓冲区，保持接收的字节数，并密切关注收到NO DATA已经过了多少时间 . 在这里你必须决定多长时间才能考虑传入的消息结束 . 然后......当消息完全存储后，您可以返回并打印出您复活的分析 . 按照这种方法，您几乎肯定能够在接近最大波特率的情况下运行！ ;-)