Question

我收到的信息包如0xFA5D0D01。现在我想像

那样进行分类

FA是Header1 5D是Header2 0D是长度和 01是校验和。 const int data_availabe = Serial.available（）;

我可以写入串口但不能像它一样如果我收到FA则打印收到Header1

const int data_availabe = Serial.available();
if (data_availabe <= 0) 
{
    return;
}
const int c = Serial.read();

Serial.print("Receive Status: ");
Serial.println(STATE_NAME[receiveState]);
Serial.print(c, HEX);
Serial.print(" ");
if (isprint(c))          //isprint checks whether it is printable character or not (e.g non printable char = \t)
{
  Serial.write(c);
} 
Serial.println();   
Serial.println(receiveState);   

switch (receiveState)
{
case WAITING_FOR_HEADER1:
    if (c == HEADER1)
    {
        receiveState = WAITING_FOR_HEADER2;

    }
    break;

case WAITING_FOR_HEADER2:
    if (c == HEADER2)
    {
        receiveState = WAITING_FOR_LENGTH;
    }
    break;
}

当我们获取被删除的数据时，其中receiveState是枚举更改。

Answer 1

我认为Arduino正在从USB接收数据。

if (data available <= 0)在做什么？如果您希望在可用的情况下从串口读取数据，则最好在if (Serial.avalaible() > 1)内Serial.read()然后{}进行操作。

如果您初始化const，则无法随时间更改其值...

什么是readString以及它是如何初始化的？

您是否尝试Serial.print(c)看看里面有什么？

如果你能给我们更多关于这段代码运行的原因和时间的背景，我们会更容易。

修改：

#define HEADER_1 0xFA // here you define your headers, etc. You can also use variables. uint8_t readByte[4]; // your packet is 4 bytes long. each byte is stored in this array. void setup() { Serial.begin(9600); } void loop() { while (Serial.avalaible() > 1) { // when there is data avalaible on the serial port readByte[0] = Serial.read(); // we store the first incomming byte. delay(10); if (readByte[0] == HEADER_1) { // and check if that byte is equal to HEADER_1 for (uint8_t i = 1 ; i < 4 ; i++) { // if so we store the 3 last bytes into the array readByte[i] = Serial.read(); delay(10); } } } //then you can do what you want with readByte[]... i.e. check if readByte[1] is equal to HEADER_2 and so on :) }

解析传入的数据包

1 个答案: