Arduino 串口解析

Question

我正在制作一个 Arduino 草图，我正在尝试使用串行更改一个变量。我正在使用我在 arduino.cc 上找到的一些示例代码开始。我正在尝试使用“if 语句”修改代码以使用integerFromPC 更新变量timevar；我遇到的问题是，如果我输入一个高于 4 位的数字，例如 99999，它会打印出错误的数据并且变量 timevar 没有正确更新？我不知道该怎么办？

unsigned long timevar = 1000000;
const byte numChars = 32;
char receivedChars[numChars];
char tempChars[numChars];        // temporary array for use when parsing

// variables to hold the parsed data
char messageFromPC[numChars] = {0};
int integerFromPC = 0;
int ifpc = 0;
float floatFromPC = 0.0;


boolean newData = false;

//============

void setup() {
    Serial.begin(9600);
    Serial.println("This demo expects 3 pieces of data - text, an integer and a floating point value");
    Serial.println("Enter data in this style <HelloWorld, 12, 24.7>  ");
    Serial.println();
}

//============

void loop() {
    recvWithStartEndMarkers();
    if (newData == true) {
        strcpy(tempChars, receivedChars);
            // this temporary copy is necessary to protect the original data
            // because strtok() used in parseData() replaces the commas with \0
        parseData();
        showParsedData();
        newData = false;
    }
}

//============

void recvWithStartEndMarkers() {
    static boolean recvInProgress = false;
    static byte ndx = 0;
    char startMarker = '<';
    char endMarker = '>';
    char rc;

    while (Serial.available() > 0 && newData == false) {
        rc = Serial.read();

        if (recvInProgress == true) {
            if (rc != endMarker) {
                receivedChars[ndx] = rc;
                ndx++;
                if (ndx >= numChars) {
                    ndx = numChars - 1;
                }
            }
            else {
                receivedChars[ndx] = '\0'; // terminate the string
                recvInProgress = false;
                ndx = 0;
                newData = true;
            }
        }

        else if (rc == startMarker) {
            recvInProgress = true;
        }
    }
}

//============

void parseData() {      // split the data into its parts

    char * strtokIndx; // this is used by strtok() as an index

    strtokIndx = strtok(tempChars,",");      // get the first part - the string
    strcpy(messageFromPC, strtokIndx); // copy it to messageFromPC

    strtokIndx = strtok(NULL, ","); // this continues where the previous call left off
    integerFromPC = atoi(strtokIndx);


    strtokIndx = strtok(NULL, ",");
    floatFromPC = atof(strtokIndx);     // convert this part to a float

}

//============

void showParsedData() {
    if (strcmp(messageFromPC, "set time") == 0) 
        timevar = integerFromPC;
    Serial.print("Time Set To ");
    Serial.println(integerFromPC);
    Serial.println(timevar);

  }
    //do other stuff

Answer 1

您声明int integerFromPC。 Arduino 上的int 是 16 位。 99999 不适合 16 位，因此将显示 mod 2^16 为 34463。请使用 long 代替 timeVar，最多 +/- 2^31 也可以。