如何向Arduino串行发送多个不同的浮点数或十进制值？

Question

我正在尝试将两个不同的十进制值串行发送到 Arduino。发送到 Arduino 的值由逗号 (,) 分隔：

例如1.23,4.56

我的问题是，当 Arduino 微控制器接收到这些值时，代码似乎没有输出所需的结果。

下面代码中的 Serial.println 命令都为变量 value_1 和 value_2 输出以下内容：

1.20

0.00

4.50

0.00

所以我不明白的是为什么两个变量中都有一个额外的“0.00”值。

提前致谢。

const int MaxChars = 3; // an int string contains up to 3 digits (3 s.f.) and
                        // is terminated by a 0 to indicate end of string
char strValue_1[MaxChars+1]; // must be big enough for digits and terminating null
char strValue_2[MaxChars+1]; // must be big enough for digits and terminating null
 int index_1 = 0;         // the index into the array storing the received digits
 int index_2 = 0;         // the index into the array storing the received digits
 double value_1;
 double value_2;

 void setup()
 { 
   Serial.begin(9600); // Initialize serial port to send and receive at 9600 baud
 }

 void loop()
{
 if(Serial.available())
 {
char ch = Serial.read();
if(index_1 <  MaxChars && ch >= '.' && ch <= '9')
{
  strValue_1[index_1++] = ch; // add the ASCII character to the array;

}
else if (ch == ',')
{ 
    if(index_2 <  MaxChars && ch >= '.' && ch <= '9')
    {
      strValue_2[index_2++] = ch; // add the ASCII character to the array;
    }
}
else
{
  // here when buffer full or on the first non digit
  strValue_1[index_1] = 0;        // terminate the string with a 0
  strValue_2[index_2] = 0;        // terminate the string with a 0
  value_1 = atof(strValue_1);     // use atof to convert the string to an float
  value_2 = atof(strValue_2);     // use atof to convert the string to an float
  Serial.println(value_1);  
  Serial.println(value_2);  
  index_1 = 0;
  index_2 = 0;
}
}
}

以下是@mactro 和@aksonlyaks 建议的代码的最新编辑版本，我仍然无法获得所需的输出；因此我愿意接受更多建议。

截至目前，我收到的针对以下变量的特定输入 1.23、4.56 的输出是：

str值[0]:

1.2

str值[1]:

1.2

4.5

value_1:

1.20

0.00

value_2:

1.20

4.50

提前致谢。

这是代码的最新版本：

const int MaxChars = 4; // an int string contains up to 3 digits (3 s.f.) including the '[=11=]' and
                    // is terminated by a 0 to indicate end of string

const int numberOfFields = 2;  //Amount of Data to be stored
char strValue[numberOfFields][MaxChars+1]; // must be big enough for digits and terminating null

int index_1 = 0;         // the index into the array storing the received digits

double value_1;
double value_2;

int arrayVal = 0;

void setup()
{ 
  Serial.begin(9600); // Initialize serial port to send and receive at 9600 baud
}

void loop()
{

 if(Serial.available())
{
    char ch = Serial.read();

if (ch == ',')
{ 
    arrayVal = 1;

    if(index_1 <  MaxChars-1 && ch >= '.' && ch <= '9')
    {
      strValue[arrayVal][index_1++] = ch; // add the ASCII character to the array;
    }
    if(index_1 == MaxChars - 1)
    {
      strValue[arrayVal][index_1++] = '[=11=]';
    }

 }
 else if(index_1 <  MaxChars-1 && ch >= '.' && ch <= '9')
 {
   strValue[arrayVal][index_1++] = ch; // add the ASCII character to the array;

 if(index_1 == MaxChars - 1)
 {
    strValue[arrayVal][index_1++] = '[=11=]';
 }

 }

 else
 {

  value_1 = atof(strValue[0]);     // use atof to convert the string to an float
  value_2 = atof(strValue[1]);     // use atof to convert the string to an float
  Serial.println(value_1);  
  Serial.println(value_2);  
  index_1 = 0;
  arrayVal = 0;
}
}
}

Answer 1

您永远不会向 strValue_2 添加任何内容，因为

if(index_2 <  MaxChars && ch >= '.' && ch <= '9')
{
  strValue_2[index_2++] = ch; // add the ASCII character to the array;
}

仅在ch==','时执行。当您收到逗号时，您应该设置一个标志，这将发出代码将更多字符写入 strValue_2 而不是 strValue_1。或者你可以有一个字符串数组，如 char strValues[2][MaxChars+1] 和你写入 strValues[stringNumber][index++].

的元素的更改和索引

Answer 2

我对您的代码做了一些修改，现在可以打印您想要的内容。修改后的代码如下：

const int MaxChars = 4; // an int string contains up to 3 digits (3 s.f.) including the '[=10=]' and
                    // is terminated by a 0 to indicate end of string

const int numberOfFields = 2;  //Amount of Data to be stored
char strValue[numberOfFields][MaxChars+1]; // must be big enough for digits and terminating null

int index_1 = 0;         // the index into the array storing the received digits

double value_1;
double value_2;

int arrayVal = 0;

void setup()
{ 
  Serial.begin(9600); // Initialize serial port to send and receive at 9600 baud
}

void loop()
{

    if(Serial.available())
    {
        char ch = Serial.read();

        if (ch == ',')
        { 
            arrayVal = 1;
            index_1 = 0;    // Initialise this to zero for the float value received after ','
/*
            if(index_1 <  MaxChars-1 && ch >= '.' && ch <= '9')
            {
              strValue[arrayVal][index_1++] = ch; // add the ASCII character to the array;
            }
            if(index_1 == MaxChars - 1)
            {
              strValue[arrayVal][index_1++] = '[=10=]';
            }
*/
         }
         else if( (index_1 <  MaxChars + 1) && (ch >= '.' && ch <= '9'))  // one float value size including null character is 5 (1.23 size 4)
         {
            strValue[arrayVal][index_1++] = ch; // add the ASCII character to the array;
            if(index_1 == MaxChars)             // When we have recevied the 4 character of float value add NULL character
            {
                strValue[arrayVal][index_1++] = '[=10=]';
            }
         }else
         {
            value_1 = atof(strValue[0]);     // use atof to convert the string to an float
            value_2 = atof(strValue[1]);     // use atof to convert the string to an float
            Serial.println(value_1);  
            Serial.println(value_2);  
            index_1 = 0;
            arrayVal = 0;
         }
    }
}

此外，我为您的代码做了适当的缩进。

如果有帮助请告诉我。

此致

如何向Arduino串行发送多个不同的浮点数或十进制值？

How to send multiple different floating point or decimal values serially to Arduino?

precision

serial-port

arduino

multiple-variable-return

atof