Arduino:String to int得到奇怪的值

Question

我想将转换String到int,所有我能找到的是,您必须将字符串转换为字符数组,然后施放此数组的int,但我的代码产生奇怪的价值观和我想不通的问题是什么.

void ledDimm(String command)
{
    // Get the Value xx from string LEDDimm=xx
    String substring = command.substring(8, command.length());

    Serial.println("SubString:");
    Serial.println(substring);
    Serial.println("SubString Length:");
    Serial.println(substring.length());

    // Create a Char Array to Store the Substring for conversion
    char valueArray[substring.length() + 1];

    Serial.println("sizeof ValueArray");
    Serial.println(sizeof(valueArray));

    // Copy the substring into the array
    substring.toCharArray(valueArray, sizeof(valueArray));

    Serial.println("valueArray:");
    Serial.println(valueArray);

    // Convert char array to an int value
    int value = int(valueArray);

    Serial.println("Integer Value:");
    Serial.println(value);

    // Write the Value to the LEDPin
    analogWrite(LEDPin, value);
}

串行输出如下所示:

Received packet of size 11
From 192.168.1.4, port 58615
Contents:
LEDDimm=100
SubString:
100
SubString Length:
3
sizeof ValueArray
4
valueArray:
100
Integer Value:
2225

我希望得到一个值为100的int,但实际的int是2225 ?! 我在这做错了什么？

Answer 1

toInt()String类中甚至还有一个(未记录的)方法:

int myInt = myString.toInt();

Answer 2

您需要使用函数int value = atoi(valueArray);where where valueArraynull终止字符串.