Trouble converting Serial.readString() to Integer

Projects Programming
1

In Processing, I'm trying to use an incoming string value using Serial.readString(), from a slide pot. Checking the value with 'print' works just fine, however whenever I try to convert it, no luck. Any suggestions? The basic code is pretty straightforward:

import processing.serial.*;

Serial myPort;
String val;
Integer valInt;

void setup() {
String portName = Serial.list()[0];
myPort = new Serial(this, portName, 9600);
}

void draw()
{
while(myPort.available() > 0){
val = myPort.readString();
println(val);

valInt = int(val); //<--- here's the problem, doesn't covert to integer
}
}

2 
valInt = int(val); //<--- here's the problem, doesn't covert to integer

What do you think the int() "function" is doing? It does NOT convert a string to an int.

Integer.parseInt(string) does.

3

Thanks PaulS,
After changing the code per your suggestion to:

valInt = Integer.parseInt(val);
println(valInt);

I get the error message:

NumberFormatExcpetion: For input string: "2ÿ"

any ideas? Sorry if this is basic, I'm just starting out! Any advice much appreciated.

4

any ideas?

Yes. Don't call the function with strings that are not representations of numeric values.

Serial input does not belong in draw(). Use the serialEvent() method. Use Serial::bufferUntil() to define when serialEvent() will be called.

After getting the string, using readStringUntil(), use String::trim() to make sure that there is no garbage in the string.

5

Have a look at Serial Input Basics - simple reliable non-blocking ways to receive data. There is also a parse example.

...R

6

Robin2:
Have a look at Serial Input Basics - simple reliable non-blocking ways to receive data. There is also a parse example.

...R

Not written for Processing, though...

7

PaulS:
Use the serialEvent() method

awesome, this worked a charm, thanks!

8

Robin2:
Have a look at Serial Input Basics - simple reliable non-blocking ways to receive data. There is also a parse example.

...R

Thanks Robin2, great material for someone starting out!

9

PaulS:
Not written for Processing, though...

Shoot. I was sure this was the Arduino Forum. Apologies ....

...R