Passing a string with multiple variables to anrduino using serial port - arduino

Question

Im trying to pass a string generated using processing to the Arduino serial port but it doesn't seem to work.
Arduino Code:
String readString; //main captured String
String MotorChoice;
String AngleRange;
String FrequencyIN;
int ind1;
int ind2;
int ind3;
int MC;
int AR;
float FIN;
void setup() {
Serial.begin(9600);
Serial.println("Input command in the form of Motor Choice,Angle Range,Frequency*");
}
void loop()
{
if (Serial.available()) {
char c = Serial.read();
if (c == '*') {
Serial.println();
Serial.print("captured String is : ");
Serial.println(readString);
ind1 = readString.indexOf(','); //finds location of first ,
MotorChoice = readString.substring(0, ind1); //captures first data String
ind2 = readString.indexOf(',', ind1+1 ); //finds location of second ,
AngleRange = readString.substring(ind1+1, ind2); //captures second data String
ind3 = readString.indexOf(',', ind2+1 );
FrequencyIN = readString.substring(ind2+1);
//convert sring to int
MC = MotorChoice.toInt();
AR = AngleRange.toInt();
FIN = FrequencyIN.toFloat();
Serial.print("Motor Selected = ");
Serial.println(MC);
Serial.print("Angle Range = ");
Serial.println(AR);
Serial.print("Frequency Required = ");
Serial.println(FIN);
Serial.println();
Serial.println();
readString=""; //clears variable for new input
MotorChoice="";
AngleRange="";
FrequencyIN="";
}
else
{
readString += c; //makes the string readString
}
}
}
Processing Code:
import processing.serial.*;
Serial myPort;
println(Serial.list());
myPort = new Serial(this, Serial.list()[0], 9600);
int M =1;
int A =90;
float F =2.5;
String sM = str(M);
String sA = str(A);
String sF = str(F);
String sb;
String s1;
sb = sM +","+ sA+"," + sF+"*";
s1 = sb;
println(s1);
myPort.write(s1);
The above Arduino code has previously been tried out where an input was fed using the serial monitor in the format of motor,angle,frequency*
Any help would greatly be appreciated.

Answer 1

If I am interpreting your code correctly you are using the * character as a way of signifying the end of the list. But in your Arduino code you are checking for the * then you are printing the output string. Thus, the rest of your array is long gone by that point. Also, you set a variable at the beginning called readString but you never set it to anything. That's why you you're not seeing any output.
First I would start by changing your variable name from readString to something else (for the sake of clarity) then use Serial.readString() to get that string from the serial port. Then check the last character of that string for the * character.
if (Serial.available()) {
String str = Serial.readString(); // get string
char c = str[strlen(str)-1]; // find *
if (c == '*') {
Serial.print("Output: ");
Serial.println(str);
//The rest of your code
}