Hi there, I am controlling two motors by sending data over from pd over the serial port to arduino and then out through 2 h-bridge chips and into the motors.

all works fine except that I am not getting the data to split to motor a and motor b correctly on the arduino side,

I am sending messages out of pd as integers with "a" or "b" attached to them message boxes look like [a$1

[comport]

does anyone know a good solution to get the arduno to split these streams in order to control the motors separately?

thanks in advance!

here is my arduino code, if that helps

int enablePin = 11;
int in1Pin = 10;
int in2Pin = 9;
int enablePin2 = 6;
int in1bPin = 5;
int in2bPin = 3;
int motorpins[] = {3, 5, 6, 9, 10, 11};

void setup()
{
pinMode(in1Pin, OUTPUT);
pinMode(in2Pin, OUTPUT);
pinMode(enablePin, OUTPUT);
pinMode(in1bPin, OUTPUT);
pinMode(in2bPin, OUTPUT);
pinMode(enablePin2, OUTPUT);

Serial.begin(9600);
}
void loop()
{
   if (Serial.available() >=4)  {
    char c = Serial.read();  //gets one byte from serial buffer
    int speed = Serial.read();
    if (c == 'a') {
analogWrite(enablePin, speed);
analogWrite(in1Pin, ! speed);
analogWrite(in2Pin, speed);
    }
    else if (c == 'b') {
analogWrite(enablePin2, speed);
analogWrite(in1bPin, ! speed);
analogWrite(in2bPin, speed);
}
}
}```

and sorry the pd patch didn't format right in the stick drawing above, its just showing integer going into comport with an a or b attached to the front of it.

hey, in case anyone is curious, this is the code that worked for me..I ended up splitting the stream of incoming numbers on the arduino side of the code and just using pd as an interface from which to control the motors, so nothing special in the pd code. but maybe this arduino code could help someone:

enablePin = 11;
int in1Pin = 10;
int in2Pin = 9;
int enablePin2 = 6;
int in1bPin = 5;
int in2bPin = 3;
int motorpins[] = {3, 5, 6, 9, 10, 11};

void setup()
{
pinMode(in1Pin, OUTPUT);
pinMode(in2Pin, OUTPUT);
pinMode(enablePin, OUTPUT);
pinMode(in1bPin, OUTPUT);
pinMode(in2bPin, OUTPUT);
pinMode(enablePin2, OUTPUT);

Serial.begin(9600);
}
void loop()
{
if (Serial.available() > 0) {
char c = Serial.read(); //gets one byte from serial buffer
int speed = Serial.parseInt();
if (c == 'a') {
analogWrite(enablePin, speed);
analogWrite(in1Pin, ! speed);
analogWrite(in2Pin, speed);
}
else if (c == 'b') {
analogWrite(enablePin2, speed);
analogWrite(in1bPin, ! speed);
analogWrite(in2bPin, speed);
}
}
return;

}

I think it's easier if you send the messages from Pd like this:
[print $1a(
and in the Arduino code do the following:

After the if(Serial.available() > 0) declare a static int temp_val;

after char c = Serial.read(); do this:
if((c >= '0') && (c <= '9')) temp_val = temp_val * 10 + c - '0';

then change if(c == 'a') to else if and do:

analogWrite(enablePin, temp_val);
analogWrite(in1Pin, ! temp_val);
analogWrite(in2Pin, temp_val);
temp_val = 0; // resets the temporary value

and do the same for b.

excellent, thanks will try it. I think "else if" is a much better solution, I am not really too adept yet with arduino, Thanks for your explanation!

You may try the software to split or switch your RS232 data http://www.eltima.com/rs232-switcher.html
Not sure, how it works with arduino, but still you can try.

wow, thanks Stanku that looks very interesting!