SuperCollider: Light Dependent Resistor

This example shows how a single sensor can be streamed via serial data from the Arduino to SuperCollider.

Breadboard Circuit

The breadboard circuit is the same as in the first Arduino sensor example:

Arduino Code

For the SC example, serial data is sent in a simple way. The additional scaling is optional, but makes it easier to process the data in SuperCollider.

void setup() {

   Serial.begin(9600);
}

void loop() {

 int sensorValue = analogRead(A0);

 // scale to 0..1
 float voltage   = sensorValue/1024.0 ;

 Serial.println(voltage);

}

SC Code

On Linux, the Arduino's serial interface can be found in the terminal:

$ ls -l /dev/ttyACM*

On the SC receiver end, a serial port object is initialized with the matching serial interface:

(
p = SerialPort(
  "/dev/ttyACM0",
  baudrate: 9600,
  crtscts: true);
)

A control rate bus is used to visualize the received data and make it accessible to other nodes:

~sensorBUS = Bus.control(s,1);
~sensorBUS.scope;

The actual receiving and decoding of the data happens inside a routine with an infinite loop. It appends incoming characters, until a return character (13) is received. In this case, the assembled string is converted to a Float and written to the sensor bus:

(
r= Routine({
    var byte, str, res;
    inf.do{|i|
        if(p.read==10, {
            str = "";
            while({byte = p.read; byte !=13 }, {
                str= str++byte.asAscii;
            });
            res= str.asFloat;

            // ("read value:"+res).postln;

                    ~sensorBUS.set(res);
        });
    };
}).play;
)

External Resources

The SuperCollider Tutorial by Eli Fieldsteel shows a similar solution for getting Arduino sensors into SuperCollider via USB.