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How can I use the Serial Opcode to trigger a sound from an Arduino?

#1

Edit
I was originally trying to do something else, but when I tried to simplify my problem I ended up trying to play a sound in cabbage that was triggered by a button press from an Arduino device. Hence I had to update the title of this topic.

I have two small Csound programs that run fine independently of one another, but not together.
The first Program reads a value using the serial opcode, I have it hooked up to an Arduino and when I press a button it prints 1, and when I release it, it prints 0. The code looks like this

//Start Serial Communication
iSerialPort	serialBegin	"/COM3", 9600

//Read the values into a slower k-rate variable
kType serialRead iSerialPort

printks("\nValue is %d", 0.001, kType)

The second allows me to get input from my microphone and plays it back to me, it records when I press the button and stops recoding for the second press. The Sampler Opcode works fine, and the rest of the code looks like this.

kTrig = chnget:k("record")    
kSpeed = chnget:k("speed") 
kSampleLength = chnget:k("sampleLength")
kSpeed = 1

a1, a2  in

aOutput Sampler (a1 + a2), kTrig, kSpeed, kSampleLength, 1

aOutput *= chnget:k("gain")

outs aOutput, aOutput

The Problem is when I attempt to combine them I get crashing, and Csound doesn’t read anything from my mic. If I look at the settings in cabbage, I can see input being received from my microphone before I run anything with the serial opcode but after I run it the input stops receiving anything until I plug in and out my Arduino.

The Combined Code Looks like this

//Start Serial Communication
iSerialPort	serialBegin	"/COM3", 9600

//Read the values into a slower k-rate variable
kType serialRead iSerialPort


printks("\nValue is %d", 0.001, kType)


kTrig = kType //chnget:k("record")    
kSpeed = chnget:k("speed") 
kSampleLength = chnget:k("sampleLength")
kSpeed = 1

a1, a2  in

aOutput Sampler (a1 + a2), kTrig, kSpeed, kSampleLength, 1

aOutput *= chnget:k("gain")

outs aOutput, aOutput
#2

You see it’s the input that is causing the problem? Can you do:

a1, a2 init 0

Jut to see if it behaves the same. Of course you’ll get no input, but let’s see if it still crashes…

#3

I think I may have narrowed it down to a the serialRead.
I have replaced the output with a simple oscillator.

in my Arduino code, I am only writing once, when I press the button. So I think what is happening is the Csound code is looping back around to serialRead and waiting for more input.

The problem is if I constantly write values to the stream there is a huge delay of up to 10 seconds before Csound picks up the new value, I think it is caused by a big backlog of data in the stream.

So I am a bit stumped on how to find a way around this, The way I would think is to check in Csound if there is anything in the stream, but I am unsure of how to do that there doesn’t seem to be an opcode to check id the serial port has no data in it.

//Start Serial Communication
iSerialPort	serialBegin	"/COM3", 9600

//Read the values into a slower k-rate variable
kType serialRead iSerialPort

//49 is the ascii code for "1"
if(kType == 49) then
	kEnv madsr .1, .2, .6, .4
    aOut vco2 0.5, 440
    outs aOut*kEnv, aOut*kEnv
endif
#4

I don’t think the serialRead opcode could be blocking. That would be crazy.

#5

In the simplest terms, what I am trying to achieve at the moment is to play a sound when I have the button on the Arduino pressed, and stop it when it is released.

#6

Try:

//49 is the ascii code for "1"
if(kType == 49) then
    aOut vco2 0.5, 440
    outs aOut*.5, aOut*.5
endif
#7

Same thing seems to happen, Every time I press the Button I get a little blip of a sound that lasts less than a tenth of a second.

#8

Sounds like your button is sending a single 1 followed by a zero very shortly afterwards. Just do this and see what you get:

printk2 kType

I imagine you get something like:

1
0
#9

Can you show your arduino code?

#10

Yes Arduino code looks like this

int button = 4;

int lastState;
int currentState;

void setup() {
  // enable serial communication
  Serial.begin(9600);
  pinMode(4, INPUT);

}

void loop() {
      currentState = digitalRead(4);
      
      if(currentState != lastState){
        Serial.write("1");
      }
       lastState = currentState;
}

the monitor in the Arduino prints a 1 every time i press the button

#11

And what happens when you do this? What does Csound show?

#12

image
image823Ă—335 44 KB

It seems to Only Print the first Time I press The Button?

#13

And if you take out everything apart from the Arduino code, does it still only print once? I’m just trying to figure out if there is something messing it up…

#14

But hold on, your Arduino code will always write 1? You only ever write one? Should you not reset it at some point back to 0?

#15

Yes actually I probably should change it back, Ill do that now.

If I change all the code to this

//Start Serial Communication
iSerialPort	serialBegin	"/COM3", 9600

//Read the values into a slower k-rate variable
kType serialRead iSerialPort

printks("\nValue is %d", 0.001, kType)

It prints every time i press the button.

#16

Yes because that code prints all the time. printk2 only prints when the value changes. Also, Why are you sending a char? Why not just do:

Serial.write(1);

Does that not work?

#17

When I just send it a 1, it comes up as that little square character in the serial monitor, I think serial.write takes a char.

I have updated the Arduino code to this

  currentState = digitalRead(4);
  
  if(currentState != lastState)
  {
    if(currentState == 1)
    {
      Serial.write("1");
    }
    else
    {
      Serial.write("0");
    }
  }

and now this code

//Start Serial Communication
iSerialPort	serialBegin	"/COM3", 9600

//Read the values into a slower k-rate variable
kType serialRead iSerialPort

printk2 kType

Prints 49 on button press and 48 on release.

#18

So you’re good to go :+1: or?

#19

Nope, it still just plays for a split second. I am convinced that the serial read is blocking it.

#20

My Most recent attempt plays an awful sound when I release the button that doesn’t stop until I unplug the Arduino of force close cabbage.

Arduino Code

int button = 4;

int lastState;
int currentState;

void setup() {
  // enable serial communication
  Serial.begin(9600);

  pinMode(4, INPUT);

}

void loop() {
  currentState = digitalRead(4);

  if(currentState != lastState)
  {
    if(currentState == 1)
    {
      Serial.write("1");
    }
    else
    {
      Serial.write("0");
    }
  }
  lastState = currentState;
}

Csound Code

<CsoundSynthesizer>
<CsOptions>
</CsOptions>
<CsInstruments>
sr = 44100
ksmps = 500 ; the default krate can be too fast for the arduino to handle
0dbfs = 1

instr 1

//Start Serial Communication
iSerialPort	serialBegin	"/COM3", 9600

//Read the values into a slower k-rate variable
kType serialRead iSerialPort

printk2 kType

kAmp init 0;

if(kType == 49) then
    kAmp = 0.5
elseif(kType == 48) then
    kAmp = 0
endif

    aOut vco2 0.5, 440
    
    outs aOut * kAmp, aOut * kAmp

endin
</CsInstruments>
<CsScore>
i 1 0 z
e
</CsScore>
</CsoundSynthesizer>