Triggering Synths with DigitalIn in SuperCollider

Wicked - there is no documentation of AnalogIn or DigitalIn, so knowing what they can actually do with examples is really needed:

Code i'm trying:

		// 1am anger.
		SynthDef(\shh, {
			arg out=~outBack, t_trig=0;
			var sound, env;
			sound = Mix(LFPulse.ar(110*[1,5/2],0.0,0.5,0.2));
			env = EnvGen.ar(Env.perc(0.02,0.2), t_trig);
			sound = Pan2.ar(sound * env,0.0);
			Out.ar(out, sound);
		}, [\tr]).add;


		~buttonMonitor = {
			var d0 = DigitalIn.kr(0); // Digital pin 0 - Button
			var d1 = DigitalIn.kr(1); // Digital pin 1 - Button
			var d2 = DigitalIn.kr(2); // Digital pin 2 - Button
			var d3 = DigitalIn.kr(3); // Digital pin 3 - Button

			SendReply.kr(Impulse.kr(10), '/buttonMonitor', [d0, d1, d2, d3]);
		}.play;


		~button1 = 0;
		~button2 = 0;
		~button3 = 0;
		~button4 = 1;

		// Listen to the buttons
		OSCdef('listenToButtons', {
			arg msg;
			// Buttons
			~button1 = msg[3].asInteger;
			~button2 = msg[4].asInteger;
			~button3 = msg[5].asInteger;
			~button4 = msg[6].asInteger;

			["Buttons: " ++ ~button1, ~button2, ~button3, ~button4 ].postln;
		}, '/buttonMonitor');



		{
			q = Synth(\shh);
 			q.set(\t_trig, Pfunc({~button3}));
		};

Trying to get any 'button' to actually trigger a sound, nothing seems to work and it's an endless hole of errors in the console.

Trying to also trigger one sound in a sequence of buffers, so each button is the next buffer number, which is as simple as saying, have a DigitalIn choose from an array of numbers.

Also, MouseButton is almost nothing like DigitalIn, in the sense that DigitalIn(0) is pin D0, but what are the extra values I can pass through to this like this example:

{ SinOsc.ar(MouseButton.kr(440, 740, 2), 0, 0.1) }.play;

How do you replace MouseButton with DigitalIn in this example?

Ok, four days into the Expo and I'd really love to introduce buffers into the code, the synths are ok, but could be improved with samples.

This is the code i'm running, I'm trying to get the analogin to chose the buffer number, but 'Index not integer' is my problem.

I found a crude way to change sounds on the fly without the bela exploding, but it means running the ugens for digitalin and analogin right in the synthdef.

SynthDef(\samplePlaying, {
	arg atk=0, sus=0, rel=3, c1=1, c2=(-1),
	buf=0, rate=1, spos=0, freq=440, rq=1, bpfmix=0,
	pan=0, amp=1, out=0;
	var sig, env, sound, sample, 
buffersAvailable=[0,1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19];
	sample = Select.ar( ((0.4).linlin(0.01, 1, 0, 19).nearestInList(buffersAvailable)), buffersAvailable);
	sound = b[\drum_kit][1 * sample];
	
	env = EnvGen.kr(Env([0,1,1,0], [atk, sus, rel], [c1,0,c2]), gate: 1 );
	sig = PlayBuf.ar(1, sound, rate*BufRateScale.ir(sound), startPos:spos);
	sig = XFade2.ar(sig, BPF.ar(sig, freq, rq, 1/rq.sqrt), bpfmix*2-1);
	sig = sig * amp;
	sig = Pan2.ar(sig, pan, amp);
	Out.ar(out, sig);
}).send(s);

Whats the approach I should be taking to trigger this synth when a button is pressed and to map a sensor to choosing a new buffer number?

Absolutely, I understand that writing software that is open-sourced and non-paid is time consuming and doesn't put food on the table, so I really appreciate your help on this.

I'll give Changed.ar a try with triggering.

An alternative way of asking this question, is how do we use DigitalIn to create a new synth and destroy the previous one - the machine i've built has a turnwheel that triggers a button with every rotation. I tried loading a buffer of 20 samples to trigger a new sample with every button press, but the walls i've hit are too tall for me to pass

nescivi Almost, but the error:

The preceding error dump is for ERROR: Primitive '_BasicAt' failed.
Index not an Integer

appears, as i can't seem to get this:

sample = Select.ar( ((0.4).linlin(0.01, 1, 0, 19).nearestInList(buffersAvailable)), buffersAvailable);

To be an integer, no matter what I've tried

Oh, but we don't have to use Demand at all do we

		(
		// Buffers/Sound files loaded from dictionary
		SynthDef(\samplePlaying, {
			arg atk=0, sus=0, rel=3, c1=1, c2=(-1),
			firstbuf=0, rate=1, spos=0, freq=440, rq=1, bpfmix=0,
			pan=0, amp=1, out=0;
			var sig, env, sound, sample;
		    var trig;
		    var buffersAvailable=(0..19).scramble;
			var bufseq;
			trig = DigitalIn.kr(0);
			bufseq = Dseq( buffersAvailable, inf );
			
                        /////////////////////
                        sample = AnalogIn.ar(0).linlin(0.01, 1, 0, 19); // Pick the buffer, based on Analog sensor
			/////////////////////
			
			env = EnvGen.kr(Env([0,1,1,0], [atk, sus, rel], [c1,0,c2]), trig );
			sig = PlayBuf.ar(1, sample, rate*BufRateScale.ir(sample), trig, startPos:spos);
			sig = XFade2.ar(sig, BPF.ar(sig, freq, rq, 1/rq.sqrt), bpfmix*2-1);
			sig = sig * amp;
			sig = Pan2.ar(sig, pan, amp);
			Out.ar(out, sig);
		}).send(s);
		);

nescivi interestingly, the analogIn can trigger the samples and cause a bunch of glitching - perhaps rounding would solve the issue?