Features

Plaquette is an object-oriented, user-friendly, signal-centric framework that facilitates signal filtering in real-time. It is fully compatible with Arduino.

Object-oriented

Plaquette is designed using input, output, and filtering units that are easily interchangeable in a plug-and-play fashion. Units are created using expressive code.

For example, the code DigitalOut led creates a new digital output object that can be used to control an LED.

Arduino	Plaquette
Create digital output to control an LED:
`pinMode(12, OUTPUT);`	`DigitalOut led(12);`
Create digital input push-button:
`pinMode(2, INPUT);`	`DigitalIn button(2);`

User-friendly

Plaquette allows users to quickly design interactive systems using an expressive language that abstracts low-level functions. This allows both beginners and experts to create truly expressive code. For example, switching our LED object on or off can be achieved by calling: led.on(). Find out more about Plaquette’s base units by following this link.

Arduino	Plaquette
Turn LED on:
`digitalWrite(12, HIGH);`	`led.on();`
Check if button is pushed:
`if (digitalRead(2) == HIGH)`	`if (button.isOn())`

Signal-centric

Plaquette helps designers manipulate real-time signals from inputs to outputs. In Plaquette, signals are represented either as true/false conditions (in the case of digital binary signals such as those coming from a button or switch), or as floating-point numbers in the [0.0-0.1] range (ie. 0% to 100%) (in the case of analog signals such as those emitted by a light sensor, microphone, or potentiometer.) Because of this, there is no more need for users to perform counter-intuitive conversions on integer values.

Arduino	Plaquette
Check if button is released:
`if (digitalRead(2) != HIGH)`	`if (!button)`
Check if sensor value is higher than 70%:
`if (analogRead(A0) >= 716)`	`if (sensor >= 0.7)`

Signal Filtering

Plaquette provides simple yet powerful data filtering tools for debouncing, smoothing, and normalizing data. Removing noise in input signals can be as simple as calling a function such as debounce() or smooth(). Rather than guessing the right threshold for triggering an event based on input sensor input, one can use auto-normalizing filters such as MinMaxScaler and Normalizer.

Signals in Plaquette can easily flow between units, in a similar fashion to modern data-flow software such as Max, Pure Data, and TouchDesigner. While this can be achieved using function calls, Plaquette provides a special piping operator (>>) which allows data to be sent from one unit to another.

Arduino	Plaquette
Set LED to ON when button is pressed:
`digitalWrite(12, digitalRead(2));`	`button >> led;`
Set LED to ON when input sensor is high:
`digitalWrite(12, (analogRead(A0) >= 716 ? HIGH : LOW));`	`(sensor >= 0.7) >> led;`

Read Regularizing Signals to see how you can take full advantage of Plaquette’s signal filtering features.

Real-time

Plaquette avoids blocking processes such as Arduino’s (in)famous delay() by providing a set of timing units as well as time-based signal generators. As such, the processing loop is never interrupted, allowing interactive and generative processes to flow smoothly.

Plaquette forbids the use of blocking functions such as Arduino’s delay() and delayMicroseconds(). Rather, it invites programmers to adopt a frame-by-frame approach to coding similar to Processing.

Compare the following attempt to make an LED blink when pressing a button in Arduino, versus Plaquette’s real-time approach:

Arduino

Plaquette

int buttonPin = 2;
int ledPin = 12;

void setup() {
  pinMode(buttonPin, OUTPUT);
  pinMode(ledPin, OUTPUT);
}

void loop() {
  // Button is checked once per second.
  if (digitalRead(buttonPin) == HIGH) {
    digitalWrite(ledPin, HIGH);
    delay(500); // do nothing for 500ms
    digitalWrite(ledPin, LOW);
    delay(500); // do nothing for 500ms
  }
}

DigitalIn button(2);
DigitalOut led(12);

// Square wave 1 second period.
SquareOsc oscillator(1.0);

void begin() {}

void step() {
  // Button is checked at all time.
  if (button)
    oscillator >> led;
}

Arduino compatible

Plaquette is installed as an Arduino library and provides a replacement for the core Arduino functionalities while remaining fully compatible with Arduino code. Seasoned Arduino users should consult the Advanced Usage section for some tips on how to integrate Plaquette into their existing code.

if (Serial.read() == 'T')
  led.toggle();

Warning

Plaquette is still at an experimental stage of development. If you have any issues or questions, please contact the developers, or file a bug in our issue tracker.