const serviceUuid = '00001901-0000-1000-8000-00805f9b34fb';

​

let myCharacteristic;

let myValue = 0;

let myBLE;

var timestamp;

​

function setup() {

  // Create a p5ble class

  myBLE = new p5ble();

​

  createCanvas(200, 200);

  textSize(20);

  textAlign(CENTER, CENTER);

​

  // Create a 'Connect and Start Notifications' button

  const connectButton = createButton('Connect and Start Notifications')

  connectButton.mousePressed(connectAndStartNotify);

​

  // Create a 'Stop Notifications' button

  const stopButton = createButton('Stop Notifications')

  stopButton.mousePressed(stopNotifications);

}

​

function connectAndStartNotify() {

  // Connect to a device by passing the service UUID

  myBLE.connect(serviceUuid, gotCharacteristics);

}

​

// A function that will be called once got characteristics

function gotCharacteristics(error, characteristics) {

  if (error) console.log('error: ', error);

  console.log('characteristics: ', characteristics);

  myCharacteristic = characteristics[0];

  // Start notifications on the first characteristic by passing the characteristic

  // And a callback function to handle notifications

  myBLE.startNotifications(myCharacteristic, handleNotifications, 'uint16');

  // You can also pass in the dataType

  // Options: 'unit8', 'uint16', 'uint32', 'int8', 'int16', 'int32', 'float32', 'float64', 'string'

  // myBLE.startNotifications(myCharacteristic, handleNotifications, 'string');

}

​

// A function that will be called once got characteristics

function handleNotifications(data) {

  var delta_ms = millis() - timestamp;

​

  console.log('data: ', data.toString(16), 't = ', delta_ms) ;

  myValue = data;

}

​

// A function to stop notifications

function stopNotifications() {

  myBLE.stopNotifications(myCharacteristic);

}

​

function draw() {

  background(250);

  // Write value on the canvas

  text(myValue, 100, 100);

}

​

​

/*

​

function handleNotifications(theData) {

  console.log(theData.length);

  if(theData.length==12) {

              var values = [];

              for(var k=0;k<theData.length;k+=2) {

                  values.push(theData.readInt16BE(k, 2)); // signed int

              }

        debug('data',

              peripheral.advertisement.localName+"\t"+values[0]+

              ", "+values[1]+

              ", "+values[2]+

              ", "+values[3]+

              ", "+values[4]+

              ", "+values[5]);

​

              var n = Math.pow(2, 16);

              var rad = 0.0174533;

              var ax = (values[0] * 4.0)/n;

              var ay = (values[1] * 4.0)/n;

              var az = (values[2] * 4.0)/n;

​

              ex = rad * (values[3] * 360.0)/n;

              ey = rad * (values[4] * 360.0)/n;

              ez = rad * (values[5] * 360.0)/n;

  console.log(theData);

  }

}

​

*/