Temperature Graph on a PCD8544 display, with DS18B20 temperature sensor

Using the Nokia 5110 display and the DS18B20 temperature sensor to make a simple temperature graph

LCD Wiring:

DS18B20 Wiring:

Source Code

SPI1.setup({ baud: 1000000, sck:B3, mosi:B5 });
var ow = new OneWire(B13);

var g, temp, history;

function onInit() {
  clearInterval();

  temp = require("DS18B20").connect(ow);
  g = require("PCD8544").connect(SPI1,B6,B7,B8, function() {
    setInterval(onTimer, 500);
  });
  history = new Int8Array(g.getWidth());
}


// create history points, one for each pixel on the LCD


function onTimer() {
  // Get the temperature
  var t = temp.getTemp();
  // Move our history back and add our new temperature at the end
  for (var i=1;i<history.length;i++)
    history[i-1] = history[i];
  history[history.length-1] = t;
  // function to convert the temperature to a position on the screen
  var tempToY = function(t) { return 30-t; };
  // draw the graph!
  g.clear();
  g.moveTo(0,tempToY(history[0]));
  for (i=1;i<history.length;i++)
    g.lineTo(i,tempToY(history[i]));
  // display on the screen
  g.flip();
};

onInit();