Using a puck.js device to receive and display temperature status obtained from another puck.js

I'm not sure I've seen anything specific, but I guess you have three options:

• Have the temperature Puck advertise its temperature, and have the second one occasionally wake up and listen
  
• Have the receiver Puck connect and request information from the temperature Puck
  
• Have the temperature Puck connect and 'push' data to the receiver Puck
  
  

I think either of those solutions works fine, although the first option might be easier to debug and also is probably more power efficient - especially for the sensor puck that you can't get to.

As an example of the first idea:

Sensor:

setInterval(function() {
  NRF.setAdvertising({
    0x1809 : [Math.round(E.getTemperature())]
  });
}, 30000);

Receiver:

var currentTemp = 0;
function getTemp() {
  NRF.findDevices(function(devices) {
    var found = false;
    for (var i in devices) {
      if (devices[i].name!="Puck.js e782") continue;
      var d = E.toString(devices[i].data);
      // index of 0x1809 in advertised data
      var idx = d.indexOf(String.fromCharCode(0x09,0x18));
      if (idx>=0) {
        currentTemp = d.charCodeAt(idx+2);
        found = true;
      }
    }
    if (found)
      digitalPulse(LED2,1,50); // green = good
    else
      digitalPulse(LED1,1,50); // red = bad
  }, 2000 /* receive for 2000ms */);
}


// look once a minute for temperature
setInterval(getTemp, 60000);

Right now it flashes green for 'got temperature' and red for 'unable to read temperature' - so it doesn't do anything with the temperature value, but it's easy enough to change.

The receiver won't be super power efficient, as it's listening for 2 seconds every 60 seconds. It should still last quite a while on a battery though.