A heartbeat is a POST request that's sent from an LTE Beacon to the Estimote Cloud over LTE. Its role is to regularly retrieve a beacon’s health data and make sure it’s up to date. It contains data such as the battery level, firmware version, or the beacon’s GPS coordinates. It also contains a unique hash of the micro-app currently running on a beacon. That way, we can make sure a beacon is running the most recently deployed micro-app.
The heartbeat is a system feature designed for health check purposes. It runs on LTE Beacons by default and cannot be disabled. If your use case requires obtaining similar readings from the LTE Beacon, e.g. frequent battery readings, motion data, or GPS coordinates, you can build a micro-app instead and load it on a beacon.
How often is a heartbeat sent? Can I customize the frequency?
A heartbeat occurs every 30 days by default. The first one happens before we even ship the beacon, and the next heartbeat follows at regular intervals. A new heartbeat will also be sent if a beacon is restarted, for example, when a battery runs out. The countdown until the next heartbeat will restart then.
It's also possible for an LTE beacon to send its heartbeat more frequently — every week or every day. You can switch between these three options by clicking the button on the side of the beacon. Keep in mind, however, more frequent updates will result in a quicker drain on your battery.
How can I check when my next heartbeat is due?
Open your Estimote Cloud dashboard, go to the LTE Beacons section and click on one of your beacons. On the list, you'll see the heartbeat frequency and also the approximate date and time of the next scheduled sync:
Note that information about heartbeat frequency is sent in the heartbeat itself. Because of this, the frequency displayed in the Cloud won't change immediately after you modify it on the beacon. It will, however, be updated the moment the next heartbeat arrives.
To visualize this, let’s have a look at the following timeline:
April 20th: Heartbeat interval is set to 30 days. Heartbeat arrives and Cloud informs you that the next one is due May 20th.
April 22nd: You change the interval on a beacon to 7 days. Cloud still shows that that next one is due on May 20th as it’s yet to receive an update.
April 25th: Cloud still shows the same information, no new heartbeat has been heard yet.
April 29th: A new heartbeat arrives, 7 days after you changed the interval. Cloud updates the information and informs you that the next heartbeat will be due on May 6th.