Time Accuracy | Time Drift in IoT devices

Living in the world of connected devices and utilising Internet in our everyday life, the essence of time accuracy is important to all of us and more often than not, the accuracy of time actually determines if a device is functioning properly for us or more, it affects the usefulness of the devices to us in many scenarios.

Take for example, a connected watch like iWatch or Android watch especially when it’s used in advanced countries like Japan where the train systems abide very strictly to schedule is crucial to catching a train to work on time. A slight inaccuracy of a couple of minutes could easily cause them to miss a trip. Similarly for airplanes/airports, similar concept as well.

In the world of datacenters, mission critical systems are very time-dependent as it provides services real time and time accuracy is of utmost importance to them as well.

So as a consumer, does it matter to you in your homes or offices? Of course! Imagine your houses and offices have got smart sensors or devices that are time driven to shutdown, it could easily mean 2 things to you: Energy usage and Habits.

Point 1: Energy Usage

Imagine if today your IoT controller eg Vera Plus do not have a proper time sync with Internet time and it depends on the system default time to calculate the time of inactivity say in a scene whereby the lights will turn off after 5 minutes of inactivity and because of time drift (see wiki), the actual time to do this could be a couple of minutes off and if you do not visit your IoT controller interface much, you could potentially use unnecessary energy.

Point 2: Habits

Because of point 1, sometimes time drifting can be to a substantial extent that you can actually doubt if your lights or sensors are working and that could change your habits instead of IoT devices suiting to your habits.

So it’s important to have time servers to help you keep track of time in your geographical region. In VeraPlus, there is already a NTP mechanism to do time synchronisation but it points to openwrt by default. For my situation, it didn’t really do well for me as I’ve experienced quite a number of drifts (could be due to my Internet) but I’ve since changed to a local NTP server to serve the time sync and so far so good. Everything seems fine. To change your NTP settings in your Vera UI7, follow the steps below:

Step 1: SSH into your Vera PlusĀ 

Login to your Vera Plus and go to Settings / Customer Care. Click on Enable on tech support. You should see a string like below:

Using a client eg Putty, key in your IP address and use “remote” as your login name and the password seen below in grey (before word SSH) to login.


Step 2: Edit your ntp configuration file

Perform this command: vi /etc/config/ntpclient to edit your time servers configuration. See below. Google for vi command for editing.


Step 3: Restart your NTP service and you are done!

Enter this command: /etc/init.d/ntpclient restart

So that’s all to ensure that your time service is up to date. More sharing on next round!

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