Offline/Online handling when only using HTTP API to communicate from device

I am using cellular device to communicate to the server and App through HTTP API commands. It works well but I have not yet found any way to get a notification or similar if my device stops pushing data to the server. Is there any way to send a “Heartbeat” to Blynk through HTTP API?

An alternative for me could be to make the eventor capable of having this functionality. With the eventor I would like it to be possible to say that if there has been no updates on e.g.V3 for X minutes (Where X minutes should also be possible to set from a Virtual pin), then send Notification.

Anyone have a solution?

The original purpose of HTTP protocol was for the next scenario: open connection, send data, close connection. Since HTTP 1.1 version most clients / servers now support persistent connections. So flow is next: open connection, send data. Connection is closed only during client/server close(), due to error or network issue.

Those 2 flows are typical use cases for HTTP protocol.

Now, with cellular network it doesn’t make big sense to hold the persistent connection. Because cellular network is not very stable (can drop connection often), persistent connection eats battery and typical cellular scenario is to wake up, send data and close.
In that flow online/offline events don’t make large sense. BEcause online periods are short and absence of the connection is the normal situation. So that’s why Blynk doesn’t manages online/offline events for HTTP connections.

What are you looking is something we call Rule Engine (in the new blynk 2.0) - “If no data for 1 week - send notification”.

Old Eventor doesn’t support that.

Thanks a lot for the feedback. Yes all I need is some way the app knows that my device has stopped pushing data.

The closest I have managed is to send timestamp for my data so that I can see when it was last updated. But I cant connect this timestamp to the current time and get notifications if current time is X time larger than timestamp…

When can we try out the 2.0? :blush: