This tutorial will help you with creating Events in Device Templates
Getting Started -> Events
Events are used to track, log, and work with important events that happen on the device.
Events are also used for notifications which can be sent over email, delivered as push notifications to user's smartphone, or sent as an SMS.
Events are pre-configured in Blynk.Console and can be triggered with a Events Firmware API from device or using Events HTTP API.
Examples of an Event:
- Log a moment when a temperature reached a certain threshold and send a notification to selected users
- Track total working hours of the device. If it approaches or goes beyond a max value, you would need to notify technical support so that they can replace the device or provide warranty service
Events list in the template
There are three types of Events in Blynk:
- System Events: Default Blynk platform events.
- Custom Events: Events you can create and configure for your needs
- Content Events: Informative events that are shown separately in the app
You can't delete the system events, but you can configure them.
This event is used to track when devices goes online and offline.
In some cases you would need to ignore offline state for a certain period of time. For example, if your device is mostly offline (or in deep sleep) and only wakes up every hour to send the data.
This is a system event to track firmware update. It can't be configured
These are Events you can configure based on what your device do. Read these articles to start logging events and sending notifications:
Go to Template -> Edit -> Events tab.
- 1.Click Add New Event
- 2.Name the first event with the name Hello
- 3.Click Create (the event will appear in the Events tab list)
- 4.Repeat the previous step for the second event with the name Error
- 5.Click Save to save and apply the changes made (select Update active device this time)
Note that each event has
EVENT_CODE. This event code will be used in firmware API or HTTPS API
- 1.Create a new Event named
High temperaturewith code
- 2.Use the
Blynk.logEvent(event_code)firmware API command to trigger new event
if (temperature > 35)
When this code worked, an Event will be logged and the system will act accordingly to the Event setup (render on timeline, send notifications, etc.)
Avoid logging an event too many times not to hit daily limits. You can use timers or flags to mark the already sent events. Check this article on how to avoid spamming the server with events
You can change the description of the event when it's rendered on the timeline in Blynk.Console and in Blynk.Apps. For example, you can include the current data
if (temperature > 35)
Blynk.logEvent("event_code", String("High TemperatureDetected! Tº: ") + temp);
To log an event use GET request:
To add custom description to the event, use this GET request
You can test the Event creation by sending it from Device using Blynk.Edgent firmware API, or with REST API.
Blynk.logEvent("event_code", "optional message");
For this tutorial you would need to use hello as a name. Here is a pseudo code:
Optionally, you can send a custom description with the event. This description will be rendered on Device Timeline.
Blynk.logEvent("hello", "Hello World,") ;
- 1.Navigate to the Device
- 2.Click on its name
- 3.Open Device Info tab
- 4.Find Auth Token there and click on the icon to copy it to the clipboard
Device Info tab
Auth Token. Click copy pictogram here
Now make an HTTP request with the tools you use for that. Make sure to change the
YourAuthTokento the one you copied in the previous step.
You can even use your browser for that. Just put it in the URL field and press Enter.
Repeat the same with
You should see 2 events on the timeline! If you set up notifications, they should have been delivered as well.
- You can send only 100 events per devices per day (Adjustable in Business Plan)
- When the limit is reached you'll see the notification on the UI in the Device Timeline section
- The maximum description length for the event is 300 characters