Hi,
I am controlling a water pump through Blynk IOT. Everything works as I expected. I would like to add on a feature. I am not sure of its feasibility. But I thought of checking with the community.
When there is power cut in the middle of pump running, the device goes off and the pump. The blynk app shows the device is disconnected or offline (green circle), but my LED status (blue circle) which is driven by a virtual pin stay on.
Is there a way to turn it off using heartbeat signal?
You should take a look at the data invalidation rules in the advanced section of the datastream setup.
This will allow you to automatically change the datastream value to 0 if an updated value hasn’t been received from your device for a specified period of time.
Pete.
Thank you for your answer. Currently, my code sends data only during switching (On → Off or Off → On). If I have to use this invalidation rules, then I should send the data for every fixed duration when the pump is on. Otherwise, it would turn to 0 even if pump is on. Am I right?
Correct. As you used the word “Heartbeat” I assumed that meant you were sending the current value on a regular basis.
Can’t think of an alternative suggestion in your case.
Pete.
Thx All - this is really good to know!
A related question - is there a way to time stamp & display when this (IOT device) off-line event actually happens? Basically a terminal display (line) in the App showing something like it’s been XXX minutes since your device last provided an update.
The device Notifications area in the app and web console show when the device went online and offline.
Pete.
I expected something invalidation rules of virtual pin based on heartbeat (timeout). I face a strange issue in one of my virtual pins. It is actually an integer with min and max set as 0 & 1 respectively. It is written by Node MCU and gets reflected in app as LED. I also plot the data. For some unknown reason it stays at 0.75 for 20 mins (7:15 - 7:35) when it is actually turned off at 7:15. The automation was triggered at 7:15 which is an expected behaviour, but it got triggered again at 7:35 when it came to 0 from 0.75. It happened previously as well. At that time, it stayed at 0.5 at one instance and 0.667 at another instance.
This is because the value is being averaged over the relevant time period.
As you’ve not stated which widget, or which dashboard (mobile or web) you’re referring to, and which settings you’ve selected for the widget, it’s difficult to suggest a solution.
Pete.
I tried to include couple of pics but I was blocked since I am posting for the first time. Sorry for the lack of information. I am using web console. You are right, there were three On pushes (green box) and 1 Off push (red box) at 7:15 PM as recorded by automation. So, the average is coming to 0.75. But I selected Max in the chart settings (brown box). May be, still it has to calculate average against 7:15 PM because of multiple values?
My main concern is about the automation getting triggered at 7:35:47 PM. I expect the nodemcu to write ‘0’ at V2 20 mins after On command (at 7:15:46 PM). But it shouldn’t trigger the automation as it is already turned off at 7:15:53 PM. The automation settings for off is provided in the orange box. Off automation got triggered at 7:15:53 PM because of manual command and then it was not turned on. So, I expected the virtual pin to stay at ‘0’ regardless of the value I see in the chart as it is an Integer (blue box).
