Strange behaviour when using Terminal widget with iOS


@Eugene I guess this is one for you.

Summary of the Issue
When sending regular data (every 10 seconds or so) to the terminal widget from hardware, the widget behaves as expected.
However, if the data is sent less frequently then then when the the iOS device is screen locked, left for a few minutes, then unlocked again, the data in the Terminal widget is repeated - sometimes multiple times.
Putting the Blynk app into edit (stopped) mode then immediately back into run mode restores the terminal widget data to what it should be - without the duplicated lines of data.

This screenshot shows the duplicated data…


and this shows the same data after the widget has neen stopped and started again…

Based on testing with several users, the issue appears to affect both local and Blynk cloud servers and the current iOS app version of 2.25.0 (3) and the beta version of 2.26.0 (2).

The data that’s being repeated isn’t being sent multiple times. It seems that when the app ‘wakes up’ from ruining in the background some sort of refresh refresh from the server is being done, which seems to be causing the problem.

Further information
It seems that the issue was raised here, over a year ago, but the description of the problem wasn’t very detailed:

This thread has much more detail, although it began by raising two issues then by about post number 38 began focusing on this duplication of terminal data in more detail:

This latest topic is a bit of a time-consuming read, but includes code that can be used to replicate the issue.
Both @877 and myself have almost identical results, so it seems it’s fairly easy (if a little tedious because of having to wait for a few minutes each time) to replicate.

If you want any assistance with testing a beta fix then I’d be happy to help.

Over to you…


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Terminal repeating...and lots of connecting to server messages

Guys, please check how it goes with latest beta 2.26.0 (4) build
Make sure you are on the Blynk Cloud server

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Initial tests are looking good.
I’ll do some more detailed testing tomorrow.




I’ve been doing more testing and everything seems fine, excpet that on two occasions the terminal has been blank when re-opening the app.
I’ve been struggling to reproduce this, but so far haven’t seen a pattern. The first time was after leaving the app overnight, the second time was after just an hour. It also cleared once when I edited the terminal widget, but on other occasions when I’ve edited the widget the contents didn’t clear.

I know this sort of feedback isn’t very helpful, but maybe it means more when you look at the code?




Hi both @Eugene and @PeteKnight ,

Apologies I did not get notified of activity on this thread, I have been wondering if it was getting looked at.

I’m more than happy to try latest iOS beta 2.26.0 (4) build if it can be provided.

@PeteKnight with my current code I often come back to the project and the terminal is blank, this is with the following function still running (I guess you removed that).

// a function called every <10 seconds to keep terminal awake, to prevent duplicate entries
void keep_terminal_awake()
  Blynk.virtualWrite(V1, "\b"); // Write nothing (backspace) to the terminal widget on V1

Currently I am using the required Blynk Cloud Server (as I am going to give Node Red a try after reading Pete’s posts on it :smile: )