Thank you it helps a lot.
But can you tell which widget should I use to send numeric value like 200 from Blynk to Arduino uno. I heard numeric input has a bug . So I want to use string input and convert it to numetic. But I dont find how I can do that
I think the issue of each digit being sent as it was inputted (in the iOS version of the app) was fixed, but there are simple workarounds if not.
The links in that topic probably answer your other question too.
I also want to use NewPing Libarary for ultrasonic sensor. And this libarary uses the Timer2 interrupt of Arduino UNO. Do it cause problem if I use Blynk timers with it?
I mean if I use blynk and NewPing libarary same time do their timers
The Sketch Builder examples are built around tasks rather than widgets, although the comments within the code explain what widgets to add to use the example.
The Numeric and Text input widgets are fairly new, and all of the Sketch Builder examples were written prior to their introduction, so you won’t find any examples for them.
The Virtual Pin Read example is probably as good as any to use with the Numeric Input widget. When you attached the widget to a virtual pin then the BLYNK_WRITE(vPin) call back will trigger automatically when the widget value changes. You can use the param.asInt() command to save the value from the widget into a variable (probably best to use a global variable rather than a local one).