Dmitriy,
In your code, in the example your referenced, I don’t understand why there appears to be a missing Virtual pin reference, like V3 or something.
Does …Blynk.virtualWrite (ledPin2, led2value); = Blynk.virtualWrite (V3, led2value); ??
(Instructables :How to use virtual pins?)
In a comment made by Costas he said we should avoid using HIGH and use 255. Are these interchangeable terms and conditions?
int prev = HIGH;
void loop()
{
Blynk.run();
int led2value = digitalRead (ledPin2);
if (led2value != prev){
Blynk.virtualWrite (ledPin2,led2value);}
prev = led2value;
}