Make water level monitoring with gpios pins

[PeteKnight]

You obviously didn’t understand the role of BlynkTimer.
You shouldn’t be using blocking delays in your code, and this…

@Karan_Sethi

  updateTankLevel();

  // Send tank level to Blynk every 10 seconds
  Blynk.virtualWrite(V1, tankLevel);

shouldn’t be in your void loop.

Also this…

@Karan_Sethi

  if (digitalRead(SENSOR_4) == LOW) {
    tankLevel = 100;
    // Trigger event in Blynk if tank level is 100%
    Blynk.logEvent("water_tank_full");

will log an event once every second while the tank is full, which will use up your daily allowance of events within 100 seconds.
You should read this…

Events, Notifications and the use of "Flag" variables

Update 19th May 2022 - you’ll see references to a limit of one event per minute in this tutorial. It appears that this limit has now been removed. I’ve not yet tested this myself, and when I do I’ll update the tutorial to reflect my findings. I’m seeing quite a few posts from people who are finding it difficult to get notifications working in Blynk IoT, and who don’t understand how to use “flag” variables to limit the number of notifications that are sent for any given alert situation. I thoug…

You might so want to redact your Auth token and WiFi password from your sketches.

Pete.