How to use timers in code

If you are looking for a Timer Widget (from Blynk Legacy), it's not here. Timer Widget was replaced with "Wait" action in Automations

As you may already know, hardware can send various data types to the Widgets over the Virtual Pin like this:

sensorData = analogRead(A0); // this is an example of reading sensor data
Blynk.virtualWrite(V5, sensorData);

Don't put Blynk.virtualWrite(V5, sensorData); in the void loop ()!

If you put it code into a void loop() it will execute "gazillion" times. This will spam the Blynk.Cloud with thousands of messages from your hardware. When it happens, Blynk.Cloud will cut off the connection between your hardware and server.

Use Timers

Blynk Library offers a built-in Blynk.Timer feature to send data in intervals. It allows you to send data periodically with given intervals and not interfere with other Blynk library routines.

Blynk Timer is based upon SimpleTimer Library, a well-known and widely used library to time multiple events on hardware.

  • BlynkTimer is included in Blynk library by default and there is no need to install SimpleTimer separately or include SimpleTimer.h separately.

  • A single BlynkTimer object allows to schedule up to 16 timers

  • Improved compatibility with boards like Arduino 101, Intel Galileo, etc.

  • When a timer struggles to run multiple times (due to a blocked loop), it just skips all the missed intervals and calls your function only once. This differs from SimpleTimer, which could call your function multiple times in this scenario.

For more information on timer usage, please see: http://playground.arduino.cc/Code/SimpleTimer

This is an example code on how to send data every second with a timer. Check full example sketch here.

// Declaring a global variabl for sensor data
int sensorVal; 

// This function creates the timer object. It's part of Blynk library 
BlynkTimer timer; 

void myTimer() 
  // This function describes what will happen with each timer tick
  // e.g. writing sensor value to datastream V5
  Blynk.virtualWrite(V5, sensorVal);  

void setup()
  //Connecting to Blynk Cloud
  Blynk.begin(auth, ssid, pass); 
  // Setting interval to send data to Blynk Cloud to 1000ms. 
  // It means that data will be sent every second
  timer.setInterval(1000L, myTimer); 

void loop()
  // Reading sensor from hardware analog pin A0
  sensorVal = analogRead(A0); 
  // Runs all Blynk stuff
  // runs BlynkTimer

A single BlynkTimer instance can schedule many timers, so most likely you will only need one BlynkTimer in your sketch.

Last updated