Feedback from Project

Since I plan on using Blynk remotely from my project, I have no idea if a light that I have turned on with a button widget is actually on or not. Wouldn’t it be nice if when I pushed the button, the color of the widget did not change until the widget received feedback from the project that the message to either turn on or off the device had been delivered. That way, when I push the button, I would know if the action had been carried out by my project.


Yeah, this is something we will add in very nearest releases. It’s really very needed feature!
Right now you can hack it by writing code that will check the pin status and write it to Value Display or LED via Virtual Pin. Again, it’s a hack :wink:


I am using iPhone to run the Blynk-application and still patiently waiting for the feedback function. When will the “color change after feedback” or something similar be implemented so we can be 100% sure that the message went through?


Why not program this in yourself?

I have a LED on a virtual pin, then once the remote controller has performed its action it responds back to the dashboard and turns the LED on - I also have an additional Hall effect sensor on my one device that senses if the gate is in an open or closed state, this was needed as I have some legacy remotes in parallel as “backup”.

I was wondering what the status of this solution might be? Back in May it was suggested that it would happen in the “very nearest releases”. In my case it would be preferable to have the color circle on the widget change states once the action is carried out. So, if I push the button, once the feedback is received that the action was carried out, the colored circle would appear on the button widget.


We changed our priority list based on users feedback. Now it looks like that:

  • Sharing; (~1 month)
  • Bluetooth; (~1 month)
  • GPS or state handling;

ok, thanks for the update


do you have an example of this code? I would like to do as Pavel suggests and check the status of a pin and then write that value to an LED widget via a virtual pin.

I don’t have an example handy but it really is as simple as writing to an unused virtual pin and then assigning an LED widget in the app to that pin.
When the LED is set high in the device, you write the same value to the vpin and then the led in the app will light up
I’m doing exactly this kind of thing in setup I’m working on now. I’ll have three devices all running the same code, controlling some lights. Whenever the inputs or outputs change I write to some virtual pins that are only used in the app to show status.

Ok, thanks for the reply. I am just looking to have a button and then a single LED on a virtual pin show if the button is “on” or “off”

@mpo881 don’t know how far you have got but something like this (plus Blynk stuff based on your hardware setup):

// add all the normal Blynk stuff depending on your hardware setup

#include <SimpleTimer.h>
SimpleTimer timer;

byte val = 0;             // variable to store the button status
byte buttonD5 = 5;        // button / switch on digital pin 5
byte led = 2;             // the pin that the LED is atteched to, digital pin 2

void setup() {
  pinMode(led, OUTPUT);      // initalize LED as an output
  pinMode(buttonD5, INPUT);    // initialize button / switch as an input
  timer.setInterval(3000,  CheckButton);  // check button state every 3 second

void CheckButton(){    // done every 3 seconds
  byte val = digitalRead(buttonD5);   // read button value
  if (val == HIGH) {           // check if the sensor is HIGH
    Blynk.virtualWrite(V3, 255);  // turn app LED on V3 ON
  else {
        Blynk.virtualWrite(V3, 0);  // turn app LED on V3 OFF

void loop() {;   // need all the regular Blynk stuff in definitions and setup;

Thank you very much. I will look over what you sent and give it a try.:grinning: