Can not send float variable to Blynk IOS app


I am using ESP-01 and want to send float data(for example, 0.05) to Blynk IOS app (ver: 2.23.0(4)) but it does not work with float. If I use integer variable it works fine.

Here is the code:

float Result = 0.05;
  Blynk.virtualWrite(V5, Result);

If I declare Result as Int type(for ex, 5) it works fine.

What should I done to fix it?


What sort of widget is V5?

Widgets like Value and Labelled Value have the ability to define how your data is displayed…

Next formatting options are supported:

`/pin/`  - displays the value without formatting (12.6789)

`/pin./`  - displays the value without decimal part (13)

`/pin.#/`  - displays the value with 1 decimal digit (12.7)

`/pin.##/`  - displays the value with two decimal places (12.68)

So, if you have it set to /pin./ then you’ll only see integer values displayed, even if you’re sending float data.


Hi! I am using /pin/

Looks like it is correct.

I thought may be I have an old Arduino IDE board version(it was 2.4.0) and now I set up 2.4.2


but nothing has changed :frowning:

Define “does not work”… wrong value,? no value? seemingly random characters?

And as already asked, please confirm what widget is on V5?

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Yes, widget is on V5! It is Labeled Value widget.

I want to add 0.01 to float Result by pressing the hardware button on breadboard. I set Result to initial value = 2.

So, if i press first time I should see 2.01 in app, second time - 2.02 and so on. But I just see 2 in spite of I pressed button

If I add 1(integer) it counts in correct way and I see right result.

I think you need to post your full code (correctly formatted of course).


Have you confirmed that your code is calculating the floats correctly by printing the result to your serial monitor?

yes, I confirm it calcs correctly.

Here is the code

#include <ESP8266WiFi.h>  
#include <ESP8266WiFiMulti.h>
#include <ESP8266mDNS.h>
#include <ESP8266WebServer.h>
#include <BlynkSimpleEsp8266.h>

const byte CounterPin = 2; 
int CounterState; 
float Result =2.00;
volatile byte interruptCounter = 0;

char auth[] = "My_Token"; 
char ssid[] = "My_SSID";
char pass[] = "My_psw";

void handleInterrupt() {
static unsigned long last_interrupt_time = 0; 
unsigned long interrupt_time = millis(); 

if (interrupt_time - last_interrupt_time > 500) 
last_interrupt_time = interrupt_time; 


void setup() {

Blynk.begin(auth, ssid, pass);
pinMode(CounterPin, INPUT_PULLUP);
attachInterrupt(digitalPinToInterrupt(CounterPin), handleInterrupt, FALLING);

void loop() {;


It never fails… almost no one reads the Welcome Topic before posting here (despite it being a universal forum requirement) so they just don’t get it :disappointed:

@bavspb I fixed your last post for you

1 Like


I just added in a simple test (to one of my existing projects) to emulate your count up… and it is working just fine for me in both Android and iOS on a Labeled Display Widget set for /pin.##/

float Result = 2.00;


09 46
… and counting…

Since you are using BLYNK_READ() are you sure you set your display widget to a reading rate and not PUSH?

1 Like

I have exactly the same screen with settings as you attached besides Input. I gave V5 pin. So it should work but does not

Local Server or Cloud?

What version Blynk Library?

I use cloud

Blynk 2.23.0(4)


where can I get it?

Possibly from the IDE Library manager… depending on how you originally installed it

From within the the library files themselves (OK, not as easy)

When using Blynk print, it will show in the serial monitor.

And you can even print it to a display widget with this command… Blynk.virtualWrite(vPin, BLYNK_VERSION);

Also… what version of ESP Core for Arduino? This you should be able to see in the IDE Library manager.

But all that said… if you do not know, then they are both probably too old :stuck_out_tongue:
I recommend updating them both…

thanks for detailed guiding me!

As I wrote earlier Arduino IDE board version(it was 2.4.0) and now I set up 2.4.2

I will check other stuff shortly

Ahh… yes, I glanced over that, but was looking for the word ESP CORE :blush: :stuck_out_tongue:

added newest Library but it did not help