Library error when I run the code on Arduino IDE

Question

I've got the folllowing errors:

In file included from C:\Users\Lenovo\OneDrive\Documents\Arduino\libraries\Blynk\src/Blynk/BlynkApi.h:37:0, from C:\Users\Lenovo\OneDrive\Documents\Arduino\libraries\Blynk\src/BlynkApiArduino.h:14, from C:\Users\Lenovo\OneDrive\Documents\Arduino\libraries\Blynk\src/BlynkSimpleEsp8266.h:24, from C:\Users\Lenovo\OneDrive\Desktop\sketch_mar31a\sketch_mar31a.ino:36: C:\Users\Lenovo\OneDrive\Documents\Arduino\libraries\Blynk\src/Blynk/BlynkTimer.h:36:21: error: redefinition of 'class BlynkTimer' #define SimpleTimer BlynkTimer ^ C:\Users\Lenovo\OneDrive\Documents\Arduino\libraries\SimpleTimer-1.0.0/SimpleTimer.h:10:7: note: in expansion of macro 'SimpleTimer' class SimpleTimer { ^ C:\Users\Lenovo\OneDrive\Documents\Arduino\libraries\Blynk\src/Blynk/BlynkTimer.h:36:21: error: previous definition of 'class BlynkTimer' #define SimpleTimer BlynkTimer ^ C:\Users\Lenovo\OneDrive\Documents\Arduino\libraries\Blynk\src/Blynk/BlynkTimer.h:41:7: note: in expansion of macro 'SimpleTimer' class SimpleTimer { ^ exit status 1 Eroare de compilare pentru placa NodeMCU 1.0 (ESP-12E Module).

When I used this code:

#define BLYNK_PRINT Serial    // Comment this out to disable prints and save space
#include <SPI.h>
#include <ESP8266WiFi.h>
#include <BlynkSimpleEsp8266.h>
#include <SimpleTimer.h>
#include <DHT.h>


// You should get Auth Token in the Blynk App.
// Go to the Project Settings (nut icon).
char auth[] = "wwnCVJrGmlkVcYrYsCq-RjO2A0C5s16t"; //Enter the Auth code which was send by Blink

// Your WiFi credentials.
// Set password to "" for open networks.
char ssid[] = "DIGI-7v32";  //Enter your WIFI Name
char pass[] = "2UWCQ6R4";  //Enter your WIFI Password

#define DHTPIN 2          // Digital pin 4

// Uncomment whatever type you're using!
#define DHTTYPE DHT11     // DHT 11
//#define DHTTYPE DHT22   // DHT 22, AM2302, AM2321
//#define DHTTYPE DHT21   // DHT 21, AM2301

DHT dht(DHTPIN, DHTTYPE);
SimpleTimer timer;

// This function sends Arduino's up time every second to Virtual Pin (5).
// In the app, Widget's reading frequency should be set to PUSH. This means
// that you define how often to send data to Blynk App.
void sendSensor()
{
  float h = dht.readHumidity();
  float t = dht.readTemperature(); // or dht.readTemperature(true) for Fahrenheit

  if (isnan(h) || isnan(t)) {
    Serial.println("Failed to read from DHT sensor!");
    return;
  }
  // You can send any value at any time.
  // Please don't send more that 10 values per second.
  Blynk.virtualWrite(V5, h);  //V5 is for Humidity
  Blynk.virtualWrite(V6, t);  //V6 is for Temperature
}

void setup()
{
  Serial.begin(9600); // See the connection status in Serial Monitor
  Blynk.begin(auth, ssid, pass);

  dht.begin();

  // Setup a function to be called every second
  timer.setInterval(1000L, sendSensor);
}

void loop()
{
  Blynk.run(); // Initiates Blynk
  timer.run(); // Initiates SimpleTimer
}

Tead the error messages. It says you have duplicate definitions of something. If you aren't defining them in your code, that means your headers have a duplicate definition. Possibly `SimpleTimple.h` and `BlynkSimpleEsp8266.h`. — lurker, Apr 04 '21 at 13:53

score 0 · Answer 1 · answered Apr 26 '21 at 12:28

Blynk uses an open source SimpleTimer library.

There are quite a few libraries called SimpleTimer out there - See GitHub Search Results.

If you have a different version of the library to that used by Blynk you'll probably get a compile error:

BlynkTimer.h: 36:21: error: redefinition of 'class BlynkTimer

If you use the library that Blynk uses - marcelloromani/Arduino-SimpleTimer - you will not get errors on build, and can #include <SimpleTimer.h> and use it alongside Blynk without problem.

If you are using Blynk it is advisable to use BynkTimer instead of `SimpleTimer' for the following reason:

When BlynkTimer struggles to run multiple times (due to a blocked loop), it just skips all the missed intervals, and calls your function only once. New Blynk Library Release v0.5.3 - June 2018

To make the change to your code, remove

#include <SimpleTimer.h>

and replace

SimpleTimer timer;

with

BlynkTimer timer;

Library error when I run the code on Arduino IDE

1 Answers1