Wio Link + Grove Temperature & Humidity failed read sensor

Hi All

I’m using my wio link + grove temp humidity and blynk, following post WIO Link with Blynk and Blynk with Seeed Wio Link? and this Blynk + wio link

My sketch is:
Download latest Blynk library here:

  Blynk is a platform with iOS and Android apps to control
  Arduino, Raspberry Pi and the likes over the Internet.
  You can easily build graphic interfaces for all your
  projects by simply dragging and dropping widgets.

    Downloads, docs, tutorials: http://www.blynk.cc
    Sketch generator:           http://examples.blynk.cc
    Blynk community:            http://community.blynk.cc
    Follow us:                  http://www.fb.com/blynkapp

  Blynk library is licensed under MIT license
  This example code is in public domain.


  This example shows how value can be pushed from Arduino to
  the Blynk App.

  For this example you'll need Adafruit DHT sensor libraries:

  App project setup:
    Value Display widget attached to V5
    Value Display widget attached to V6

/* Comment this out to disable prints and save space */
#define BLYNK_PRINT Serial

#include <ESP8266WiFi.h>
#include <BlynkSimpleEsp8266.h>
#include <DHT.h>

// You should get Auth Token in the Blynk App.
// Go to the Project Settings (nut icon).
char auth[] = "78692b97ec314bxxxxxxxxxxxxxxxx";

// Your WiFi credentials.
// Set password to "" for open networks.
char ssid[] = "Encona AP4";
char pass[] = "3112159010";

#define DHTPIN 14          // What digital pin we're connected to

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

BlynkTimer 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!");
  // You can send any value at any time.
  // Please don't send more that 10 values per second.
  Blynk.virtualWrite(V5, h);
  Blynk.virtualWrite(V6, t);

void setup()
  // Debug console

  Blynk.begin(auth, ssid, pass, "", 8442);
  // You can also specify server:
  //Blynk.begin(auth, ssid, pass, "blynk-cloud.com", 8442);
  //Blynk.begin(auth, ssid, pass, IPAddress(192,168,1,100), 8442);


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

void loop()

And result in my console :
Failed to read from DHT sensor!
Failed to read from DHT sensor!
Failed to read from DHT sensor!
Failed to read from DHT sensor!

Thanks in advance!

@mustofa908 have you tested the Wio and Grove with the DHTtester sketch i.e. without Blynk?

Which port are you connecting the sensor to on the Wio?

In the 3rd “Community” link you listed I referred to MOSFET gated to GPIO 15 for “power” but take care with this and check with a multimeter.

Hi Costas
Thanks for your respons, I’ve tried using DHT sketch tester, but the result is same.[quote=“Costas, post:2, topic:14531”]
Which port are you connecting the sensor to on the Wio?

I am using digitalport 0 for this.

Can you give me a proper reference for this, as I am a newbie for development board.

To add the GPIO line where exactly should be added?

pinMode(15, OUTPUT);
digitalWrite(15, 1);

Sorry if the question is very basic. Thanks in advance!

I don’t want to destroy your MCU or sensor.

Do you have a multimeter?

yes i have

@mustofa908 remove the sensor for now.

Add the following lines as the first lines in setup()

pinMode(15, OUTPUT);
digitalWrite(15, 1); 

Check you have power to the data pins with your meter and if you do then try with the sensor in place.

Take care.

1 Like

@Costas Thank you for the help, this work now :+1: