Introduction: Send Temperature & Humidity to Blynk App (Wemos D1 Mini Pro).
This Instructable looks at using the Wemos D1 Mini Pro to send datta (Temperature & Humidity) to the Blynk APP.
Step 1: Getting Started
We will get a temperature and humidity reading pushed to your Blynk App on your phone. Connect an LED as shown here: Note. I have used the blue DHT11 Digital Temperature/Humidity module which has three pins. The module is from Banggood. Other similar modules from different suppliers may have a different pin layout. Check this. The colours below are correct for the Banggood module:
Blue = Data signal (left)
Red = Vcc +5v (middle)
Black = Ground (right)
Step 2: Important.
As mentioned above.
Note. I used the blue DHT11 Digital Temperature/Humidity module from Banggood which has three pins. Other similar modules from different suppliers may have a different pin layout. Check this. The colours are correct for the Banggood module:
Blue = Data signal (left) Red = Vcc +5v (middle) Black = Ground (right)
Step 3: Getting Started With the Blynk App
Create a Blynk Account After you download the Blynk App, you’ll need to create a New Blynk account. This account is separate from the accounts used for the Blynk Forums, in case you already have one. We recommend using a real email address because it will simplify things later.
Why do I need to create an account?
An account is needed to save your projects and have access to them from multiple devices from anywhere. It’s also a security measure. You can always set up your own Private Blynk Server (Links to an external site.)Links to an external site. and have full control.
Step 4: Create a New Project
After you’ve successfully logged into your account, start by creating a new project.
Step 5: Name/Board/Connection
Give it a name and select the appropriate board (Wemos D1 Mini). Now click create.
Step 6: Authentication
Your Authentication token will be emailed to you and you will also be able to access it in the settings of your project. A new number will be generated for each project you create.
Step 7: Add Two Widgets (Value Display)
Your project canvas is empty, let’s add a two display widgets to show temperature and humidity. Tap anywhere on the canvas to open the widget box. All the available widgets are located here.
Step 8: Drag N Drop
Drag-n-Drop - Tap and hold the Widget to drag it to the new position.
Step 9: Humidity
Widget Settings - Each Widget has it’s own settings. Tap on the widget to get to them. Set them up with the following settings.
Step 10: Temperature
Widget Settings - Each Widget has it’s own settings. Tap on the widget to get to them. Set them up with the following settings.
Step 11: Run the Project.
Step 12: Run the Code.
Now let’s take a look at the example sketch for a Wemos D1 Mini Pro. Notice there are three key components that you will need to include:
1. char auth[] = ""; Specific to your project (Blynk App).
2. char ssid[] = ""; Specific to the network that we are connecting to (network name). You can "hotspot" from your phone also.
3. char pass[] = ""; Specific to the network we are connecting to (password).
CODE
#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[] = ""; // Your WiFi credentials. // Set password to "" for open networks. char ssid[] = ""; char pass[] = ""; #define DHTPIN D4 // What digital pin we're connected to #define DHTTYPE DHT11 // DHT 11<p>DHT dht(DHTPIN, DHTTYPE); BlynkTimer timer; float t; float h; void setup() { // Debug console Serial.begin(9600); Blynk.begin(auth, ssid, pass); dht.begin(); timer.setInterval(1000L, sendSensor); } void loop() { Blynk.run(); timer.run(); } // 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() { h = dht.readHumidity(); t = dht.readTemperature(); // or dht.readTemperature(true) for Fahrenheit // l = analogRead(LDR); 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); Blynk.virtualWrite(V6, t); }
Step 13: Display
Go back to the Blynk App and check your display. You should see the current temperature & humidity.
Step 14: Photo of Project
Step 15: Video of Project Working
Participated in the
Arduino Contest 2017