Create a new Blynk project

Would you rather watch than read? Here's the video version of this article.

Let's continue where we left off in the previous article, where you created a Blynk account after installing the Blynk app on your phone, and you logged in for the first time.

In your case, you are probably greeted with just a blank screen that would look as in the picture below. This screen allows you to create a new project.

In my case, the app presents me with two existing projects that I had created earlier. I can browse through them and pick the application that I'd like to play with now.

Below is the application that I demonstrated in this guide's second article. I will delete it by going into the settings so that I can start from scratch.

One more thing that I wish to demonstrate in this article before we get into the app development step is the "i" button. This is the "information" button.

The information button takes you to the info screen which lists useful information. The information includes the identity of the Blynk server that the app is connected to.

Notice that the server to which I am connected in this example is the Blynk Cloud server.

Create a new Blynk project

Next, I will return to the blank screen to create a new project that I will call "demo 1" (for lack of a more imaginative name) and select the device.

We have access to a wide range of possible devices; however, there is no mention of the Arduino Nano 33 IoT.

Let's see if we can select a similar device.

The Arduino MKR1000 is the closest available to the Arduino Nano 33 IoT, so I will select that. It's important to choose a device that is as close as possible to your actual target device because that is how Blynk knows which particular pins to provide to you in its user interface.

I'm going to come back to that shortly.

For the connection type, choose WiFi.

Next, tap on "Create Project". The app will email you the application token.

This token is important.

Think of it as a password that allows my Arduino app (the sketch running on the Arduino) to talk to your Blynk application on your phone via the Blynk Cloud server. Allow a minute or so, and check your inbox for an e-mail from Blynk.

Tap the "OK" button.

If you can't find the token e-mail or you want it to be sent again, or for whatever reason, you made a mistake somewhere, and you want to recreate that token, go back into the settings.

Here you'll see the authentication token that was generated looking like the one in the picture below. You can change the token by tapping "Refresh," or you can tap "E-Mail" to send this large alphanumeric token to your e-mail address.

That does not mean that you cannot address all of the pins on your Arduino just because the MKR1000 device gives us 14.

Remember the virtual pins?

The Blynk app provides you with dozens of virtual pins. I have written a detailed guide about virtual pins, where I also demonstrate how to use them.

For now, just know that you can map virtual pins to any functionality you wish. That may be a pin, or a custom function. Anything at all.

Therefore, you can tap onto any functionality you wish to through the abundant virtual pins rather than digital or analog pins.

I will now delete the "OFF" button so that we can do the development later on, and I will go over to the Arduino sketch on my computer.

I start with a blank sketch.

The easiest way to begin is to use templates and then modify them as needed.

There are two sources of templates that are managed by the Blynk developers. The first one is called the examples.blynk.cc or the Blynk example browser that you can see in the picture below.

This website gives you access to many valid combinations of boards and the connection type that they're using.

For example, if you're using an Arduino Uno with your Blynk application and you plug in an Ethernet Shield W5100, then website will give you a template that you can use and build on.

You can do the same thing with the ESP32, for example, and the built-in WiFi. So, we've got the ESP32 built-in WiFi template. 

If you go for an Arduino Zero (not the 033, just an Arduino Zero), it's got other options. Here's the template for the Arduino Zero + Wifi Shield 101.

If you haven't done so already, check your inbox for the email with the authentication token for your project.

So, copy the token and paste it inside your sketch file, insert the authentication character array like this.

With that done, go ahead and upload the sketch to the Arduino. 

If you get a warning that WiFiNINA.h is missing you will need to install the missing library.

Go to Sketch --> Include Library --> Manage Libraries... and install the WiFiNINA Library.

Upload the sketch and test

Try again to compile and upload the sketch.

Let's do a little experiment.

Add a button widget to your Blynk project.

Tap on the button to see its configuration, and select the built-in digital pin 13. Press OK (top right corner of the screen) to commit your changes.

Press the play button on the top of the screen.

And finally press on the round button widget (and hold). You can see that the built-in LED on pin 13 turns on and off. 

Perfect.

Next, let's also control the external LED.

Stop the application, and tap anywhere on the screen where you want to insert a second button widget.

This time choose the Styled Button widget, and tap on it to configure it.

The LED on my breadboard is connected to digital pin 2. So, I will choose digital pin 2 (D2) in my Blynk project. I will change the button type to a switch so that it stays pressed when I tap it.

Now, play the app again and tap on the big button.

You can see that the external LED turns on, and it stays on and the same thing when I turn it off.

Conclusion

As you can see out of the box, the Blynk library allows me to control pins and turn them on and off.

But if we want to do anything more interesting, like work with sensors, for example, or write PWM values to the pins, we will actually need to write a little bit of code.

In the next article, I will show you how to do something very simple, such as to control the external LED via PWM.

This will allow us to work with virtual pins as well.