Hands-On Internet of Things with Blynk

Using virtual pins

If you want to further process the values coming from the Slider widget, virtual pins are your best friends:

1. First, go to edit mode by tapping the stop icon on the toolbar.
2. Tap GP18 under OUTPUT. Choose Virtual from the left-hand side list and V1 from the right-hand side list (this is the only pin available on Raspberry Pi for PWM). Then, tap OK.
3. The maximum value for OUTPUT should be 1023.
4. Now, your Slider Settings page should look as follows:

Slider settings for working with Virtual Pi V1

5. Tap the back icon to go to the canvas.
6. Connect to your Raspberry Pi using PuTTY and open the main.cpp file using nano.
7. Modify the ...