Questions about ESP8266 16-way relay board using 2x 74HC595 controllers

[PeteKnight]

I’ve moved your questions to a new topic, as I don’t want them cluttering-up the original topic.

Your question is answered in my original tutorial…

@PeteKnight

Creating the Blynk Template and Datastreams

To use the example code below, you will need to create a template in the Blynk web dashboard and add 18 virtual datastreams using virtual pins 0-17 inclusive.
All datastreams are virtual, and have a data type of Integer with a Min value of 0 and a Max value of 1.
I gave the datastreams attached to virtual pins 0-15 the name “Relay 0” to “Relay 15”
The datastream attached to virtual pin 16 is called “All Relays ON” and the one attached to pin V17 is called “All Relays OFF”.
The names you use don’t really matter, but it is important to use the virtual pin numbers I’ve specified above.

Pete.