How to write/read different pins defined on the spiff?

[PeteKnight]

I think the only tool that will work for you is BLYNK_WRITE_DEFAULT()
This returns a parameter which tells you which virtual pin was the source of the BLYNK_WRITE command.

I used it in this example as a neat(ish) way to streamline my code.

Using the MCP23017 IO Expansion Board

EDIT NOVEMBER 2021… Anyone interested in controlling multiple relays may also want to take a look at this topic, which uses a pre-built 16-way relay board and 2x 74hc595 shift registers: END OF EDIT . I had a project recently where I wanted to use 5 physical buttons, with built-in LED indicators, to control 5 relays. That meant having 15 GPIOs available, so I built the project around an ESP32 dev board. I also needed a few more GPIO pins for other sensors, so by the time I was done I was o…

Pete.