Module Relay OFF on start

[PeteKnight]

If you’re using a digital datastream to control the GPIO that your relay is attached to then this is one of the things that happens.
You can get around the issue easily by switching to Using virtual pins…

Using Virtual Pins to control physical devices

I thought I’d write a guide about how to use virtual pins with app widgets such as buttons, to control physical devices such as relays, LEDs etc… Why use virtual pins anyway? I’d always recommend using virtual pins over physical pins when developing your code. There are a number of reasons, but here are what I consider to be the main ones: Virtual pins are hardware independent. This means that it’s far easier to port your code from one hardware platform to another in future (when you realise…

If you’re already using virtual pins then the pinMode and virtualWrite solution described above is what you should do.

Also, it depends on your hardware. If you’re using an Uno for example the pin 13 always seems to do odd stuff on startup.

Pete.