Maybe it is obvious, but I have some (for me) strange issue. I have wemos D1 mini and 4 relay board.
By default relays are turned on and when pressing the button they switch off. I have solved this by exchanging low and high in virtual pin code, but the problem is that when power goes off and then back on, everything is turned on untill I manually switch status.
And another question. I would like to see in my app the real status of each relay (no matter how it appears in button widget).
You don’t need virtual pins for that anymore.
http://docs.blynk.cc/#blynk-main-operations-state-syncing-for-app
I know I can do this now direclty in widget settings, but it still does not solve the issue (but it is great to have this possibitlity btw).
Thanks for link, I will try option via widget with polling.
Can you send some snaps of realy board??
Why you not use NO (normally open) on relay board?!
For most Chinese Relays-Bords: relays is activated by pulling the logic level to low, it means if you don’t set those pins to high after wemos power-up, relays are active.
@monaco this is a good overview - http://arduino-info.wikispaces.com/ArduinoPower
Be careful as they trigger on LOW therefore the need to pull pins low immediately on SETUP() otherwise a reset of your microcontroller board could inadvertently turn relay on !
Personally I use relays that are ACTIVE HIGH because I don’t want my relays to turn on in case my microcontroller freezes etc. e.g. like the Sainsmart relays that can do AC/DC but for AC I stick to the solid-state, more pricey but rock-solid.