I'm currently programming a Nodemcu ESP8266 board, fully compatible with Arduino IDE. The project drive a relay board with a GPIO pin set as output.
You can see the board pinout in the following image:
Unfortunately, at boot the pin goes LOW for say a millisecond. It is something related to bootloader, as the pin goes HIGH as soon setup() is executed.
The final result is that the relay is triggered for a very short time every time the board reboots.
I really would like to get rid of this short signal. Is there some simple circuit I can realize to ignore every signal shorter than a few millisec?
The pin goes from a LOW value (0v) to a HIGH value (3,3v). The relay board should trigger the relay for any signal > 1,5v.
If I use another pin the problem is not present. Thus I think the connection (quite simple actually) is correct and no problem with the software. Unfortunately I should use D8 in the final setup.