Hi, I'm new to electronics and today I came across a problem. I am working on a project where an ESP8266 downloads data from an API, sends a response to a Arduino UNO clone which than turns on/off a relay. Very simple. Now, it worked fine till, suddenly, the Arduino turned off. Now, when I plug it in, the ON and L led flash and everything turns black? The PC doesn't recognise it as COM anymore. Whats the matter? Anyone?
Show a schematic how everything is connected. This includes all power connections and grounds.
Are you using a relay or a relay board? Link to the relay board can be useful as well.
I'm using a single relay board, dont know where its from, worked fine untill now.The schematic was very simple, just a pin from the ESP connected and used as an input, with a pull down resistor(idk what that means or if its mandatory). A second pin was used as an output for the relay. The arduino only turned on the relay if the input was HIGH. That simple. And it burned down. The arduino is not working on its own anymore.
You didn't fully answer sterretje's question:
This includes all power connections and grounds.
Also, this is not very clear:
gggiii:
I'm using a single relay board, dont know where its from
If you can't provide more information on this "single relay board" then please post a clear photograph of it. This is important because connecting a relay directly to an Arduino will destroy the Arduino. For this reason, it's common to use relay modules that have extra circuitry to allow an Arduino board's IO pin to drive the relay without harm.
If you want an answer to your question, you need to provide us with enough information; otherwise you're just wasting time here. Or you can figure out what happened on your own. The choice is yours.
Disconnect everything and load the blink program and see if that works .
Then go in steps from there , see if you can light an led instead of the relay .
Suspect you have a wiring problem or are driving the relay from the Arduino power supply...