Relay buzzing unless hooked after ESP8266 boots up.

[nardev]

I believe that it would be proper way to put the whole project description but i hope it might be enough for someone with experience.

So, very simple thing.

I power up ESP8266, it boots, everything works fine.

I hook one of those cheap songle relay module boards (i tried other relays too, same thing) and controlling the relay works perfectly. No issues there.

However, if i leave it like that and restart EPS (power down/up), the esp never boots up, and there is silent buzzing from the relay.

Probably this might be all you need:

Between the ESP IO pin and relay board i have 1K resistor, 2n3904 NPN transistor and it switches 5V relay powered from external 5V.


Any clues?

[nardev]

I believe that it would be proper way to put the whole project description but i hope it might be enough for someone with experience.

So, very simple thing.

I power up ESP8266, it boots, everything works fine.

I hook one of those cheap songle relay module boards (i tried other relays too, same thing) and controlling the relay works perfectly. No issues there.

However, if i leave it like that and restart EPS (power down/up), the esp never boots up, and there is silent buzzing from the relay.

Probably this might be all you need:

Between the ESP IO pin and relay board i have 1K resistor, 2n3904 NPN transistor and it switches 5V relay powered from external 5V.


Any clues?

 

Just as i wrote this, i realized.. why the hell do i have only 1K there lol.. doesn't buzz any more...

[ArthurDent]

See you got it working. Maybe you have already seen this but there is good information here for future reference.

https://www.forward.com.au/pfod/HomeAutomation/OnOffAddRelay/index.html#single5V

[nardev]

THnx

p.s. one of the issues was that MCU had pull-up on the pins i used my default.. so.. it even made more confusions..