ESP8266 Community Forum

I have a feature in my project that if you pull pin 5 to ground (button) the NodeMCU will clear saved wifi settings and start a hotspot to enter wifi creds. This works as like I expect.

I wired a 12v 2a power supply to the NodeMCU and then plugged the power supply into a surge protector strip. There is a small fan on the strip too and I've noticed that the NodeMCU will start the reset function when the fan is turning on or off.

But it doesn't trip the NodeMCU every time though. It sometimes takes 2 times turning the fan on and off to trigger it, sometimes one. I've plugged another project into the same strip, wired differently and with 9v 1.5a VIN also has the wifi manager code, and the two nodes don't always trip at the same time.

What is going on?

I would say the fan is either causing a brownouts, or a spike on the power of Emi, try a stronger pull-up on reset, maybe a large capacitor 1000 uf near vdd.

RichardS

That's a good idea. I put a 10K resistor on see what happens.

I put a 10k resistor on but it's still flipping. I then directly connected D5 and the 3v pin and it still flipped then too.

I guess I'll be putting a cap on. Something like this?
https://www.amazon.com/McIgIcM-1000uf-capacitor-Aluminum-electrolytic/dp/B06WGPNM19

So I just put a cap before VIN?