Did I almost kill my laptop with an ESP32?

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Paul_Alexa

Joined Jul 16, 2022
22
Hello and thank you for reading this.
To cut a long story short I made myself a panel for a linear PSU that displays current, voltage and other info, using an ESP32, ADS1115 and an ST7735 display. I was programming the ESP which was connected to the power supply as per the schematic attached. The power supply itself had no load connected and it was not plugged in.
I also took the precaution of unplugging the 5 volt power supply that powers the all of the panel electronics. I made sure there was no way I could fry my laptop. Well, after uploading the code it crashed two of my usb ports. One of them still worked. The error was "port reset failed" After upgrading to Windows 11 ( I suspected my laptop had some driver compatibility issues) and deleting the usb hub driver plus restarting the laptop they all came back.
Now, I also failed to use the proper button sequence for programming the ESP. Was it that which crashed my ports or some
sort of transient effect?What could I do in the future? I looked for USB isolators but the cheaper ones are only able to supply 200 mA of current. Could I simply use a USB cable with a Schottky diode in series with the 5 volt line? I'm scared to even connect the thing to my laptop anymore. No shorts were detected.
Thanks for taking your time to help me.
Cdc9H.jpg
 

BobTPH

Joined Jun 5, 2013
8,665
Are you using a commercial ESP32 board, or one you designed?

You show 5V to the ESP32. I thought they were 3.3V devices.
 

geekoftheweek

Joined Oct 6, 2013
1,183
How is your power supply connected to the system? I ask because you are showing 5V off of the ESP32 and I have a feeling you have connected that to your power supply. If so that could be the cause of issues. You will want to connect all the grounds to a common point, but not the positive power connections. Technically you are not supposed to connect anything to your USB port in a way that it could power the host. I know in a laptop there is little chance of that, but if for some reason your power supply's voltage is higher than your laptop's USB voltage it could cause issues there. I know my laptop USB ports tend to run a bit under 5 V for some reason.

I have a feeling the reason your ports died until reboot was more of a protection than anything. A "port reset failed" would be a pretty big deal and would essentially mean that something is causing the data lines to not work as they should. The safest thing to do would be to disable the port(s) until reboot and see if everything works then. It may also just be that it was an unrecoverable error either due to the USB host controller design, or something that wasn't handled properly by Windows.
 

Thread Starter

Paul_Alexa

Joined Jul 16, 2022
22
Hello, I used the ESP32's internal regulator because I did not have a second 3.3 volt one on hand
I used a commercial board.
I doubt the votage was higher on the device since everything was unplugged.
Although not ideal, I might consider using a cheap usb hub as some sort of buffer. Thank you for your answers.
 

Thread Starter

Paul_Alexa

Joined Jul 16, 2022
22
This thread can be closed. I have found what the issue was and it was.... rather unexpected to say.
It was an earthing issue. I live in an area where water heaters are popular because the city's hot water system is inadequate. I found this when I got zapped by an earth wire..... One of the neighbours had a faulty water heater.
Thank you all for your help.
 

geekoftheweek

Joined Oct 6, 2013
1,183
Just out of curiosity where is it that you live where the city provides hot water? Around here water heaters are not just popular, they are the only means of hot water other than heating it on the stove.
 
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