Hello,
I made a thermometer with screen attached.
When powered with my laptop it works fine :
But when I use this adapter I get strange values:
Any idea why ?
Changing Value? What you mean by strange?
Maybe unstable power from plug? Try another.
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Maybe it is feeding 9V to your circuit? Try one, which only does 5V…
It gives correctly 20 degrees on my laptop, but above 85 degrees when connected on the adapter.
I just tested with 2 other adapters (one I constantly use with another same type ESP32), but it doesn’t work.
I measured the power on the temperature sensor and it gives 3,3 V.
When connected to my laptop I see this in the logs :
But when connecting to the adapter (I get a value “Unknown”) I get this :
I stil think this has to do with the DC of the power supply not being clean enough. There almost sure is too much noise.
The power supply’s do not filter nicely.
Maybe adding a capacitor would help…
Already tested with 5 adapters, without succes.
Do you have a link where I can buy these ?
Do you have any “brand” adapter (one you maybe received together with a phone or tablet) by chance you could try? There is so many dodgy usb adapters out there which can cause various problems (specially) with micro electronics. 
That’s the problem, they are all brand adapters (LG, Samsung and an old HTC).
That’s weird. Are you sure you didn’t “shake” the cables to hard when moving away from your pc usb outlet and their might be a half loose connection now? I would check the whole wiring again or maybe even just re do it - these dupont cables a prone to have loose connections from my experiences… 
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