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ESP32S2 USB not working

Posted: Mon Apr 07, 2025 6:55 pm
by Carter3DP
Hi all,

I have a custom board that just came in with an esp32s2 (esp32s2fh4) on board. I am trying to communicate through the on chip usb, with the usb connector running directly to the esp (D- on GPIO19 and D+ on GPIO20), but am getting Device Descriptor failed (error 43) if I plug directly into any port on any computer, and I get Port Reset failed if I plug through a hub. I get these errors no matter what, tried with 0 ohm jumpers in series, solder bridges, and with pullups on both D- and D+. I then looked at the data lines through an oscilloscope and noticed the D- line takes longer than it should when going back to the reference voltage at the end of any packet (compared with D+ line and another board I had laying around). Would this be an issue with pcbs design or a physical issue with the esp?

Another question about these chips: I got a batch of 5 boards, and all of the esp32-s2 have the same exact markings on the outside (ESP32-S2F, 112022, H2AP2Q494, UAQOPKV069 from top to bottom). Should these markings be all the same or should it be unique per chip? These were assembled by JLCPCB, but the chips were sourced through digikey on JLCPCB's website.

Oscilloscope on D+
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Oscilloscope on D-
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Board Design for USB
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Re: ESP32S2 USB not working

Posted: Tue Apr 08, 2025 1:32 am
by Sprite
Datasheet:
ESP32-S2 is unable to operate without an external crystal clock.
And I'd expect chips from the same batch to have the same markings, so I don't think that's an issue.

Re: ESP32S2 USB not working

Posted: Tue Apr 08, 2025 12:21 pm
by Carter3DP
And of course I missed that small note. Thanks for the help. I feel as though there should be another mention of this, as this is pretty important and it is the only line that says that in both datasheets.