ESP32 Forum

I have seen boards like T7S3 that do not have usb chips. How do they work? Is it implemented in the esp32-S3-wroom-1-n16r8 module? if so, does the module come programmed ready to be used with a usb connector? if not, what is the procedure for making usb connectivity. Also, how does one identfy the modules that do not need external chips? Hope I am at the right place for the question.

The ESP32S3 has built-in USB and you can use that to program/debug the chip. The details are in the datasheet/TRM, but thispage has the important bits.

Thank you ESP-Sprite. That was very useful.

which of the esp32 modules come with built-in USB. Is there a quick way to identify them?

Check the datasheet of the chip and module. The chip datasheet will tell you if the chip has USB capabilities. (At this point in time, the ESP32-S3, -C3, -C6, -H, -P4 have USB-JTAG-serial, the -S3 and -S2 have USB-OTG) and the pins the USB signals are on. The module datasheet will tell you if these pins are available. (Generally, they will be available unless you get very specialized low-GPIO modules.)

I'm working with an ESP32-C3 module (just the module) and dutifully wired up the D-/D+/GND to my PC and it does not recognize anything meaningful. It see's *something* and enumerates it as an "Unknown USB Device (Device Descriptor Request Failed)" but that's it.

I can flash code to it as normal over the TX/RX but the "build itn USB" seems to elude me. I have tried looking for drivers to no avail. Anything obvious and common I am doing wrong?

Did you possibly swap the D+ and D- leads?

I am embarrassed to admit that I did swap them. The silly thing is of course I tried them both ways and somehow came to the conclusion it did not work in either configuration. I assume some other problem prevented me from seeing it work with the correct polarity.

Once I discovered that everything started working as expected, marvelous little module here.