ESP32 Forum

Hello !
I'm having some difficulties trying to get the ESP32-S3-WROOM-1-N16R2 to connect to usb, on a custom made board
I have read the following guide:
https://docs.espressif.com/projects/esp ... s/dfu.html#

When i connect the esp via usb cable the device just connects and disconnects,
when i hold down IO0 and pulse reset, the connection is made but i get the follwing error in device manager: i try to connect it with linux(debian) i get the following: I have tried to pull IO09 to gnd, with no success, also i had some debouncing capasitor on reset switch and IO0, i have tried to remove them, also tried to remove the decoupling capacitors on USB_DP+ and USB_DN-
I've measured that there is connection to usb pins and IO19 and IO20
And there is no shorts to gnd, but what's strange is that i measure around 3V on USB_DP+ but i dont measure any voltages on USB_DP-
voltages are OK, tried with external power source and USB powered

Please see attached schematic:

C7 and C9 should indeed not be installed. Aside from that, I don't really see an issue with your schematic... perhaps it's worth reading out the U0TXD pin to see what the bootup chatter looks like?

When not in download mode i get: While in download mode i get Still nothing happening on the USB port... when i try to connect to it. I dont have any way to debug the data on the USB bus.
Is there some special mode i need to initialize to use USB? i read about burning efuses but is this necessary?

That is 'proper' download mode indeed; unless you messed with its eFuses the ESP32S3 is more-or-less guaranteed to be a valid USB device at that point. That imo means that your issue is likely on the hardware side of things.

(Note you do need to burn eFuses to get DFU working, but if you do not do that you should see the internal USB-serial-JTAG device pop up as an USB serial port, and you're not seeing that, so better to debug that first.)

Just to check: when you plug the device into a Linux system, the kernel recognizes it as a *full*-speed device, not a *low*-speed one, right?

When i connect to linux, i only see the messages that i posted earlier, the device wont recognize. do you have any knowledge about needing pullup resistors on the usb data lines for the host computer to recognize it?

You tend to see more than that. Specifically, a message like: which indicates if the device is detected as low- or full speed.

You don't need to add external pullups/pulldowns: the ESP32 has an internal one and the fact that your PC detects insertion of an USB device at all indicates that works.

Why in your circuit not present 40 MHz resonator ?
As I see in DS:
"ESP32-S3 is unable to operate without an external main crystal clock."

Mihalich wrote: ↑

Tue Nov 22, 2022 7:41 am

Why in your circuit not present 40 MHz resonator ?
As I see in DS:
"ESP32-S3 is unable to operate without an external main crystal clock."

Because OP is using a Wroom module, which has the crystal (and flash etc) already integrated.

ESP_Sprite, how can author use two CAN if ESP32 only has one TWI module?

1 × TWAI® controller, compatible with ISO11898-1 (CAN Specification 2.0)

Dunno. Possibly they switch the TWAI peripheral between GPIOs or something, but it's offtopic; that's not the question they asked. I'm also not sure why you're looking at me to answer questions on OPs design; it's not like I made it.