Custom Board USB UART Pins ESP32-S3-Wroom1

[elyaso]

Dear,
I'm designing a board using ESP32-S3-Wroom1.
I'm confused regarding the USB Pins, in the datasheet it shows the IO19,IO20 are directly connected to USB ports.
Yet in all designs i see that a usb to ttl chip such as CP2102 is used.
I couldn't find clarification in the datasheet.

[elkadir]

GPIO 19 and 20 are directly usb otg pins. But still there is cp2102 is used because there are two usb ports (second one is to use debug port) and in most cases people are using usb protection chips that are blocking voltages more than 5,25v or for electro static discharge protection.
it is not good to use directly if there is possible esd.

u can use directly 19 and 20 for usb and probably u will not need to use debug port (Jtag usb or second usb which is used for debugging)

[ESP_Sprite]

Yep, reason to do it in devkits is that you may want to use the USB port for other purposes (e.g. hook up an USB stick to it). If you do your own design and have no reason to want to do that, feel free to leave the CP2102 out.

[elyaso]

Thanks for the replies, very clear.

[e-music]

I have the same situation and I would like to confirm it before designing my own board. So, a USB<>UART bridge chip is not necessary to program/debug ESP32-S3-WROOM modules? So, IO19/IO20 are directly available as OTG USB? And what about VBUS? IT seems ESP32-S3 doesn't implement VBUS sensing.

[orbitcoms]

I uploaded a separate post in this forum and did not get a response yet but see my question is very similar to this.
Would someone please advise the minimal pin set up on ESP32-S3 to debug and use JTAG feauture. ie. Say JTAG and flash chip via pins 19/20 and use TX0 for monitor? I expect to also need to use ENABLE and make sure the strpping pins are in correct state during boot?

Thanks

[e-music]

I have pretty much the same problem, and I have been waiting for a reply for so long and still nothing yet. I'm designing a custom board, I referred to datasheet and reference manual, but couldn't find much about the pinouts of the ESP32-S3. Although the ESP32 is very popular, it is still surrounded with a lot of ambiguity on many aspects of its development cycle.

[orbitcoms]

From what I have read in the datasheet is looks like a single USB port has 2 channels and can be used for both debugging and programming. If this is the cas I assume I can just use the USB port and have the TX0 as monitor output?

[ESP_Sprite]

From what I have read in the datasheet is looks like a single USB port has 2 channels and can be used for both debugging and programming.

More or less; programming generally uses the serial port, debugging (depending on if you debug using log messages or full-on JTAG style debugging) can use the serial or the JTAG port.

[/quote]
If this is the cas I assume I can just use the USB port and have the TX0 as monitor output?

You can set the USB-serial-JTAG as the primary console, and if you do UART0 would be free to use for other things. Do note that there will be some startup chatter on TX0, though.