Map Arduino Nano ESP32-S3 pins to GPIO 19 and 20

Official Hardware Nano Family Nano ESP32
1

It appears that the Arduino version of the ESP32-S3 has no pins that map to Expressif's GPIO pins 19 and 20. Is this correct? Is there no way to use this board as a USB Host? Thanks, Aaron

2

It looks like they might be exposed via the pads on the underside so a bit of soldering would be required, although it seems they are also routed to the USB-C connector.

See the full pinout PDF.

3

Why can't you use different pins?

4

Thanks for the comments

BitSeeker:

"might be exposed via the pads on the underside"

I had previously look at this. None of the pads are mapped to GPIO 19 or 20.

sonofcy Karma: 2000+

"Why can't you use different pins?"

According to Expressif's schematic GPIO's 19 & 20 are hardwired to the USB>UART OTG unit. The DEV versions have a 2nd C socket for hosting. The programmer C socket's USB>UART is a separate chip.

5

Since a USB Host has to supply power back to the client device it might be easier for you to use a USB C breakout to get GPIO 19, 20 and the supply power correctly for your client. You would power the Nano normally and power your client with its own supply.

6

Thanks for your suggestions. I'm already using a breakout board and separate power supply to the KB. The question is how to connect D+/D- to an Arduino NANO ESP32-S3 board that doesn't seem to map GPIO 19 & 20 to any of its pins.

7

Oh, I see. As you suspected, the NANO ESP32-S3 board only maps its GPIO 19 & 20 pins to the USB C connector. This give you at least two ways to connect. One is to solder wires to the traces that go to the GPIO 19 & 20 pins. Another is to use a USB C breakout board plugged into the USB C connector on the NANO ESP32-S3 board to pick up the signals. Whichever way you choose power the NANO ESP32-S3 board through Vin and use an independently regulated, current-limited 5V supply for the USB device's VBUS with just the grounds common.

8

Search for "usb otg type c male to type a female cable or adapter". This kind of cable is the same cable or adapter used to connect a USB keyboard to a MacBook USB type c port. Also the same cable to connect a USB keyboard to a phone with USB type C port. I use this type of cable on a Uno R4 Minima to experiment with USB host.