Connecting two MCU's over USB

Projects Networking, Protocols, and Devices
1

EDIT: I'm assuming this isn't working because i don't have a usb to serial adapter on the receiving end of the usb cable, grabbing a few of those to see if that helps.

Hi folks! I have an ESP32-s3 project that I want to interface with. I am building a testing platform for this project using an Arduino Mega 2560.

The ESP32-s3 is wired to a usb-c port and is what i use to program the device and observe the serial output.

I've been trying to connect a USB-c (also tried with a USB-A) breakout to my arduino mega and ingest the serial data from the ESP32-s3.

I'm also using PulseView and a Logic Analyzer to verify.

Here is the schematic for the USB-C port that is connected to the ESP32-S3

image
image700×1024 38.1 KB

For the USB-A connector:
VBUS - 5v power supply
GND - Connected to both the logic analyzer and the power supply ground.
D+/D- connected to channels 0 and 1 on the logic analyzer.

When I hook up the USB-A breakout to the USB-C of the device, I use a USB-C to A cable that I know carries data because I've programmed the ESP32-S3 off the same cable. However, I get no signal on the logic analyzer of any kind.

Even if i get garbage, i would expect there to be some signal coming through on the logic analyzer but no luck.

Any guidance would be super helpful!

2

Hi @cyonic.

This won't work. It would only be possible with a board that had USB host capability (which the Mega does not), and even then it would not make any sense to do that as it would introduce a great amount of unnecessary complexity.

You should instead make a connection between the appropriate hardware serial transmit pin on the ESP32-S3, and the "RX1" pin on the Mega board.

You will need to adjust the code of the program that runs on the ESP32-S3 so that it sends serial data via the object associated with the transmit pin on the board you are using.

You can read the data that is transmitted from the ESP32-S3 from the program running on the Mega via the Serial1.

3

Thank you so much for the response. I guess it's time to figure out a different solution.

4

You are welcome. I'm glad if I was able to be of assistance.

Regards, Per