UART Communication - I need four Uarts in Jetson

Hello, I am working with Jetson Nano in a biomimetic underwater vehicle. And I have some issues. I need four Uarts comunications in Jetson Nano for received the sensores info.

If not possible to change the Expansion Header 40 Pins GPIO what device I shoud use?

GPIO do not normally work as a UART, although you could custom program their function. Speed simplicity would probably be “unsatisfactory”. Probably the best solution would be to add a multi-port USB serial UART. If you use a USB serial UART with the FTDI chipset, then it should just work without complication.

What usb serial UART Device you recommend? I need four UARTS

Any UART with USB to plug into the Nano, and with specs compatible with the device you are communicating with is good. What voltage level does your device use, e.g., 3.3V? 1.8V? 5V?

As examples, there are a lot of cables here which are FTDI, but differ in voltage and connector options (e.g., loose/bare wires, 6-pin, individual wires with pins, so on):
(note that you only need RS-232, the more expensive RS-485 are not likely to do what you want unless your devices support RS-485, and most do not)

Notice that some are 3-wire, which is ground and TX/RX. Others are 6-wire, and this adds CTS/RTS flow control (there is also a power related wire, but normally you wouldn’t use this). If you don’t need CTS/RTS the 3-wire would be a better choice, but 6-wire still works.

The problem I tend to see with multi-port adapters is that they want to use a DB-9 connector, and I assume your devices do not use this unless it is something old. I am guessing that using a USB HUB and four individual USB-to-serial adapters is not what you want to do, but that would be a simple solution, and if the HUB is externally powered, then you could remove its power consumption from what the Nano uses (this would be more stable).

I doubt you want to build your own board, but I’ll throw the idea out there anyway: FTDI chips are available where you could put your own USB HUB chip and four FTDI serial USB UART chips on a board and get exactly what you want, e.g.:

Possibly there are some m.2 boards out there, but the ones I am aware of use the higher voltage/larger connector DB-9 connector.

Thank you a lot for help me in this issue.
I am developing a small biomimetic underwater vehicle, and for there reason I need that the device that I choose be a small one.
With your advice I research some devices. What you think about this:

This is probably a good choice, but because the UART offers some extra features I won’t guarantee that the stock driver by itself is enough. It may be that some features require other software, but the chip may default to UART anyway, and if you don’t require those extra features (e.g., emulating SPI or I2C), then it may not matter. I do see the spec sheet here, and it seems like a good place to start:

NOTE: I also do not know if it runs at the voltage levels you require.

Thank you. You save me ;)
The voltage that I need it’s 3.3V, it’s for a AHRS VN100, ublox GPS NEO 7M, echosounder from bluerobotics and module GSM SIm 800L.