We made a tiny coin size USB UART adapter using CP2104 chip and hope it works for you.
https://www.gl-inet.com/product/usb-uart-cp2104-adapter/
That’s pretty cool and I could probably 1 or 5 of these just hanging around. That’s a sweet price.
Tell me, are the TX/TX of the UART 3.3v or 5v? Makes a diff for Raspberry PI usage (5v will fry the GPIO).
it is 3.3V