Repurposing is also great. I have FTDI UART adapters that I've used once five years ago, and couldn't find them later, then had to buy another new one for using it (again) just once.

If I can take one of my rp2040s and use it for half and hour and then use it for a different thing, it's great

RP2040 is so cheap it is used in the debugger for the Pi Pico.

https://www.raspberrypi.com/documentation/microcontrollers/d...

WCH CH340 USB-UARTs cost less than an RP2040 (and probably the external flash.)

https://www.lcsc.com/search?q=CH340

The reason to use an RP2040 is that you need a little bit of logic with that UART.

Doesn't the RP2040 require external qspi flash? What does that cost?

MCP2200 is ~$2.50 in single units and you don't have to deal with firmware or programming.

There's other FTDI chips than the FT232, the FT230 can be found for <$2.