WSL and serial port

Question

I am using Win10 and Linux Ubuntu on WSL 2.0.

For testing purposes of some programs, I would like to use the serial port of my PC in "loopback" with Linux running through WSL.

Basically I would like a process on Linux/WSL to be able to send/receive data from a Windows process or vice versa, through serial port, but without any hardware hack.

Of course I have already tried to set the Windows process serial as "COM1" (as indicated by the Windows resource manager) and the Linux port on WSL as "/dev/ttyS1", but apparently it doesn't work.

Is there any way to do this?

If WSL does have the necessary support, then you would need to use two ports, and not just one in somekind of "loopback". Having two processes reading and writing to a single port does not make much sense, so having two operating systems also own/control a single port is impractical. — sawdust

kunif kunif · Accepted Answer · 2021-10-03T23:07:28

WSL 2.0 does not support serial ports.

Exceptions for using WSL 1 rather than WSL 2

WSL 2 does not include support for accessing serial ports. Learn more in the FAQs or in WSL GitHub repo issue on serial support.

The following options are possible.

Revert to WSL 1.0 and use
Use third-party products
- For example, there seems to be something like this.
  Windows USB Server
  VirtualHere USB Server
  Although it is a Japanese article, there is such a trial article.
  WSL2でUSBデバイスを認識させる

Also, if you want to communicate between serial ports even if WSL2 cannot recognize USB serial, this method is also available.
Connecting to serial port (com port) over network

And as you can see from the above explanation, if you want to communicate between the processes of each OS, you can simply use a TCP/IP socket instead of the above mechanism.

WSL and serial port

1 Answers