Using serial with M1 MacBook Air

I am having trouble detecting the HiFive Unmatched using sudo screen on the M1 MacBook Air, which means I cannot use serial connection. This problem also extends to PuTTY and a Linux PC that I have. Sometimes it does not detect anything on ttys0, or sometimes no output comes out from the port. Does anyone know how to set up a serial connection on these devices?

On macOS you should have two /dev/tty.usbserial-* devices, numbered consecutively; ttyS0 etc is Linux’s naming convention. But if you’re seeing it on different hardware with a different OS that sounds like a hardware issue with the board and nothing to do with using a MacBook (which I’ve had no issue with and is what I use).

Be sure to check both ttys0 and ttys1. I’ve seen the console appear on different ttys on different machines. I don’t know why this happens.

I have a pc purchased last year with an Asus motherboard that I’ve never gotten to work with my Unmatched, but my 6 year old Lenovo laptop works just fine. Both running the same version of linux. So try multiple machines, including older ones, if you can.

I don’t use MacOS so I can’t help with that. On Linux it should just work automatically.

Update: It is a hardware problem. It seems to work better now. Thanks!