How do I connect Arduino nano with QinHeng Electronics HL-340 USB Serial Adaptor to OpenWrt?

Question

When I connect the USB interface from my arduino nano to my openwrt router then the command lsusb shows:

Bus 001 Device 003: ID 1a86:7523 QinHeng Electronics HL-340 USB-Serial adapter

But I do not get a new serial device in /dev/tty*

I have kmod-usb-serial installed.

Answer 1

Posting this in case it is useful to others. The answer turns out to be that I needed the kmod-usb-serial-ch341 kernel package:

opkg install kmod-usb-serial-ch341

The HL-340 is a CH 340 compatible device.

Once the ch341 driver is installed the nano appears as /dev/ttyUSB0 and defaults to 115200 baud. From dmesg

[   20.000000] usbcore: registered new interface driver ch341
[   20.000000] usbserial: USB Serial support registered for ch341-uart
[   20.010000] ch341 1-1.2:1.0: ch341-uart converter detected
[   20.040000] usb 1-1.2: ch341-uart converter now attached to ttyUSB0