How i can setting up usb(TL-WR841N_v8)

I soldered the usb to the tl-wr841n processor, but I do not know if there is a contact in openwrt and I do not know how to check it and how to mount it in openwrt USB, help.

Help me, please.

First you need the ehci driver. It is usually included in builds for models that don't have USB pinned out. There should be boot log messages like these:

[    4.888101] usbcore: registered new interface driver usbfs
[    4.893747] usbcore: registered new interface driver hub
[    4.899157] usbcore: registered new device driver usb
[    4.910252] ehci_hcd: USB 2.0 'Enhanced' Host Controller (EHCI) Driver
[    4.918734] ehci-platform: EHCI generic platform driver
[    4.924114] ehci-platform ehci-platform: EHCI Host Controller
[    4.929890] ehci-platform ehci-platform: new USB bus registered, assigned bus number 1
[    4.937932] ehci-platform ehci-platform: irq 3, io mem 0x1b000000
[    4.972045] ehci-platform ehci-platform: USB 2.0 started, EHCI 1.00

When you plug in a USB device e.g. a flash drive or a mouse, it should log a message like this:

[   366.085559] usb 1-1: new high-speed USB device number 2 using ehci-platform

This means that the USB hardware is working and a device has been detected on the bus, but it will not actually access the device without a device-specific kmod such as kmod-usb-storage. These are not installed in builds by default.

As the WR841v8 has only 4 MB flash there is very little space to install any extra packages. To get external storage working you'll probably need to make a custom ROM with some things removed.

Hooray, at least someone. I forgot to mention, I replaced the memory chip with 16MB, and put all the packages when building the firmware. The only thing I haven't figured out is what commands I need to view all the information you've written . Could you write me these commands again, please

It's the kernel log, which you can see with dmesg or logread.

Okay, so what you're saying is, if I have the usb soldered normally and there's a contact, I'll see the output like in the first case? And when I connect the flash drive, I will see whether or not the second output, which can be used to determine whether the data contacts are soldered or not.

The first group is the EHCI driver starting up, which will happen whether or not anything is connected to the hardware.

If you don't see that, you need to install kmod-usb2 etc.

The new device line happens as the EHCI driver finds a USB device connected to the bus.