Develop Reference

Pair computer and phone with USB cable once, and then always use ADB over WiFi, even after reboot

I'm using scrcpy to mirror the phone screen to computer, which uses adb.
I've followed the steps and it works:
# connect via USB
adb devices
adb tcpip 5555
# now unplug USB, and the following will work over WiFi
adb connect 192.168.1.14:5555
scrcpy
But when you reboot the phone or computer, doing adb connect 192.168.1.14:5555 and scrcpy doesn't work anymore (NB: the phone IP hasn't changed, it's fixed).
Reading the answers from Run/install/debug Android applications over Wi-Fi?, I see 3 options:
plug the USB cable each time before doing a wireless connection, but this is annoying, and somehow reduces the interest of wireless...
Use "ADB over network" (main answer's screenshot), but as noted by many people in comments: "i do not have the "ADB over network" option in debugging option"; so this option doesn't work for me
other techniques that need root (not possible for me)
Question: how to pair the phone and computer with a USB cable only once, and then be able to use adb between them without having to use a USB connection first, after each reboot?
Note: I don't use Android Studio, but only scrcpy.

It's not possible without root the phone. If your phone has rooted. You can use this app. https://play.google.com/store/apps/details?id=com.ttxapps.wifiadb&hl=en. With this app you can easily debugs android apps with only wifi. Don't want USB cable even only first time.

Based on all the information I have the next conclusion. Just for reference, how a low-level setup with changing add routes works inside, described here. It comes up, there is a pretty straight thing inside changing navigation with adb tcpip <port>.
The first thing we need to do, it's setup system property with tcp port with name setprop service.adb.tcp.port (and values with a port number) By default, there is not such property.
And then just restart adb with few commands. stop adbd and start adbd on a device in order to debug bridge listen new port. What is the trick here, that you don't have access to this service and stop/start it without root. But it could be easily done, via Developer setting with stop/start debugging.
This few simple action hidden inside adb tcpip <port>. And the problem, that you cannot change system properties (point 1). That is why all application requires root access, it's just to change the single option. That is why, we need to connect with USB to debug bridge, which can change properties with his sepolicy.
So answering your question. I don't understand either, what is the problem or enabling this small setup in Developer options. But right now, it's possible to do so on some Roms, or devices with root access.

adb can't find device after failing to connect through WiFi

Essentially, my problem is that I tried connecting my device to adb over Wifi, got to adb connect xxx.xx.xx.xxx but then adb claims that it was unable to connect to xxx.xx.xx.xxx:5555.
Ok, but now I'm having trouble getting it back to listening over USB. adb usb tells me that there isn't a device attached and adb devices gives me an empty list.
I've tried killing the adb server and then restarting it, toggling the device's debugging mode and toggling the device's USB storage transfer but nothing seems to be working. This question seems very similar to my problem but I have no idea what the guy is doing in the solution.
I'm guessing the problem is that adb is still trying to listen through Wifi but since I can't connect to it over Wifi it can never go back to listening to it over USB. Idk...

For wifi, you may be able to get it to work if you first use the browser on the device to visit a webpage or something and so effectively wake up the wifi radio and its connection to the access point. You may need to keep doing this every once in a while.
(Maybe you should listen to internet radio while you work?)
Of course your access point will have to permit peer-to-peer traffic on the local subnet. In many cases that may be the norm, but I believe an access point can be configured not to support that, and some may default to such settings. There can also be issues between wired and wireless subnets sourced from the same box.
Finally, restarting the device might get it back into USB mode.

ADB over ethernet

I have an android device which I want to connect to using ADB. For reasons that don't matter here I need it to have an ethernet connection, not wifi. The device itself refuses to have both ethernet and wifi connections at the same time.
I have been using a third party app called ADB WiFi to connect to it with ADB when it is in WiFi mode, and I have found that I can connect to it in wifi, then switch the device into ethernet, and then reconnect to the new IP, and it works.
I would dearly like to be able to connect to my device (which is often remote and hard to reach) without first switching it into wifi and back, to which end I have written my own little app which uses SU and does:
setprop service.adb.tcp.port 5555
stop adbd
start adbd
It says that it is working when I run it and produces no error messages, but I can't connect afterwards. It doesn't work in wifi mode either. After setting up a connection once using the 3rd party app, I can then use stop adbd to prevent adb working, and I can use my application above to enable it again, without wifi or 3rd party intervention, which suggests that it is doing what it thinks it is doing, but missing a one off step.
Does anyone know if there is another thing that must be set / enabled / poked in order for adbd to work? Does anyone know what I'm missing?
Thanks

Have you tried this:
adb tcpip 5555
adb connect 192.168.1.1:5555
replacing the 192.168.1.1 with your phones IP Address?

I was able to get both ADB (through USB) and Ethernet, but it was device specific. I used the Asus Transformer Pad TF701T with the keyboard dock. The dock allowed me to connect the ADB cable and provided a full size USB port. I connected a compatible USB to Ethernet adapter to get Ethernet.

How do you use ADB TCP/IP with USB debugging UNCHECKED?

I am trying to debug some USB attach/detach Intents while using USB Accessory mode to some custom Host hardware. I am able to connect ADB via WiFi TCP/IP and it works great. However, when a USB attach/detach Intent comes along, the ADB connection is broken - even though ADB is not running over USB at all.
After reading countless threads here that dance around that topic, a common suggestion seems to be that having "USB Debugging" checked in Settings will make the ADB connection sensitive to USB. Several posts suggest unchecking that box when running over WiFi/TCP. But I've tried that, and cannot associate ("adb connect 192.168.x.y") if that box is unchecked even when running over WiFi.
I have confirmed that when the box is unchecked, getprops still shows "service.adb.tcp.port 5555" like it always does. I've also tried explicitly killing and restarting the adbd daemon. Nothing works... except checking that box, at which point I can immediately connect via TCP.
So... what's the real story? I must say it FEELS likely that having that box checked would make ADB sensitive to USB even if it's not running on it. But is that box mislabeled, and instead of meaning "USB Debugging" it really means "Debugging regardless of connection type"? I really need to make ADB ignore the USB connection so I can debug attach/detach events. Any help appreciated. Thanks!

Access Android device via ADB with DEBUG mode OFF

I am just wondering if anyone one knows a method to access/get into an Android tablet (adb shell) if the USB DEBUG mode is off.
I have these devices that I gotta recalibrate the screens but I cannot seem to be able to click anything as the calibration is way off and USB DEBUG has been switched off. Bluetooth is off as well. Moreover screen is not responsive.

You can connect through WiFi or Ethernet.
If the ADB server is started on the tablet, you can run "adb connect IP_ADDR:PORT", PORT is optional, default 5555 and depends on your ADB server.