Enable Device Debug

Enable developer mode on your Android device

Settings ⇒ System ⇒ About Phone ⇒ Tap "Build number" over 7 times and quickly
Then you will see "You are already developer"

Enable debugging

Go to "Developer Options" ⇒ Enable "ADB debugging"
Connect Android phone to your Windows PC, then you will see a pop-up ( some phone will not show pop-up, please check notification center)
Choose "Transfer files"

adb Setup

Windows

Download adb package for windows. https://developer.android.com/studio/releases/platform-tools.html
Unzip the package, then put it to any path

    cd C:\{adb folder path}

Mac

Download adb package for mac. https://developer.android.com/studio/releases/platform-tools.html
Install adb
Open terminal

Check installation success

Type

adb

If you can see below message, means adb is able to use

    Android Debug Bridge version 1.0.40
    Version 4986621
    Installed as C:\{adb folder path}\adb\adb.exe

    global options:
     -a         listen on all network interfaces, not just localhost
     -d         use USB device (error if multiple devices connected)
     -e         use TCP/IP device (error if multiple TCP/IP devices available)
     -s SERIAL  use device with given serial (overrides $ANDROID_SERIAL)
     -t ID      use device with given transport id
     -H         name of adb server host [default=localhost]
     -P         port of adb server [default=5037]
     -L SOCKET  listen on given socket for adb server [default=tcp:localhost:5037]

adb command

Connect your Android phone to PC/MAC, then type

    adb devices

If you see below message, means your Android phone already connected to PC, and able to use adb command

    List of devices attached
    35PDU18712000000        device

Send text to device

    adb shell input text "textttt"

Send key to device.
You can use key name or key code. eg: TAB(61), HOME(3), ENTER(66)
https://developer.android.com/reference/android/view/KeyEvent

    adb shell input keyevent TAB
    adb shell input keyevent 61

Log ( logcat) https://developer.android.com/studio/command-line/logcat