Automating Princess Connect on Android with Python, ADB, and OpenCV

The article explains how a programmer can automate the initial‑account tasks of the mobile game Princess Connect by writing Python scripts that control an Android device via ADB and perform image recognition with OpenCV, instead of using higher‑level tools like Airtest.

Preparation : You need an Android device (emulator or real phone), ADB installed and added to PATH , tesseract‑ocr for OCR, and Python 3.7+. Install required Python libraries with pip install pillow pytesseract opencv-python ; uiautomator2 is optional.

Connecting to the device : Use adb devices to list connected devices, then adb shell to verify you can enter the device shell. If the shell fails, run adb kill-server and retry.

Common ADB commands include taking screenshots, pulling and pushing files, tapping the screen, inputting text, deleting characters, querying the current package/activity, and stopping/starting apps.

Screenshot example:

def take_screenshot():
    os.system("adb shell screencap -p /data/screenshot.png")
    os.system("adb pull /data/screenshot.png ./tmp.png")

Pulling a file (e.g., the game’s XML preferences):

os.system(f"adb pull /data/data/tw.sonet.princessconnect/shared_prefs/tw.sonet.princessconnect.v2.playerprefs.xml ./user_info.xml")

Pushing a file to switch accounts:

# Switch to account 1
os.system("adb push ./user_info1.xml /data/data/tw.sonet.princessconnect/shared_prefs/tw.sonet.princessconnect.v2.playerprefs.xml")

# Switch to account 2
os.system("adb push ./user_info2.xml /data/data/tw.sonet.princessconnect/shared_prefs/tw.sonet.princessconnect.v2.playerprefs.xml")

Tap a screen coordinate :

def adb_click(center, offset=(0, 0)):
    (x, y) = center
    x += offset[0]
    y += offset[1]
    os.system(f"adb shell input tap {x} {y}")

Input text and delete characters :

text = "YourPassword"
os.system(f"adb shell input text {text}")

# Delete 10 characters
for i in range(10):
    os.system("adb shell input keyevent 67")

Query running package/activity :

adb shell dumpsys activity activities

Stop and start an app :

adb shell am force-stop tw.sonet.princessconnect
adb shell am start -W -n tw.sonet.princessconnect/jp.co.cygames.activity.OverrideUnityActivity

Image template matching using OpenCV:

import cv2

def image_to_position(screen, template):
    image_x, image_y = template.shape[:2]
    result = cv2.matchTemplate(screen, template, cv2.TM_CCOEFF_NORMED)
    min_val, max_val, min_loc, max_loc = cv2.minMaxLoc(result)
    print("prob:", max_val)
    if max_val > 0.98:
        global center
        center = (max_loc[0] + image_y / 2, max_loc[1] + image_x / 2)
        return center
    else:
        return False

if __name__ == "__main__":
    screen = cv2.imread('tmp.png')
    template = cv2.imread('Xuandan.png')
    print(image_to_position(screen, template))

The script reports a matching probability of 0.9977 and a position near the bottom‑right corner of a 1280×720 screenshot.

Cropping a screenshot to obtain a template with PIL:

from PIL import Image

def crop_screenshot(img_file, pos_x, pos_y, width, height, out_file):
    img = Image.open(img_file)
    region = (pos_x, pos_y, pos_x + width, pos_y + height)
    cropImg = img.crop(region)
    cropImg.save(out_file)
    print("exported:", out_file)

if __name__ == "__main__":
    crop_screenshot("tmp.png", 817, 556, 190, 24, "test_id.png")

This example extracts the player’s ID area from the screenshot.

Simple OCR with pytesseract:

from PIL import Image
import pytesseract

image = Image.open('test_id.png')
content = pytesseract.image_to_string(image)
print(content)

Note that the OCR result may contain spaces and line breaks that need to be filtered before use.

Conclusion : The article provides a practical guide to using ADB and basic image‑processing techniques for mobile game automation, covering device setup, command‑line interaction, screenshot handling, template matching, cropping, and OCR.