Establishing Arduino Serial Connection Via USB with Kivy on Android Using Python

Projects General Guidance
1

I was using pyserial for testing the Arduino connection on Linux via a USB cable, and it worked fine. However, after converting the project into an APK using Buildozer, I added USB permissions using this code i got deivce permission

from jnius import autoclass, cast
from android.permission import request_permissions, Permission

def find_arduino_device():
    
    """Find and return the Arduino device."""
    try:
        print("Initializing USB Manager...")
        UsbManager = autoclass('android.hardware.usb.UsbManager')
        activity = autoclass('org.kivy.android.PythonActivity').mActivity
        usb_manager = cast(UsbManager, activity.getSystemService(activity.USB_SERVICE))

        # Request USB permissions
        print("Requesting permissions for USB access...")
        request_permissions([
            "android.permission.USB_PERMISSION"
        ])

        print("Fetching the list of connected USB devices...")
        device_list = usb_manager.getDeviceList()
        print(f"Device list retrieved: {device_list}")

        # Loop through devices to find Arduino
        for entry in device_list.entrySet():
            device_name = entry.getKey()
            device = entry.getValue()
            vid = device.getVendorId()
            pid = device.getProductId()
            print(f"Device found: {device_name}, VID: {vid}, PID: {pid}")

            # Replace with the correct Vendor ID and Product ID for your Arduino
            if vid == 9025 and pid == 67:
                print("Arduino device detected.")
                print(f"Checking permissions for {device_name}...")
                
                usb_manager.requestPermission(device, None)
                time.sleep(5)
                # Check for permission
                if usb_manager.hasPermission(device):
                    print(f"Permission granted for device: {device_name}")
                    return device

I have successfully detected the device and obtained the necessary permissions. How can I establish a serial connection with a baud rate of 9600 to control the Arduino? I am struggling with this and would appreciate any suggestions.

2

Use serial monitor, and a `Serial.begin(9600); in setup. Serial.print in the code will transmit data.
Serial.read in various ways can be used for incoming data.
Check Arduino/reference/serial. for more information.

3

I successfully established a connection with Arduino using a Kivy frontend and PySerial on Ubuntu, and everything works fine. However, when converting the app into an APK for Android, PySerial doesn't support finding and making serial connections on Android. I need guidance on how to establish a serial connection in Python for Android. Any suggestions?