Receive data via bluetooth using python on android phone

Question

I have an ESP32 board which sends data via bluetooth. I can receive data on PC using this python code:

from bluetooth import *
import sys


def input_and_send():
    while True:
        data = input()
        if len(data) == 0: break
        sock.send(data)
        sock.send("\n")
        
def rx_and_echo():
    sock.send("\nsend anything\n")
    while True:
        data = sock.recv(buf_size)
        if data:
            print(data.decode('utf-8'))
            sock.send(data)
            
addr = "XX:XX:XX:XX:XX:XX"
service_matches = find_service( address = addr )
buf_size = 1024
if len(service_matches) == 0:
    print("couldn't find the SampleServer service =(")
    sys.exit(0)

for s in range(len(service_matches)):
    print("\nservice_matches: [" + str(s) + "]:")
    print(service_matches[s])

first_match = service_matches[0]
port = first_match["port"]
name = first_match["name"]
host = first_match["host"]
port = 1
print("connecting to \"%s\" on %s, port %s" % (name, host, port))
sock = BluetoothSocket(RFCOMM)
sock.connect((host, port))
print("connected")

# input_and_send()
rx_and_echo()
sock.close()
Data.append(data.decode('utf-8'))

Now, I want to get data on android phone. I wrote a python program using kivy, but bluetooth package does not work on android. I tried bleak and jnius packages, but they did not work. Is there another packages which can use bluetooth of phone properly? I see, some persons advise using jnius package for android , but I could not get data using "BluetoothReceive" function. Any help is appreciated.

Answer 1

I understood how to receive data using python on android. I used jnius package, and tried to look errors using this code on android phone. I found the BufferReader should be used instead of getInputStream() , and readLine() instead of readline() . You can receive data using the below code:

from jnius import autoclass

BluetoothAdapter = autoclass('android.bluetooth.BluetoothAdapter')
BluetoothDevice = autoclass('android.bluetooth.BluetoothDevice')
BluetoothSocket = autoclass('android.bluetooth.BluetoothSocket')
UUID = autoclass('java.util.UUID')
BufferReader = autoclass('java.io.BufferedReader')
InputStream = autoclass('java.io.InputStreamReader')

paired_devices = BluetoothAdapter.getDefaultAdapter().getBondedDevices().toArray()
socket = None
for device in paired_devices:
    if device.getName() == 'ESP32':
        socket = device.createRfcommSocketToServiceRecord(
        UUID.fromString("00001101-0000-1000-8000-00805F9B34FB"))
        recv_stream = BufferReader(InputStream(socket.getInputStream()))
        break
socket.connect()
Serial_Data = recv_stream.readLine()

Add this bluetooth permision to your buildozer.spec file.

android.permissions = BLUETOOTH, BLUETOOTH_ADMIN, ACCESS_FINE_LOCATION

Since jnius package does not work on PC (Windows or Linux), I hope there be another way to debug the python code directly, without making application and testing it on android phone.