lopy4 Bluetooth low energy receiving data

[zhongyuan ren]

I am a beginner in lopy
I am trying to send pysense data from BLE to my Android phone.
But I cannot receive my data, my code is as follows

from network import Bluetooth
import pycom
import time
from LIS2HH12 import LIS2HH12
from pysense import Pysense



py = Pysense()

pycom.heartbeat(False)
bluetooth = Bluetooth()
bluetooth.set_advertisement(name='WiPy', service_uuid=b'1234567890123456')

def conn_cb (bt_o):
    events = bt_o.events()
    if  events & Bluetooth.CLIENT_CONNECTED:
        print("Client connected")
        pycom.rgbled(0x007f00) # green
    elif events & Bluetooth.CLIENT_DISCONNECTED:
        print("Client disconnected")
        pycom.rgbled(0x7f0000) # red

li = LIS2HH12(py)
apin = str(li.roll())


bluetooth.callback(trigger=Bluetooth.CLIENT_CONNECTED | Bluetooth.CLIENT_DISCONNECTED, handler=conn_cb)

bluetooth.advertise(True)

srv1 = bluetooth.service(uuid=b'1234567890123456', isprimary=True)

chr1 = srv1.characteristic(uuid=b'ab34567890123456', value=25)

char1_read_counter = 0
def char1_cb_handler(chr):
    global char1_read_counter
    char1_read_counter += 1

    events = chr.events()
    if  events & Bluetooth.CHAR_WRITE_EVENT:
        print("Write request with value = {}".format(value()))
    else:
        if char1_read_counter < 3:
            print('Read request on char 1')
        else:
            return 'ABC DEF'

char1_cb = chr1.callback(trigger=Bluetooth.CHAR_WRITE_EVENT | Bluetooth.CHAR_READ_EVENT, handler=char1_cb_handler)

srv2 = bluetooth.service(uuid=1234, isprimary=True)

chr2 = srv2.characteristic(uuid=4567, value=0x1234)
char2_read_counter = 0xF0
def char2_cb_handler(chr):
    global char2_read_counter
    char2_read_counter += 1
    if char2_read_counter > 0xF1:
        return char2_read_counter

char2_cb = chr2.callback(trigger=Bluetooth.CHAR_READ_EVENT, handler=char2_cb_handler)

while True:
    time.sleep(10)
    dy = round(apin)
    print(dy)
    if char1_read_counter:
        chr1.value(dy)

[jcaron]

@zhongyuan-ren what are you connecting/reading with, and happens exactly?

[zhongyuan ren]

@jcaron
Now I just did a test, the value is the voltage
I am making an APP that cannot accept data. I can see the received data using nrf, but there will be a string of codes in front of it.