2021A/main.py

from kivy.app import App
from kivy.uix.widget import Widget
from kivy.uix.button import Button
from kivy.uix.gridlayout import GridLayout
from kivy.uix.label import Label
from kivy.uix.textinput import TextInput
from kivy.clock import Clock

import asyncio
from bleak import BleakClient,BleakScanner
import json

STM32_UUID = "00001101-0000-1000-8000-00805F9B34FB"

class MainWidget(Widget):
    def __init__(self, **kwargs):
        super().__init__(**kwargs)
        self.size = (1600,800)
        self.last_flag = False
        self.flag = False
        self.scanning = Label(text="Scanning...",font_size=100,top=self.top,center_x = self.center_x)

    def update(self, dt):
        if self.flag and (not self.last_flag):
            self.connect()
        self.last_flag = self.flag

    def start(self):
        self.add_widget(self.scanning)

    # def start_scan(self, dt):
    #     asyncio.run(self.scan)

    async def scan(self):
        self.devices = await BleakScanner.discover()
        self.flag = True

    def connect(self):
        self.remove_widget(self.scanning)
        self.grid00 = GridLayout(cols=1,rows=2,width=self.width,height=self.height / 4,top=self.top)
        self.add_widget(self.grid00)
        grid01 = GridLayout(cols=2,rows=1,width=self.grid00.width,height=self.grid00.height / 2)
        self.grid00.add_widget(grid01)
        grid01.add_widget(Label(text="Device Name:",width=self.grid00.width / 2,height=self.grid00.height / 2,font_size=50))
        deviceName = "HC-06"
        grid01.add_widget(TextInput(text=deviceName,width=self.grid00.width / 2,height=self.grid00.height / 2,font_size=40))
        connect_button = Button(text="Connect",width=self.grid00.width,height=self.grid00.height / 2,center_x=self.grid00.center_x,font_size=40)
        self.grid00.add_widget(connect_button)
        if connect_button.state == "down":
            self.clear_widgets(self.grid00)

class STI2021A(App):
    def __init__(self):
        super().__init__()
        self.main_widget = MainWidget()

    def build(self):
        self.main_widget.start()
        Clock.schedule_interval(self.main_widget.update, 1)
        return self.main_widget
    
    async def scan(self):
        await self.main_widget.scan()

async def main(app):
    await asyncio.gather(app.async_run("asyncio"), app.scan())

if __name__ == "__main__":
    app = STI2021A()
    asyncio.run(main(app))