#filename:uart_test.py
#uses hm19 ble module - amazon item #8541588324
#pico pin4       - hm-19 rxd
#pico pin5       - hm-19 txd
#pico pin40      - hm-19 vcc
from machine import UART,Pin,ADC
import time
uart=UART(1,9600)
led = Pin(25,Pin.OUT)
temp = ADC(4) 
while 1:
    time.sleep_ms(500)
    uart.write(str(temp.read_u16()))
    if uart.any() > 0:
        try:
            a,b = uart.read()
            if int(a) == 36 and int(b) == 84: led.toggle()
        except Exception as error:
            pass
           
//filename: main.dart
// ble demo
// flutter:
//    change minsdk to 21
//    make sure bluetooth is on
//    give location permission to app

import 'package:flutter/material.dart';
import 'package:flutter_reactive_ble/flutter_reactive_ble.dart';
import 'ble.dart';
import 'sendbutton.dart';
import 'connectbutton.dart';
import 'readbutton.dart';

void main() {
  runApp(MyApp());
}

class MyApp extends StatelessWidget {
  // This widget is the root of your application.
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      home: MyHomePage(title: 'BLE demo'),);}}

class MyHomePage extends StatefulWidget {
  MyHomePage({Key? key, required this.title}) : super(key: key);
  final String title;
  @override
  MyHomePageState createState() => MyHomePageState();}

class MyHomePageState extends State<MyHomePage> with TickerProviderStateMixin {

  late TabController tabController;
  BLE ble = BLE();
  String status = 'not connected';
  
  @override
  void initState(){
    super.initState();
    ble.connectToBLE();
    tabController = TabController(length: 3, vsync: this);
    tabController.addListener((){
      setState((){
        status = ble.getStatus();
      });
    });
  }
  
  @override
  Widget build(BuildContext context) {
    status = ble.getStatus();
    return Scaffold(
      appBar: AppBar(
        title: Text(widget.title),
        backgroundColor: Colors.black,
        bottom: TabBar(
          controller: tabController,
          indicator: BoxDecoration(
            borderRadius: BorderRadius.circular(50),
            color: Colors.greenAccent),
          tabs: const <Widget>[
            Tab(icon: Icon(Icons.home)),
            Tab(icon: Icon(Icons.light_mode)),
            Tab(icon: Icon(Icons.thermostat)),],),),
          
      body: TabBarView(
        controller: tabController,
        children: <Widget>[
        
            ConnectButton(ble, status),
              
            SendButton(ble),

            ReadButton(ble)

        ]));}}
        
// filename: ble.dart
import 'package:flutter/material.dart';
import 'package:flutter_reactive_ble/flutter_reactive_ble.dart';
import 'dart:async';

class BLE{

  BLE(); 
  final frb = FlutterReactiveBle();
  StreamSubscription? subscription;
  late StreamSubscription<ConnectionStateUpdate> connection;
  late QualifiedCharacteristic tx;
  late QualifiedCharacteristic rx;
  String status = 'not connected';
  static final String BASE = "-0000-1000-8000-00805f9b34fb";
  static int response = 0;
  int value = 0;

  Future<void> stopScan() async {
    await subscription?.cancel();
    subscription = null;}
  
  String getStatus(){
    return status;}
  
  void sendData() async {
    await frb.writeCharacteristicWithoutResponse(tx, value:[0x24,0x54]);}

   int readData() { return response; }

 void connectToBLE() async {
    subscription = frb.scanForDevices(withServices:
      [Uuid.parse("0000ffe0"+BASE)]).listen((device){   
        connection = frb.connectToDevice(id: device.id).listen((state){
          if (state.connectionState == DeviceConnectionState.connected) {
          
            // get tx
            tx = QualifiedCharacteristic(
              serviceId: Uuid.parse("0000ffe0"+BASE),            
              characteristicId: Uuid.parse("0000ffe1"+BASE), 
              deviceId: device.id);
              
             // get rx
             rx = QualifiedCharacteristic(
              serviceId: Uuid.parse("0000ffe0"+BASE),            
              characteristicId: Uuid.parse("0000ffe1"+BASE), 
              deviceId: device.id);
              
              // subscribe to rx
              frb.subscribeToCharacteristic(rx).listen((data){
                value = 0;
                value += (data[0] - 48).toUnsigned(8) * 10000;
                value += (data[1] - 48).toUnsigned(8) * 1000;
                value += (data[2] - 48).toUnsigned(8) * 100;
                value += (data[3] - 48).toUnsigned(8) * 10;
                value += (data[4] - 48).toUnsigned(8) * 1;

                response = value;
              }, onError:(Object e){
                print('subscribe error: $e\n');
              });
              
            status = 'connected';
            stopScan();}
        }, onError: (Object e) { // connecting error
          print('error: $e\n');
        });     
      }, onError:(Object e){ // scan error
        print('error: $e\n');});}}
        
///////////////////////////// filename: connectbutton.dart
import 'package:flutter/material.dart';
import 'ble.dart';

class ConnectButton extends StatelessWidget {

  final BLE ble;
  final String status;
  ConnectButton(this.ble, this.status);

  @override
  Widget build(BuildContext c){
    return Column(
      children: <Widget>[
        SizedBox(height:50),
        Text('status: $status'),
        SizedBox(height:50),
        Text('make sure bluetooth is on\ngive location permission to the app\nchange build.gradle minSkVersion to 21\ndemo uses flutter_reactive_ble 3.1.1', style: TextStyle(fontSize:35, fontWeight:FontWeight.bold)),
        SizedBox(height:50),
        Text('flutter_reactive_ble 3.1.1', style: TextStyle(fontSize:30))]);}}

/////////////////////// filename: sendbutton.dart
import 'package:flutter/material.dart';
import 'ble.dart';

class SendButton extends StatelessWidget {

  final BLE ble;
  SendButton(this.ble);

  @override
  Widget build(BuildContext c){
    return Column(children: <Widget>[
      SizedBox(height:70),
      ElevatedButton(
        child: Text('toggle led',style:TextStyle(fontSize:40,fontWeight:FontWeight.bold)),
      onPressed: ble.sendData)]);}}

/////////////// filename: readbutton.dart
import 'package:flutter/material.dart';
import 'ble.dart';

class ReadButton extends StatefulWidget {

  final BLE ble;
  ReadButton(this.ble);

  @override
  ReadButtonState createState() => ReadButtonState();}
  
class ReadButtonState extends State<ReadButton> {
  int value = 0;
  double farenheit = 0.0;
  String s = ' ';

  @override
  Widget build(BuildContext c){
    return Column(
      children: <Widget>[
        SizedBox(height:70),
        ElevatedButton(
          child: Text('read picos temp'),
          onPressed:() {
            value = widget.ble.readData();
            farenheit = value.toDouble();
            farenheit *= 3.3 / (65535);
            farenheit = 27 - (farenheit - 0.706) / 0.001721;
            farenheit = farenheit * (9 / 5) + 32;
            farenheit = double.parse((farenheit).toStringAsFixed(2));         
            setState((){
              s = farenheit.toString();
            });
          },),
          SizedBox(height:70),
          Text('pico temp: $s', style: TextStyle(fontSize:40,
            fontWeight: FontWeight.bold,
            color: farenheit > 72.00 ? Colors.red : Colors.green))      
      ]);}}