flutter and pico code for 
android accelerometer and bluetooth demo

/*************************
 * main.dart 
 *************************/
import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'package:get/get.dart';
import './home.dart';

void main() {
  WidgetsFlutterBinding.ensureInitialized(); 
  SystemChrome.setPreferredOrientations([ // portrait only
    DeviceOrientation.portraitUp,
    DeviceOrientation.portraitDown]);
  runApp(MyApp());}
  
class MyApp extends StatelessWidget{
  MyApp({super.key});
  @override Widget build(BuildContext context){
    return GetMaterialApp(
      title: 'Flutter Template',
      debugShowCheckedModeBanner: false,
      theme: ThemeData(
        useMaterial3: true),
        home: Home());}}
        
/*************
 * home.dart
 *************/
import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'package:get/get.dart';
import './accel.dart';
import './source.dart';

class Home extends StatelessWidget{

@override Widget build(BuildContext context){
  return Scaffold(
  appBar:AppBar(title: Text('Ble with accel')),
  drawer: Drawer(child: ListView(children: [
  
    ListTile(title: Text('Accel'),
      onTap:() {Get.to(Accel());}),

    ListTile(title: Text('Source'),
      onTap:() {Get.to(Source());}), 
      
    ListTile(title: Text('Exit'),
      onTap:(){ SystemNavigator.pop(); })])),
      
  body: Center(child: SingleChildScrollView(child: Text('''
  
  demo using phones accelerometer sending values
  to pico using bluetooth'''))));}}
  
/********************
 * accel.dart
 ********************/
import 'package:flutter/material.dart';
import 'dart:async';
import 'dart:typed_data';
import 'package:get/get.dart';
import 'package:sensors_plus/sensors_plus.dart';
import 'package:flutter_reactive_ble/flutter_reactive_ble.dart';
import 'ble_controller.dart';

class Accel extends StatefulWidget { 
const Accel({super.key}); 
@override State<Accel> createState() => AccelState();} 

class AccelState extends State<Accel> {
  AccelerometerEvent? accel;
  late StreamSubscription<AccelerometerEvent> subs;
  late Timer timer; 
  List<int> packet=[0,0];
  late BleController ble;
  late int x, old_x;
  late int y, old_y;

void sendX(int x){
      if (x > 2) packet[1] = 0x6c;
      else if (x < -2) packet[1] = 0x72;
      else if (x == 0) packet[1] = 0x6d;
      ble.send(packet);
}

void sendY(int y){
      if (y > 2) packet[1] = 0x32;
      else if (y < -2) packet[1] = 0x33;
      else if (y == 0) packet[1] = 0x31;
      ble.send(packet);
}

@override void dispose(){
  super.dispose();
  subs.cancel();
  timer.cancel();}

  @override void initState() {
    old_x = 0;
    old_y = 0;
	super.initState();
	subs = accelerometerEventStream().listen((AccelerometerEvent event){
	  setState((){ accel = event; });});
  
  // update bluetooth packet
  timer = Timer.periodic(const Duration(milliseconds: 200), (_) {
    setState(() {
      x = accel!.x.toInt();
      if (old_x != x) { sendX(x); old_x = x;}
      
      y = accel!.y.toInt();
      if (old_y != y) {sendY(y); old_y = y;}

    });});}

@override 
Widget build(BuildContext context) {
  ble = Get.put(BleController());
  return Scaffold(appBar: AppBar(title: Text('Accelerometer Example')), 
	body: Center(child: Column( 
	  mainAxisAlignment: MainAxisAlignment.center, 
	  children: <Widget>[ 
	  
	    ElevatedButton(child: Obx(() => Text('${ble.status.value}')),
	      onPressed: ble.connect),
	  
	    SizedBox(height:20),
	  
	    Text('Accelerometer Data:',style: TextStyle(fontSize: 20)),
			 
		SizedBox(height: 10),
			
		Text('X: ${accel!.x.toInt()}, '
		         'Y: ${accel!.y.toInt()}',)
])));}} 
/***************
 * source.dart
 ***************/
import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'package:get/get.dart';
import 'package:flutter_syntax_view/flutter_syntax_view.dart';
import 'dart:async';
import 'dart:io';
import 'dart:convert';
import './codes.dart';

// function to show source code
Widget showSource(String code, BuildContext context){
  num line = LineSplitter().convert(code).length;
  return  SizedBox(height:16.0 * line, child:SyntaxView(
      code: code,
      syntax: Syntax.DART,
      syntaxTheme: SyntaxTheme.vscodeDark(),
      withZoom:true,
      withLinesCount:true,
      expanded:true));}

class Source extends StatelessWidget{

@override Widget build(BuildContext context) {
return Scaffold(appBar:AppBar(title: Text('Source Code')),
body: SingleChildScrollView(child:Column(children:[

for (var i=0; i<codes.length; i++) Column(children:[
    showSource(codes[i], context),
    SizedBox(height:40)])])));}}
/**********************
 * ble_controller.dart
 **********************/
import 'package:flutter/material.dart';
import 'package:flutter_reactive_ble/flutter_reactive_ble.dart';
import 'package:get/get.dart';
import 'dart:async';
import 'dart:typed_data';
import 'dart:convert';
import 'dart:io';

class BleController extends GetxController {
final frb = FlutterReactiveBle();
late StreamSubscription<ConnectionStateUpdate> c;
late QualifiedCharacteristic tx;
var status = 'connect to bluetooth'.obs;

void send(val) async{
await frb.writeCharacteristicWithoutResponse(tx, value: val);}    

void connect() async {
status.value = 'connecting...';
c = frb.connectToDevice(id: 'CC:33:31:CF:74:72').listen((state) {
if (state.connectionState == DeviceConnectionState.connected) {
status.value = 'connected';
tx=QualifiedCharacteristic(
serviceId: Uuid.parse("FFE0"),
characteristicId: Uuid.parse("FFE1"),
deviceId: 'CC:33:31:CF:74:72');}});}}

/*************
 * codes.dart
 *************/
// main.dart
// home.dart
// accel.dart
// source.dart
// ble_controller.dart

List<String> codes = [
////////////// main.dart
'''
/*************************
 * main.dart 
 *************************/
import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'package:get/get.dart';
import './home.dart';

void main() {
  WidgetsFlutterBinding.ensureInitialized(); 
  SystemChrome.setPreferredOrientations([ // portrait only
    DeviceOrientation.portraitUp,
    DeviceOrientation.portraitDown]);
  runApp(MyApp());}
  
class MyApp extends StatelessWidget{
  MyApp({super.key});
  @override Widget build(BuildContext context){
    return GetMaterialApp(
      title: 'Flutter Template',
      debugShowCheckedModeBanner: false,
      theme: ThemeData(
        useMaterial3: true),
        home: Home());}}
''',

////////////// home.dart
'''
/*************
 * home.dart
 *************/
import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'package:get/get.dart';
import './accel.dart';
//import './help.dart';
//import './source.dart';

class Home extends StatelessWidget{

@override Widget build(BuildContext context){
  return Scaffold(
  appBar:AppBar(title: Text('Ble with accel')),
  drawer: Drawer(child: ListView(children: [
  
    ListTile(title: Text('Accel'),
      onTap:() {Get.to(Accel());}),

    ListTile(title: Text('Source'),
      onTap:() {Get.to(Source());}), 
      
    ListTile(title: Text('Exit'),
      onTap:(){ SystemNavigator.pop(); })])),
      
  body: Center(child: SingleChildScrollView(child: Text(3 single quotes
  
  demo using phones accelerometer sending values
  to pico using bluetooth
  
  3 single quotes)));}}
''',

////////////// accel.dart
'''
/********************
 * accel.dart
 ********************/
import 'package:flutter/material.dart';
import 'dart:async';
import 'dart:typed_data';
import 'package:get/get.dart';
import 'package:sensors_plus/sensors_plus.dart';
import 'package:flutter_reactive_ble/flutter_reactive_ble.dart';
import 'ble_controller.dart';

class Accel extends StatefulWidget { 
const Accel({super.key}); 
@override State<Accel> createState() => AccelState();} 

class AccelState extends State<Accel> {
  AccelerometerEvent? accel;
  late StreamSubscription<AccelerometerEvent> subs;
  late Timer timer; 
  List<int> packet=[0,0];
  late BleController ble;
  late int x, old_x;
  late int y, old_y;

void sendX(int x){
      if (x > 2) packet[1] = 0x6c;
      else if (x < -2) packet[1] = 0x72;
      else if (x == 0) packet[1] = 0x6d;
      ble.send(packet);
}

void sendY(int y){
      if (y > 2) packet[1] = 0x32;
      else if (y < -2) packet[1] = 0x33;
      else if (y == 0) packet[1] = 0x31;
      ble.send(packet);
}

@override void dispose(){
  super.dispose();
  subs.cancel();
  timer.cancel();}

  @override void initState() {
    old_x = 0;
    old_y = 0;
	super.initState();
	subs = accelerometerEventStream().listen((AccelerometerEvent event){
	  setState((){ accel = event; });});
  
  // update bluetooth packet
  timer = Timer.periodic(const Duration(milliseconds: 200), (_) {
    setState(() {
      x = accel!.x.toInt();
      if (old_x != x) { sendX(x); old_x = x;}
      
      y = accel!.y.toInt();
      if (old_y != y) {sendY(y); old_y = y;}

    });});}

@override 
Widget build(BuildContext context) {
  ble = Get.put(BleController());
  return Scaffold(appBar: AppBar(title: Text('Accelerometer Example')), 
	body: Center(child: Column( 
	  mainAxisAlignment: MainAxisAlignment.center, 
	  children: <Widget>[ 
	  
	    ElevatedButton(child: Obx(() => Text('\${ble.status.value}')),
	      onPressed: ble.connect),
	  
	    SizedBox(height:20),
	  
	    Text('Accelerometer Data:',style: TextStyle(fontSize: 20)),
			 
		SizedBox(height: 10),
			
		Text('X: \${accel!.x.toInt()}, '
		         'Y: \${accel!.y.toInt()}',)
])));}} 

''',

///////////// ble.dart
'''

''',

///////////// ble_controller.dart
'''
/**********************
 * ble_controller.dart
 **********************/
import 'package:flutter/material.dart';
import 'package:flutter_reactive_ble/flutter_reactive_ble.dart';
import 'package:get/get.dart';
import 'dart:async';
import 'dart:typed_data';
import 'dart:convert';
import 'dart:io';

class BleController extends GetxController {
final frb = FlutterReactiveBle();
late StreamSubscription<ConnectionStateUpdate> c;
late QualifiedCharacteristic tx;
var status = 'connect to bluetooth'.obs;

void send(val) async{
await frb.writeCharacteristicWithoutResponse(tx, value: val);}    

void connect() async {
status.value = 'connecting...';
c = frb.connectToDevice(id: 'CC:33:31:CF:74:72').listen((state) {
if (state.connectionState == DeviceConnectionState.connected) {
status.value = 'connected';
tx=QualifiedCharacteristic(
serviceId: Uuid.parse("FFE0"),
characteristicId: Uuid.parse("FFE1"),
deviceId: 'CC:33:31:CF:74:72');}});}}
''',
///////// source.dart
'''
/***************
 * source.dart
 ***************/
import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'package:get/get.dart';
import 'package:flutter_syntax_view/flutter_syntax_view.dart';
import 'dart:async';
import 'dart:io';
import 'dart:convert';
import './codes.dart';

// function to show source code
Widget showSource(String code, BuildContext context){
  num line = LineSplitter().convert(code).length;
  return  SizedBox(height:16.0 * line, child:Padding(
      padding:EdgeInsets.fromLTRB(0,0,20,0), child:SyntaxView(
      code: code,
      syntax: Syntax.DART,
      syntaxTheme: SyntaxTheme.vscodeDark(),
      withZoom:true,
      withLinesCount:true,
      expanded:true)));}

class Source extends StatelessWidget{

@override Widget build(BuildContext context) {
return Scaffold(appBar:AppBar(title: Text('Source Code')),
body: SingleChildScrollView(child:Column(children:[

for (var i=0; i<codes.length; i++) Column(children:[
    showSource(codes[i], context),
    SizedBox(height:40)])])));}}
''',

'''
/*******************
 * micropython code
 *******************/
# python code for receiving uart data
#   also servo code using MG 996R

from machine import Pin,PWM,UART
import time

print('starting...')
u=UART(0,baudrate=9600,tx=Pin(0),rx=Pin(1))
s1=PWM(Pin(14))
s2=PWM(Pin(15))
buf=bytearray(2)
s1.freq(50)
s2.freq(50)
s1.duty_u16(5300) # bottom servo middle
s2.duty_u16(5300) # top servo middle

while 1:
    time.sleep_ms(50)
    buf=u.read(2)
    if buf is not None:
        print(buf)
        if buf == b'\x00l': s1.duty_u16(6300)
        elif buf == b'\x00r': s1.duty_u16(4300)
        elif buf == b'\x00m': s1.duty_u16(5300)
        elif buf == b'\x001': s2.duty_u16(5300)
        elif buf == b'\x002': s2.duty_u16(4300)
        elif buf == b'\x003': s2.duty_u16(6300)
 
'''
];