KeiichiOnishi — Interface and Application Programming

Step 1: Programming Attiny 44 with Ardino IDE

The App's function is sending signals from Android phone to turn LED light ON and OFF. What I need to do in microcontoller side are 1) setting up bluetooth serial communication and 2) defining input and output pins assignment.

Here is my source code

// // hello.bluetooth_m_2.44.c // // Bluetooth controlled LED light // // Keiichi Onishi // 12/1/2014 // /* This code will run the bluetooth as slave pressing 1 turns on led 3 pressing 0 turns off led 3 */ #include <avr/io.h> #include <util/delay.h> #include <SoftwareSerial.h> //Software Serial Port #define led_delay() _delay_ms(100) //LED delay // Pins used for inputs and putputs #define RxD A4 #define TxD A5 #define led A3 #define DEBUG_ENABLED 1 SoftwareSerial blueToothSerial(RxD,TxD); //Char used for reading in Serial characters char inbyte = 0; void setup(){ // initialise serial communications at 9600 bps: blueToothSerial.begin(9600); pinMode(RxD, INPUT); pinMode(TxD, OUTPUT); pinMode(led, OUTPUT); digitalWrite(led,LOW); } void loop() { //when serial values have been received this will be true if (blueToothSerial.available() > 0) { inbyte = blueToothSerial.read(); if (inbyte == '0') { //LED off digitalWrite(led, LOW); } if (inbyte == '1') { //LED on digitalWrite(led, HIGH); } } //delay by 0.2s. Meaning we will be sent values every 0.2s approx //also means that it can take up to 0.2 seconds to change LED state delay(200); }

Step 2: Programming Android App: SimpleBluetooth

Here is an exciting part, Android App development! First, you download and install Android Studio following instruction. The process is pretty straightforward if you follow the instruction. It's currently in beta but will be the official Android IDE once it's ready. As the ADT plugin for Eclipse is no longer in active development, using Android Studio would be better option if you are new to Android development. As for bluetooth communication, this tutorial provided by Google is quite useful. You can refer some sample codes on the website as well.

Here is my source code

AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?> <manifest xmlns:android="http://schemas.android.com/apk/res/android" package="com.example.keiichionishi.simplebluetooth" > <uses-sdk android:minSdkVersion="10" android:targetSdkVersion="19" /> <uses-permission android:name="android.permission.BLUETOOTH"/> <uses-permission android:name="android.permission.BLUETOOTH_ADMIN"/> <application android:allowBackup="true" android:icon="@drawable/ic_launcher" android:label="@string/app_name" android:theme="@style/AppTheme" > <activity android:name=".MainActivity" android:label="@string/app_name" android:screenOrientation="portrait" > </activity> <activity android:name=".DeviceListActivity" android:label="@string/app_name" > <intent-filter> <action android:name="android.intent.action.MAIN" /> <category android:name="android.intent.category.LAUNCHER" /> </intent-filter> </activity> </application> </manifest>

DeviceListActivity.java

package com.example.keiichionishi.simplebluetooth; import android.support.v7.app.ActionBarActivity; import java.util.Set; import android.app.Activity; import android.bluetooth.BluetoothAdapter; import android.bluetooth.BluetoothDevice; import android.content.Intent; import android.os.Bundle; import android.util.Log; import android.view.View; import android.widget.AdapterView; import android.widget.ArrayAdapter; import android.widget.Button; import android.widget.ListView; import android.widget.TextView; import android.widget.Toast; import android.widget.AdapterView.OnItemClickListener; public class DeviceListActivity extends Activity { // Debugging for LOGCAT private static final String TAG = "DeviceListActivity"; private static final boolean D = true; // declare button for launching website and textview for connection status Button tlbutton; TextView textView1; // EXTRA string to send on to mainactivity public static String EXTRA_DEVICE_ADDRESS = "device_address"; // Member fields private BluetoothAdapter mBtAdapter; private ArrayAdapter<String> mPairedDevicesArrayAdapter; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.device_list); } @Override public void onResume() { super.onResume(); //*************** checkBTState(); int none_paired; textView1 = (TextView) findViewById(R.id.connecting); textView1.setTextSize(40); textView1.setText(" "); // Initialize array adapter for paired devices mPairedDevicesArrayAdapter = new ArrayAdapter<String>(this, R.layout.device_name); // Find and set up the ListView for paired devices ListView pairedListView = (ListView) findViewById(R.id.paired_devices); pairedListView.setAdapter(mPairedDevicesArrayAdapter); pairedListView.setOnItemClickListener(mDeviceClickListener); // Get the local Bluetooth adapter mBtAdapter = BluetoothAdapter.getDefaultAdapter(); // Get a set of currently paired devices and append to 'pairedDevices' Set<BluetoothDevice> pairedDevices = mBtAdapter.getBondedDevices(); // Add previosuly paired devices to the array if (pairedDevices.size() > 0) { findViewById(R.id.title_paired_devices).setVisibility(View.VISIBLE);//make title viewable for (BluetoothDevice device : pairedDevices) { mPairedDevicesArrayAdapter.add(device.getName() + "\n" + device.getAddress()); } } else { // String noDevices = getResources().getText(R.string.none_paired).toString(); // mPairedDevicesArrayAdapter.add(noDevices); } } // Set up on-click listener for the list (nicked this - unsure) private OnItemClickListener mDeviceClickListener = new OnItemClickListener() { public void onItemClick(AdapterView<?> av, View v, int arg2, long arg3) { textView1.setText("Connecting..."); // Get the device MAC address, which is the last 17 chars in the View String info = ((TextView) v).getText().toString(); String address = info.substring(info.length() - 17); // Make an intent to start next activity while taking an extra which is the MAC address. Intent i = new Intent(DeviceListActivity.this, MainActivity.class); i.putExtra(EXTRA_DEVICE_ADDRESS, address); startActivity(i); } }; private void checkBTState() { // Check device has Bluetooth and that it is turned on mBtAdapter=BluetoothAdapter.getDefaultAdapter(); // CHECK THIS OUT THAT IT WORKS!!! if(mBtAdapter==null) { Toast.makeText(getBaseContext(), "Device does not support Bluetooth", Toast.LENGTH_SHORT).show(); } else { if (mBtAdapter.isEnabled()) { Log.d(TAG, "...Bluetooth ON..."); } else { //Prompt user to turn on Bluetooth Intent enableBtIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE); startActivityForResult(enableBtIntent, 1); } } } }

MainActivity.java

package com.example.keiichionishi.simplebluetooth; /** * Created by keiichionishi on 12/7/14. */ import java.io.IOException; import java.io.InputStream; import java.io.OutputStream; import java.util.UUID; import android.app.Activity; import android.bluetooth.BluetoothAdapter; import android.bluetooth.BluetoothDevice; import android.bluetooth.BluetoothSocket; import android.content.Intent; import android.os.Bundle; import android.os.Handler; import android.view.View; import android.view.View.OnClickListener; import android.widget.Button; import android.widget.TextView; import android.widget.Toast; public class MainActivity extends Activity { Button btnOn, btnOff; TextView txtArduino, txtString, txtStringLength, sensorView0, sensorView1, sensorView2, sensorView3; Handler bluetoothIn; final int handlerState = 0; //used to identify handler message private BluetoothAdapter btAdapter = null; private BluetoothSocket btSocket = null; private StringBuilder recDataString = new StringBuilder(); private ConnectedThread mConnectedThread; // SPP UUID service - this should work for most devices private static final UUID BTMODULEUUID = UUID.fromString("00001101-0000-1000-8000-00805F9B34FB"); // String for MAC address private static String address; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); //Link the buttons and textViews to respective views btnOn = (Button) findViewById(R.id.buttonOn); btnOff = (Button) findViewById(R.id.buttonOff); txtString = (TextView) findViewById(R.id.txtString); txtStringLength = (TextView) findViewById(R.id.testView1); /* sensorView0 = (TextView) findViewById(R.id.sensorView0); sensorView1 = (TextView) findViewById(R.id.sensorView1); sensorView2 = (TextView) findViewById(R.id.sensorView2); sensorView3 = (TextView) findViewById(R.id.sensorView3); bluetoothIn = new Handler() { public void handleMessage(android.os.Message msg) { if (msg.what == handlerState) { //if message is what we want String readMessage = (String) msg.obj; // msg.arg1 = bytes from connect thread recDataString.append(readMessage); //keep appending to string until ~ int endOfLineIndex = recDataString.indexOf("~"); // determine the end-of-line if (endOfLineIndex > 0) { // make sure there data before ~ String dataInPrint = recDataString.substring(0, endOfLineIndex); // extract string txtString.setText("Data Received = " + dataInPrint); int dataLength = dataInPrint.length(); //get length of data received txtStringLength.setText("String Length = " + String.valueOf(dataLength)); if (recDataString.charAt(0) == '#') //if it starts with # we know it is what we are looking for { String sensor0 = recDataString.substring(1, 5); //get sensor value from string between indices 1-5 String sensor1 = recDataString.substring(6, 10); //same again... String sensor2 = recDataString.substring(11, 15); String sensor3 = recDataString.substring(16, 20); sensorView0.setText(" Sensor 0 Voltage = " + sensor0 + "V"); //update the textviews with sensor values sensorView1.setText(" Sensor 1 Voltage = " + sensor1 + "V"); sensorView2.setText(" Sensor 2 Voltage = " + sensor2 + "V"); sensorView3.setText(" Sensor 3 Voltage = " + sensor3 + "V"); } recDataString.delete(0, recDataString.length()); //clear all string data // strIncom =" "; dataInPrint = " "; } } } }; */ btAdapter = BluetoothAdapter.getDefaultAdapter(); // get Bluetooth adapter checkBTState(); // Set up onClick listeners for buttons to send 1 or 0 to turn on/off LED btnOff.setOnClickListener(new OnClickListener() { public void onClick(View v) { mConnectedThread.write("0"); // Send "0" via Bluetooth Toast.makeText(getBaseContext(), "Turn off LED", Toast.LENGTH_SHORT).show(); } }); btnOn.setOnClickListener(new OnClickListener() { public void onClick(View v) { mConnectedThread.write("1"); // Send "1" via Bluetooth Toast.makeText(getBaseContext(), "Turn on LED", Toast.LENGTH_SHORT).show(); } }); } private BluetoothSocket createBluetoothSocket(BluetoothDevice device) throws IOException { return device.createRfcommSocketToServiceRecord(BTMODULEUUID); //creates secure outgoing connecetion with BT device using UUID } @Override public void onResume() { super.onResume(); //Get MAC address from DeviceListActivity via intent Intent intent = getIntent(); //Get the MAC address from the DeviceListActivty via EXTRA address = intent.getStringExtra(DeviceListActivity.EXTRA_DEVICE_ADDRESS); //create device and set the MAC address BluetoothDevice device = btAdapter.getRemoteDevice(address); try { btSocket = createBluetoothSocket(device); } catch (IOException e) { Toast.makeText(getBaseContext(), "Socket creation failed", Toast.LENGTH_LONG).show(); } // Establish the Bluetooth socket connection. try { btSocket.connect(); } catch (IOException e) { try { btSocket.close(); } catch (IOException e2) { //insert code to deal with this } } mConnectedThread = new ConnectedThread(btSocket); mConnectedThread.start(); //I send a character when resuming.beginning transmission to check device is connected //If it is not an exception will be thrown in the write method and finish() will be called mConnectedThread.write("x"); } @Override public void onPause() { super.onPause(); try { //Don't leave Bluetooth sockets open when leaving activity btSocket.close(); } catch (IOException e2) { //insert code to deal with this } } //Checks that the Android device Bluetooth is available and prompts to be turned on if off private void checkBTState() { if(btAdapter==null) { Toast.makeText(getBaseContext(), "Device does not support bluetooth", Toast.LENGTH_LONG).show(); } else { if (btAdapter.isEnabled()) { } else { Intent enableBtIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE); startActivityForResult(enableBtIntent, 1); } } } //create new class for connect thread private class ConnectedThread extends Thread { private final InputStream mmInStream; private final OutputStream mmOutStream; //creation of the connect thread public ConnectedThread(BluetoothSocket socket) { InputStream tmpIn = null; OutputStream tmpOut = null; try { //Create I/O streams for connection tmpIn = socket.getInputStream(); tmpOut = socket.getOutputStream(); } catch (IOException e) { } mmInStream = tmpIn; mmOutStream = tmpOut; } public void run() { byte[] buffer = new byte[256]; int bytes; // Keep looping to listen for received messages while (true) { try { bytes = mmInStream.read(buffer); //read bytes from input buffer String readMessage = new String(buffer, 0, bytes); // Send the obtained bytes to the UI Activity via handler bluetoothIn.obtainMessage(handlerState, bytes, -1, readMessage).sendToTarget(); } catch (IOException e) { break; } } } //write method public void write(String input) { byte[] msgBuffer = input.getBytes(); //converts entered String into bytes try { mmOutStream.write(msgBuffer); //write bytes over BT connection via outstream } catch (IOException e) { //if you cannot write, close the application Toast.makeText(getBaseContext(), "Connection Failure", Toast.LENGTH_LONG).show(); finish(); } } } }

activity_main.xml

<?xml version="1.0" encoding="utf-8"?> <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent" android:layout_height="match_parent" android:paddingBottom="@dimen/activity_vertical_margin" android:paddingLeft="@dimen/activity_horizontal_margin" android:paddingRight="@dimen/activity_horizontal_margin" android:paddingTop="@dimen/activity_vertical_margin" > <TextView android:id="@+id/testView1" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_above="@+id/txtString" android:text="" android:textSize="15sp" /> <TextView android:id="@+id/txtString" android:layout_width="wrap_content" android:layout_height="50dp" android:layout_alignParentBottom="true" android:text="" android:textSize="15sp" android:layout_alignParentTop="true" android:layout_toRightOf="@+id/buttonOn" android:layout_toEndOf="@+id/buttonOn" /> <Button android:id="@+id/buttonOn" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="LED ON" android:layout_above="@+id/buttonOff" android:layout_centerHorizontal="true" /> <Button android:id="@+id/buttonOff" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="LED OFF" android:layout_centerVertical="true" android:layout_alignRight="@+id/txtString" android:layout_alignEnd="@+id/txtString" />  </RelativeLayout>

device_list.xml

<?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:orientation="vertical" android:layout_width="match_parent" android:layout_height="match_parent" > <TextView android:id="@+id/title_paired_devices" android:layout_width="match_parent" android:layout_height="wrap_content" android:textAppearance="?android:attr/textAppearanceLarge" android:text="Select btSerial device from paired devices:" android:visibility="gone" android:background="#666" android:textColor="#fff" android:paddingLeft="5dp" /> <ListView android:id="@+id/paired_devices" android:layout_width="match_parent" android:layout_height="wrap_content" android:stackFromBottom="false" android:layout_weight="1" /> <TextView android:id="@+id/connecting" android:layout_width="wrap_content" android:layout_height="wrap_content" android:textAppearance="?android:attr/textAppearanceLarge" /> <TextView android:id="@+id/infoText" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="If no devices are listed please pair your device in Android settings" android:textAppearance="?android:attr/textAppearanceLarge" /> <LinearLayout android:layout_width="match_parent" android:layout_height="wrap_content" android:gravity="center"> </LinearLayout> </LinearLayout>

device_name.xml

<?xml version="1.0" encoding="utf-8"?> <TextView xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="wrap_content" android:textSize="18sp" android:padding="5dp"> </TextView>

Step 3: Final product

After struggling debugging both Arduino and Android, I successufuly controlled LED on my circuit board from my phone.

Keiichi Onishi

MAS.863 How to Make (Almost) Anything

Interface and Application Programming

Overall progress

Step 1: Programming Attiny 44 with Ardino IDE

Step 2: Programming Android App: SimpleBluetooth

Step 3: Final product