I'm trying to set up a system where an android app connects to Arduino via Bluetooth and tells it to either turn on or off its LED. I've looked through a lot of pages and source code and saw many people did it as I did but somehow my code isn't working and I cannot determine why.
Here's the entirety of my Arduino code, really simple and short.
#include <SoftwareSerial.h>
SoftwareSerial Blue(0,1); // rx tx
int LED = 13; // Led connected
char data;
char state = 0;
void setup()
{
pinMode(LED, OUTPUT);
digitalWrite(LED, LOW);
Serial.begin(9600);
Blue.begin(9600);
}
void loop()
{
while(Blue.available()==0);
if(Blue.available()>0){ // read from android via bluetooth
data = Blue.read();
Serial.println(data);
}
if (data == '1') // If data is 1, turn ON the LED
{
digitalWrite(LED,HIGH);
Serial.println("LED ON ");
}
if( data == '2') // if data is 2, turn OFF the LED
{
digitalWrite(LED,LOW);
Serial.println("LED OFF");
}
}
And here's a snippet of my android code that sends data to Arduino to control LED
switchLight.setOnClickListener(new View.OnClickListener() { // button that will switch LED on and off
@Override
public void onClick(View v) {
Log.i("[BLUETOOTH]", "Attempting to send data");
if (mmSocket.isConnected() && btt != null) { //if we have connection to the bluetoothmodule
if (!lightflag) {
try{
mmSocket.getOutputStream().write("1".toString().getBytes());
showToast("on");
}catch (IOException e) {
showToast("Error");
// TODO Auto-generated catch block
e.printStackTrace();
}
//btt.write(sendtxt.getBytes());
lightflag = true;
} else {
try{
mmSocket.getOutputStream().write("2".toString().getBytes());
showToast("off");
}catch (IOException e) {
showToast("Error");
// TODO Auto-generated catch block
e.printStackTrace();
}
//btt.write(sendtxt.getBytes());
lightflag = false;
}
}
else {
Toast.makeText(MainActivity.this, "Something went wrong", Toast.LENGTH_LONG).show();
}
}
});
This is the part of the code that connects to Arduino Bluetooth module. Again, fairly simple stuff and its only purpose are to connect to the module.
BluetoothAdapter bta; //bluetooth stuff
BluetoothSocket mmSocket; //bluetooth stuff
BluetoothDevice mmDevice; //bluetooth stuff
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Log.i("[BLUETOOTH]", "Creating listeners");
final TextView response = findViewById(R.id.response);
Button switchLight = findViewById(R.id.switchlight);
Button connectBT = findViewById(R.id.connectBT);
connectBT.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
BluetoothSocket tmp = null;
mmDevice = bta.getRemoteDevice(MODULE_MAC);
Log.i("[BLUETOOTH]", "Attempting to send data");
try {
tmp = mmDevice.createRfcommSocketToServiceRecord(MY_UUID);
mmSocket = tmp;
mmSocket.connect();
Log.i("[BLUETOOTH]","Connected to: "+mmDevice.getName());
showToast("Connected to: " + mmDevice.getName());
}catch(IOException e){
try {mmSocket.close();
}catch(IOException c){return;}
}
}
});
When I connect my android to the Arduino and track the serial monitor on Arduino IDE, instead of reading either 1 or 2, it reads something that looks like this:
This is produced using the Serial. println function in my Arduino code and I'm pretty sure it should display 1 or 2 but as you can see it does not. I've tried multiple workarounds like declaring it as int or char etc. If you can pinpoint any issue I'd much appreciate it.