Android and Arduino both receiving strange values via Bluetooth

问题

I am using BluetoothChat code on the Android side to send an ON/OFF signal (I am sending 110, 119 or other cases as defined below) to the Arduino UNO using the chat box, but when I display the received value, it shows strange values in the Arduino Serial monitor, that is, 255, 254, 250 or 245 and replies with strange values on the Android side too.

but suprisingly only single condition among 110, 119, etc gets true when i send these commands from android and no other instruction/LED gets properly executed/turned ON/off.

Can any one help me figure out the problem? Below is my arduino code.

int data; 
String message; 

void setup () 
{ 
Serial.begin (57600); 

pinMode (6, OUTPUT); 
pinMode (7, OUTPUT); 
pinMode (8, OUTPUT); 
pinMode (9, OUTPUT); 
pinMode (10, OUTPUT); 

digitalWrite(6, LOW); // off LED 1 at pin6 
digitalWrite(7, LOW); // off LED 2 at pin7 
digitalWrite(8, LOW); // off LED 3 at pin8 
digitalWrite(9, LOW); // off LED 4 at pin9 
digitalWrite(10, LOW); // off LED 5 at pin10 
}

void loop () { 
int i=0; 
if (Serial.available()>0) 
{ 
int data= Serial.read(); 

Serial.println (" Received data: "); 
Serial.println (data); 

if (data==110) //q 
{ 
digitalWrite(6, HIGH); // turn on LED 1 at pin6 
message = "LED 1 On"; 
Serial.println (message); 

} 
if (data==102) // a 
{ 
digitalWrite(6, LOW); // off LED 1 at pin6 
message = "LED 1 Off"; 
Serial.println (message); 
} 

if (data==96) //c 
{ 
digitalWrite(7, HIGH); //on LED 2 
message = "LED 2 On"; 
Serial.println (message); 
} 

if (data==115) //d 
{ 
digitalWrite(7, LOW); // off LED 2 
message = "LED 2 Off"; 
Serial.println (message); 
} 

if (data==111) //e 
{ 
digitalWrite(8, HIGH); //on LED 3 
message = "LED 3 On"; 
Serial.println (message); 
} 

if (data==97)// f 
{ 
digitalWrite(8, LOW); //sets the LED 3 
message = "LED 3 Off"; 
Serial.println (message); 
} 

if (data==107) //g 
{ 
digitalWrite(9, HIGH); //turn on LED 4 
message = "LED 4 On"; 
Serial.println (message); 
} 

if (data==120)//h 
{ 
digitalWrite(9, LOW); //sets the LED 4 
message = "LED 4 Off"; 
Serial.println (message); 
} 


if (data==99) //i 
{ 
digitalWrite(10, HIGH); //sets the LED 5 
message = "L5 high"; 
Serial.println (message); 
} 

if (data==104) //j 
{ 
digitalWrite(10, LOW); //sets the LED 5 
message = "LED 5 Off"; 
Serial.println (message); 
} 

if (data==112) //y 
{ 
digitalWrite(6, HIGH); // turn on ALL LEDs 
digitalWrite(7, HIGH); 
digitalWrite(8, HIGH); 
digitalWrite(9, HIGH); 
digitalWrite(10, HIGH); 
message = "ALL LEDs ON"; 
Serial.println (message); 
} 


if (data==122)//z 
{ 
digitalWrite(6, LOW); //Turn off all LEDs 
digitalWrite(7, LOW); 
digitalWrite(8, LOW); 
digitalWrite(9, LOW); 
digitalWrite(10, LOW); 
Serial.println ("ALL LEDs OFF"); 
} 

else 
{ 
digitalWrite(13, HIGH); //sets the LED 5 
delay(3000); //3sec 
digitalWrite(13, LOW); 
delay(3000); 
Serial.println (" else case executed "); 

} ////end of else 

}
data=0;
}

回答1:

Try char data = Serial.read();

And show Java code for Android.

See 100% work code for Bluetooth Arduino&Android

回答2:

If you are using Arduino Uno, then you can't use the serial monitor to print values, if you are already using serial to communicate to Bluetooth, since it has only one serial port.

You have to use the Software serial library or use Arduino Mega, which has 4 serial ports.

来源：https://stackoverflow.com/questions/12718301/android-and-arduino-both-receiving-strange-values-via-bluetooth