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Arduino
Arduino Forum Arduino led on and off program using hc05 bluetooth module doesn't work.
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Forum Thread Details
  • State Not Answered
  • Replies 3 replies
  • Subscribers 392 subscribers
  • Views 1193 views
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  • bluetooth
  • arduino uno
  • hc05
  • hc-05
  • arduino
Related

Arduino led on and off program using hc05 bluetooth module doesn't work.

Former Member
Former Member over 9 years ago

I have tried to connect my arduino with hc-05, and run a simple 'LED on and off' program. When I disconnected the rx and tx pins and tried sending the commands using serial monitor in arduino, and it worked perfectly alright. But when I connected the rx and tx pins of hc-05 bluetooth module, and used the Bluetooth terminal app from playstore to send and recieve commands, whatever I send doesn't get recieved the same, instead I get weird characters on my serial monitor. Someone please help me solve this. I have included the arduino code and the screen shots of the serial monitor and the app.

 

char junk;
String inputString="";

void setup()
{
Serial.begin(9600);
pinMode(13, OUTPUT);
}

void loop()
{
  if(Serial.available()){
  while(Serial.available())
  {
  char inChar = (char)Serial.read();
  inputString += inChar;
  }
  Serial.println(inputString);
  while (Serial.available() > 0) 
  { junk = Serial.read() ; }
  if(inputString == "a"){
  digitalWrite(13, HIGH); 
  }else if(inputString == "b"){ 
  digitalWrite(13, LOW);
  }
  inputString = "";
  }
}

 

Serial Monitor

Bluetooth terminal App

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  • gihu
    0 gihu over 9 years ago

    Hi,

     

    It seems like if Arduino and HC05 were configured with different baudrate.

    Check both UART work at the same baudrate, with the same parity, stopbits...

     

    Hope that helps

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  • neilk
    0 neilk over 9 years ago

    hi venkatpraveenx

     

    Your Arduino and HC05 appear to be on different baud rates. Look at the configuration of the HC05 - it should be 9600

     

    Neil

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  • clem57
    0 clem57 over 9 years ago

    Check if the terminal program in Arduino is using character return and line feed or not. If ob, turn off.

    Clem

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