12v LED lights stay on

Other Hardware LEDs and Multiplexing
1

Hello,
I am making some flashing 12V LED lights with my ardiuno uno and a bluetooth module. What i have working is when i press "1" on my bluetooth terminal the lights start flashing, but when i press "0" they don't turn off, they just stay completely on no flashing. Also when I don't apply power to the Uno the LEDs stay on but dim. Can someone please point me in the right direction on what I have done wrong?
My goal in general what im wanting to do with this project is when i turn on the arduino the lights are off. When I press "1" i want them to turn on and flash. Then I want them to stay on until i press "0" and have all the lights turned off. For all this to work i'm just working step by step so I can learn this sketching a bit more.
My code:

char INBYTE;
 
void setup() 
{ 
  Serial.begin(9600); 
  pinMode(10, OUTPUT);
pinMode(7, OUTPUT);
 
} 
 

void loop() 
{ 
  Serial.println("Press 1 to turn lights on or 0 to turn lights off:");  // lights on or off 
  while (!Serial.available());   // stay here so long as COM port is empty   
  INBYTE = Serial.read();        // read next available byte                                  
  if( INBYTE == '1' ) {

digitalWrite(10, HIGH);
delay(100); // When value is changed lights change speed

digitalWrite(10, LOW);
delay(50);

digitalWrite(10, HIGH);
delay(50);

digitalWrite(10, LOW);
delay(100);

digitalWrite(10, HIGH);
delay(50);

digitalWrite(10, LOW);
delay(0);

digitalWrite(7, HIGH);
delay(100);

digitalWrite(7, LOW);
delay(50);

digitalWrite(7, HIGH);
delay(50);

digitalWrite(7, LOW);
delay(100);

digitalWrite(7, HIGH);
delay(50);

digitalWrite(7, LOW);
delay(0);
}                 // if it's a 1 lights turn on and flash on the given speed
  if( INBYTE == '0' ){
  digitalWrite(10,LOW);
 digitalWrite(7, LOW);} // if it's a 0 lights turn off  
  }

I have also added how I have wired my lights.
Many thanks in advance.

Flashing lights.png
Flashing lights.png869×685 173 KB

2

Is this exact circuit ? How you not managed to burn your Arduino with this circuit ?

3

Yes this is my exact circuit. I have no idea. It's not even getting hot. I study mechanical engineering so i'm not very good with electronics. Did i not wire it correct?

4

You need current limiter resistors, and proper transistors. May your leds have resistors built-in may not. digitalWriting LOW to pin causes led to turn on, because when digitalPin becomes LOW current sinks to pin. This is about your circuit setup.

5

Here's a safe LED circuit (it shows 5V on the LED, but 12V is safe to use too, after adjusting the LED resistor value):

http://www.sqlskills.com/blogs/paulselec/post/arduino-figuring-out-transistors-and-associated-resistors.aspx