Hello instructables, i ran the code below in the arduino uno, (4 motors, 2 L293D driver chips) void loop() { digitalWrite(motor_pin1,LOW); //forward back digitalWrite(motor_pin2,HIGH); digitalWrite(motor_pin3,HIGH); digitalWrite(motor_pin4,LOW); digitalWrite(motor_pin5,LOW); //forward front digitalWrite(motor_pin6,HIGH); digitalWrite(motor_pin7,HIGH); digitalWrite(motor_pin8,LOW); delay (5000); digitalWrite(motor_pin1,HIGH); //turn right digitalWrite(motor_pin2,LOW); digitalWrite(motor_pin3,HIGH); digitalWrite(motor_pin4,LOW); digitalWrite(motor_pin5,HIGH); //turn right digitalWrite(motor_pin6,LOW); digitalWrite(motor_pin7,HIGH); digitalWrite(motor_pin8,LOW); delay (2000); digitalWrite(motor_pin1,LOW); //stop moving digitalWrite(motor_pin2,LOW); digitalWrite(motor_pin3,LOW); digitalWrite(motor_pin4,LOW); digitalWrite(motor_pin5,LOW); //stop moving digitalWrite(motor_pin6,LOW); digitalWrite(motor_pin7,LOW); digitalWrite(motor_pin8,LOW); while (1); } by right, the motors should stop infinitely due to the while(1), but this is what happens instead : initial : loop1 12 secs later : loop 2 1 sec later : loop 3 1 sec later : loop 4 .... why is it running more than once?