Port manipulation in Arduino using byte value

Question

I'm trying to write PORTB and PORTD in ATmega328P using byte system like this,

 // PD7 PD6 PD5 PD4 PD3 PD2 PD1 PD0
 // N N N N N U U U
 // 7 6 5 4 3 2 1 0
 //======================================
 // PB7 PB6 PB5 PB4 PB3 PB2 PB1 PB0
 // X X 1 1 1 1 1 1
 // C C 13 12 11 10 9 8
 //======================================
 //C-Crystal Pins/U-Un used/N-Used/X-unknown value
 byte pins[] = {3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13};
 //uint16_t style1=1365; //10101010101
 //uint16_t style2=682; //01010101010
 void setup() {
 for (int i = 0; i < 11; i++) {
 pinMode(pins[i],OUTPUT);
 PORTD=B00000000;
 PORTB=B00000000;
 }
 }
 void loop() {
 PORTD=B10101000;
 PORTB=B00101010;
 delay(1000);
 PORTD=B01010000;
 PORTB=B00010101;
 }

According to this , Port value should be swapped. But, It's still remaining given value of the code before delay()

What is the problem in this code?

Answer 1

What is the problem in this code?

No problem, it does change the bits of port D and B from 0B10101000 and 0B00101010 to 0B01010000 and 0B00010101 respectively.

However, microseconds later loop() runs again and changes them back to 0B10101000 and 0B00101010 for a full second.

To better see what's happening, add a second delay(1000); statement, placing it just before the closing brace.

• user_fs10: Ops,,,I really know about that.But,I have forgot that.,Im very mad. Thank you.