Blink Code ATmega2560 not working in Proteus

Question

I am running a simple blink program in an ATmega2560 with external 8MHz crystal. When I run it in Proteus, the LEDs do not blink. Refer to my files below.

This is the simple blink code. I just add prescaler bits to verify its functionality.

    void setup() {
      noInterrupts();
      CLKPR = 0x80;                           /*Enabling the clock prescaler function*/
      CLKPR = 0x00;                           /*Setting the prescaler to div by 1*/
      interrupts();
    
      pinMode(13, OUTPUT);
    }
    
    void loop() {
      digitalWrite(13, HIGH);   // turn the LED on (HIGH is the voltage level)
      delay(500);                       // wait for a second
      digitalWrite(13, LOW);    // turn the LED off by making the voltage LOW
      delay(500);                       // wait for a second
    }

I correctly choose the ATmega2560 with external 8MHz.

And this is my circuit in Proteus: (Removing the VDD in reset, AVCC, AREF doesn't help.)

And I set the fuse bits to work with external crystal:

I don't know where I went wrong. Please help.

Answer 1

You have your LED connected to the wrong pin.

The Arduino mapping does not follow physical pin numbers.

Either change your code to use Digital Pin 16 (which is where you are currently connected), or move your LED over to physical pin 26 (which is Digital Pin 13).

I also don't see Pin 99 (GND) connected anywhere on your schematic... And it is also missing a number of VCC connections and GND pins. I'm not familiar with Proteus so I'm not sure why these pins are missing, but it seems like that would be an important part to have.