Counter 0-9 with 7 segments display and Arduino Uno.jpg

In this example I propose a simple simulation with Tinkercad of a circuit that creates a counter from 0 to 9 with a 7-segment display, programmed using Arduino Uno. The display is of the common cathode type.

The sketch that I propose to you is really working. This is the link: It is based on a look-up table made with an array where I have coded the digits of the numbers to be shown on the display.
I used port registers based programming and I choosed the ATMega 328 pin group called port D which is 8 bit and is convenient for managing an LED display. Here you can find information about Arduino port registers:

It is important that when you load the sketch in the Arduino FLASH memory, you momentarily disconnect pins 0 and 1, because they are used by the USB as serial TX and RX, otherwise the loading fails.

This is the sketch:

byte numero [10]={B00111111, B00000110, B01011011, B01001111, B01100110, B01101101, B01111101, B00000111, B01111111, B01101111};

int i=0;

void setup()
   DDRD = B11111111;

void loop()
   PORTD = numero[i];
   if (i>9)