// Failed project
// --------------
// Status: I wanted to make an illusion
//         of a rotating sphere.
//         But that is not possible in this way.
//         Maybe I will fix this project someday.
//
// Illusion.ino
//
// A visual illusion of a rotating circle.
//
// Version 1, 8 June 2025, by Koepel.
//
// Public Domain
//

// The number of pins is for the number of leds per row.
// There is no limit for the number of rows, 
// but 5 is not enough and 10 seems to be too many.
#define NUM_PINS 20
#define NUM_ROWS 8
const int pins[NUM_PINS] = {0,1,2,3,4,5,6,7,8,9,10,11,12,13,A0,A1,A2,A3,A4,A5};

int index = 0;
int direction = 1;
int prevIndex = 0;

void setup() 
{
  for(int i=0; i<NUM_PINS; i++)
    pinMode(pins[i],OUTPUT);

  // Since pin 0 and 1 are also used,
  // the animation does not run well
  // when generating the diagram.
  //GenerateDiagram();
}

void loop() 
{
  // The most important part is how
  // all the leds are connected.
  float rad = float(index)/float(NUM_PINS-1) * 2 * M_PI;
  float delay1 = 150;

  // Turn off the previous led in all rows
  digitalWrite(pins[prevIndex],LOW);

  // Turn on the new led in all rows.
  digitalWrite(pins[index],HIGH);

  delay((unsigned long)delay1);

  prevIndex = index;

  index += direction;
  if(index == (NUM_PINS-1) || index == 0)
    direction = -direction;
}

// The function GenerateDiagram() can be used to generate
// the complete diagram.json file for Wokwi.
// To use it, call it from the setup() function, and the
// serial output can be copied into the diagram.json file.
void GenerateDiagram()
{
  // Design constants.
  float radius = 500; // the radius of the full circle
  float distance = radius * 2.0 / float(NUM_PINS); // distance between leds

  Serial.begin(115200);

  Serial.print( "{\n");
  Serial.print( "  \"version\": 1,\n");
  Serial.print( "  \"author\": \"Generated\",\n");
  Serial.print( "  \"editor\": \"wokwi\",\n");
  Serial.print( "  \"parts\": [\n");

  Serial.print( "    {\n");
  Serial.print( "      \"type\": \"wokwi-arduino-uno\",\n");
  Serial.print( "      \"id\": \"uno\",\n");
  Serial.print( "      \"top\": 300,\n");
  Serial.print( "      \"left\": 400,\n");
  Serial.print( "      \"attrs\": {}\n");
  Serial.print( "    },\n");

  int i = 0;
  for(int row=0; row<NUM_ROWS; row++)
  {
    float rad = M_PI * float(row) / float(NUM_ROWS); 
    for(int led=0; led<NUM_PINS; led++)
    {
      float l = float(led) - float(NUM_PINS-1)/2.0;
      float left = l*distance*cos(rad);
      float top = l*distance*sin(rad);

      Serial.print( "    {\n");
      Serial.print( "      \"type\": \"wokwi-led\",\n");
      Serial.print( "      \"id\": \"led");
      Serial.print( i);
      Serial.print( "\",\n");
      Serial.print( "      \"top\": ");
      Serial.print( top);
      Serial.print( ",\n");
      Serial.print( "      \"left\": ");
      Serial.print( left);
      Serial.print( ",\n");
      Serial.print( "      \"attrs\": { \"color\": \"Red\" }\n");

      Serial.print( "    }");
      if( i < (NUM_ROWS*NUM_PINS)-1)
        Serial.print( ",");
      Serial.print( "\n");

      i++;
    }
  } 

  Serial.print( "  ],\n");
  Serial.print( "  \"connections\": [\n");

  i=0;
  for(int row=0; row<NUM_ROWS; row++)
  {
    for(int led=0; led<NUM_PINS; led++)
    {
      // 'j' should be calculated in a different way.
      int j = (row + led)%NUM_PINS;

      Serial.print( "    [ \"led");
      Serial.print( i);
      Serial.print( ":A\", \"uno:");
      if(pins[j] < A0)
      {
        Serial.print(j);
      }
      else
      {
        Serial.print("A");
        Serial.print(j-A0);
      }
      Serial.print( "\", \"\", []],\n");

      Serial.print( "    [ \"led");
      Serial.print( i);
      Serial.print( ":C\", \"uno:GND.2\", \"\", []]");

      if( i < (NUM_ROWS*NUM_PINS)-1)
        Serial.print( ",");
      Serial.print("\n");

      i++;
    }
  }

  Serial.print( "  ]\n");
  Serial.print( "}\n");
}