tiny_LS_cp_short_buffer

/*
  Based on https://github.com/maltesemanTS1/Charlieplexing-the-Arduino
  http://arduino.cc/en/Tutorial/BitMask
*/


int16_t shifter = 0;
uint8_t shifter_factor = 8; // also speed influence
bool toggle = true;
const uint8_t max_leds = 20;
uint8_t pwm_value;

uint8_t pwm_values[5] = { 127, 63, 32, 15, 1 };

void setup()
{
}

void loop() {
  short_buffer_write();
}

void short_buffer_write()
{
  for (int i= -5; i<25; i++)
  {
    for (uint8_t p = 0; p < 127; p++)
    {
      for (int j=0; j<5; j++)
      {
        if (
            i+j >= 0 &&
            i+j < 20
        ) {
          
          if (toggle) pwm_value = pwm_values[4-j];
          else pwm_value = pwm_values[j];
          
          if (p < pwm_value)
          {
            if (toggle) charlie(i+j);
            else charlie(max_leds - i + j -1); // -1 to get to zero
           // delayMicroseconds(10);
          }
        }
      }
    }
  }

  charlie(-1);
  toggle = !toggle;
  if (toggle) delay(2000);
}


void charlie_combo(uint8_t a, uint8_t b)
{
  // output
  DDRB |= (1 << a);
  // output
  DDRB |= (1 << b);
  // high
  PORTB |= (1<<a);
  // low
  PORTB &= ~(1<<b);
}

void charlie (uint8_t var)
{
  // DDRB |= (0x1F);
  DDRB &= ~(0x1F);

  PORTB &= ~(0x1F);

  switch (var) {
    case  0: charlie_combo(0, 1); break;
    case  1: charlie_combo(1, 0); break;
    case  2: charlie_combo(0, 2); break;
    case  3: charlie_combo(2, 0); break;
    case  4: charlie_combo(0, 3); break;
    case  5: charlie_combo(3, 0); break;
    case  6: charlie_combo(0, 4); break;
    case  7: charlie_combo(4, 0); break;
    case  8: charlie_combo(1, 2); break;
    case  9: charlie_combo(2, 1); break;
    case 10: charlie_combo(1, 3); break;
    case 11: charlie_combo(3, 1); break;
    case 12: charlie_combo(1, 4); break;
    case 13: charlie_combo(4, 1); break;
    case 14: charlie_combo(2, 3); break;
    case 15: charlie_combo(3, 2); break;
    case 16: charlie_combo(2, 4); break;
    case 17: charlie_combo(4, 2); break;
    case 18: charlie_combo(3, 4); break;
    case 19: charlie_combo(4, 3); break;

    default: ;
  }
}