Using a geometric series to control many LEDs

[johnwasser]

@Arduino-x

Code for Opto_Receive:

const byte InputPins[6] = {2, 3, 4, 5, 6, 7};
//index is.................0, 1, 2, 3, 4, 5

uint16_t DataMask_Input;
String Previous_Input;
String Received_Input;

uint16_t ReadInputs() {
    uint16_t DataMask_Input = 0;
    for (int i = 5; i >= 0; --i)
    {
      DataMask_Input <<= 1;
      DataMask_Input |= (digitalRead(InputPins[i]) == LOW); //LOW to reflect the logic inversion with photocouplers
    }
    return DataMask_Input;
}

void setup() {
  for (int i = 0; i <= 5; i++)
    pinMode(InputPins[i], INPUT_PULLUP);
  
  Serial.begin(9600);
}

void loop() {
  Previous_Input = Received_Input;
  Received_Input = ReadInputs();
  delay(20);

  if (Received_Input != '0' && Received_Input !=Previous_Input) {
  Serial.print("Binary Received = ");
  Serial.print(ReadInputs(), BIN);
  delay(20);
  Serial.println(" Integer Received = " + Received_Input);
  }
}

It looks OK to me. Can you show the Serial Monitor output on the receive side?