Bit, Byte, and Loop issue.

Forum 2005-2010 (read only) Software Syntax & Programs
1

I'm slightly modifying a script I found on the web regarding running a 7 segment display. The original script was set to run on pins 0-6 but I need to retain serial comms for my project.

I've stepped through the script in my head and on paper a few times and can't figure out why I'm having this issue.

Any number below 4 is displaying completely wrong. I've double checked that the bytes are set up correctly for my CA display. I'm at a loss.

Here's the code. Any comments, quips, or suggestions are greatly appreciated. I'm trying to learn to be concise and practical with my coding.

             //     0    1   2   3   4   5  6    7  8   9
byte numDef[10] = {64, 121, 36, 48, 25, 18, 2, 120, 0, 24};

void setup() 
{

  for (int i = 2; i < 9; i++)
  {
    pinMode(i, OUTPUT);
  }
  
  clearDisplay();
  
}

void loop() 
{

  for (int i = 0; i < 10; i++)
  {
    writeDisplay(i);
    delay(500);
    clearDisplay();
  }
  
}

void writeDisplay(int num)
{
  byte segments = numDef[num];
  for (int i = 2; i < 9; i++)
  {
    int b = i - 2;
    int bitVal = bitRead(segments, b);
    digitalWrite(i, bitVal);
  }
}

void clearDisplay()
{
  for (int i = 2; i < 9; i++)
  {
    digitalWrite(i, HIGH);
  }
}