DL2416 Test

Found some DL2416’s in storage a looong time ago, and decided to put them to use.

Unfortunately I dont have a schematic drawn up, but the connection is very simple. Most of the data lines for the displays are in parallel (power, ground, address, data, clear, and blank) and the rest are controlled by the Arduino (write) which controls the /CE decoder. The only additional hardware I used is a 74LS138 decoder, with outputs 0-4 tied to the /CE lines of each respective display.

The code is very simple, you just have to feed the display ASCII and it displays it:

// DL2416 Test v1.0 by J Skoba aka SpikedCola

int CLR = 12;
int A0 = 9;
int A1 = 10;
int WR = 8;
int BL = 13;
int EN = 11;

char stringToShow[] = "THIS SPACE 4 RENT!!!";

void setup() 
{
  pinMode(CLR, OUTPUT);
  pinMode(A0, OUTPUT);
  pinMode(A1, OUTPUT);
  pinMode(WR, OUTPUT);
  pinMode(BL, OUTPUT);
  pinMode(EN, OUTPUT);
  
  DDRD = 0xFF;
  DDRC = 0xFF;
  PORTC = 0x00;
  PORTD = 0x00;

  digitalWrite(CLR, HIGH);
  digitalWrite(BL, HIGH);

  for (int a = 0; a < (sizeof(stringToShow) - 1); a++)
  {
    printLetter(stringToShow[a], a / 4, a % 4);
  }
}

void loop() 
{
}

void printLetter(byte text, int displayNumber, int digit)
{
  PORTC = displayNumber; // set decoder to specific dl2416t

  digitalWrite(EN, HIGH); // turn decoder on

  digitalWrite(A0, bitRead(3 - digit, 0));
  digitalWrite(A1, bitRead(3 - digit, 1));

  PORTD = text;

  digitalWrite(WR, LOW); // latch display
  digitalWrite(WR, HIGH);
  digitalWrite(EN, LOW); // turn decoder off
}

Nothing too special, but hopefully the code will help someone out. Id still like to add scrolling and the ability to wrap around new text while still scrolling old text, but this is outside my programming skill level.

That's a lot of jumper wires! You must be very patient.

I really like the retro look of the DL2416's. They're like the '70s equivalent of Nixie-tube nostalgia.

Jon Freetronics: www.freetronics.com Practical Arduino: www.practicalarduino.com

I really like the retro look of the DL2416's. They're like the '70s equivalent of Nixie-tube nostalgia.

Yeah, never seen those before but they look very cool!

After hooking up one and seeing the font of the characters, that retro look is exactly what kept me going through that mess of wires =P thanks guys!