MM5451N LED Driver

Forum 2005-2010 (read only) Hardware Interfacing
1

Has anyone used this LED Driver before? It looks like a good way to output to 30+ LEDs from a couple of pins.

2

server is down.
can you say a few details?
pwm?

3

Yeah someone already made a shield with that a while back.

http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1235795499/0

It's just a shift register, really.

4

Hello,

Is it possible to use the above example with an MM5450BN chip?

http://www.datasheetcatalog.org/datasheet2/9/0o13pk69a9pykerrd82w018d42py.pdf

I wired it all together based on http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1155067315 and ran the code listed on arduino website, not working!

Im trying it with just 1 LED right now and from what I read about 5450, it does not need a resistor for the LEDs (I tried it both ways though).

To check the LED itself I ran it with "Blink" example through pin13 and it works - so the voltage/ground part is right at least.

With the slight datasheet differences between the chips, can someone verify the following.. ?

4794 5450
STR = Brightness control ?
CP = Clock In ?
EO = Data Enable ?

int data = 9;
int strob = 8;
int clock = 10;
int oe = 11;
int count = 0;
int dato = 0;

void setup()
{
  Serial.begin(9600);
  pinMode(data, OUTPUT);
  pinMode(clock, OUTPUT);
  pinMode(strob, OUTPUT);
  pinMode(oe, OUTPUT);
}

void PulseClock(void) {
    digitalWrite(clock, LOW);
    delayMicroseconds(20);
    digitalWrite(clock, HIGH);
    delayMicroseconds(50);
    digitalWrite(clock, LOW);
}

void loop()
{
   dato = 5;
   for (count = 0; count < 8; count++) {
    digitalWrite(data, dato & 01);
    Serial.write((dato & 01) + 48);
    dato>>=1;
    if (count == 7){
    digitalWrite(oe, LOW);
    digitalWrite(strob, HIGH);

    }
    PulseClock();
     digitalWrite(oe, HIGH);
 }

  delayMicroseconds(20);
  digitalWrite(strob, LOW);
  delay(100);


  Serial.write(10);
  Serial.write(13);
 delay(100);                  // waits for a moment
}

Any advice for the newbie?