Does nobody kn'ow I write code to the M5482 driver

Forum 2005-2010 (read only) Hardware Interfacing
1

How do I write the C-code to manage this led display driver?

www.datasheetcatalog.org/datasheet/SGSThomsonMicroelectronics/mXqqv.pdf

page 3-4 explains the 35bit data transmisson it needs how do i code that???

But how do I make it display numbers 0-9 ????

thanks

Here is the code i use for making it blink in strange patterns:

/* Shift Out Data
* --------------
*
* Shows a byte, stored in "dato" on a set of 8 LEDs
*
* (copyleft) 2005 K3, Malmo University
* @author: David Cuartielles, Marcus Hannerstig
* @hardware: David Cuartielles, Marcos Yarza
* @project: made for SMEE - Experiential Vehicles
*/


int data = 3;
int strob = 8;
int clock = 4;
int oe = 11;
int count = 0;
int dato = 0;

void setup()
{
beginSerial(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 = 254;
 for (count = 0; count < 8; count++) {
  digitalWrite(data, dato & 01);
  //serialWrite((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);


serialWrite(10);
serialWrite(13);
delay(100);                  // waits for a moment
}
2

page 3-4 explains the 35bit data transmisson it needs how do i code that?

Treat it just like a shift register. See the shift register examples in the playground.

But how do I make it display numbers 0-9

Each bit of data you send it controls one segment of two seven segment displays. So simply generate an array with the segment patterns in it and index it to the number you want to display. Again look it up in the playground.

When you post code surround it in {code} .... {/code} only use square brackets.

3

I think i need more help than that, I don't find any shift register examples
:slight_smile: Im really not good in writing

 could you send a good example you think i can use for ripping some of the code from, please.  

[quote]
FUNCTIONAL DESCRIPTION
The M5482 uses the M5451 die which is packaged
to operate 2-digit alphanumeric displays with minimal
interface with the display and the data source.
Serial data transfer from the data source to the
display driver is accomplished with 2 signals, serial
data and clock. Using a format of a leading "1"
followed by the 35 data bits allows data transfer
without an additional load signal.
The 35 data bits are latched after the 36th bit is
complete, thus providing non-multiplexed, direct
drive to the display. Outputs change only if the
serial data bits differ from the previous time. Display
brightness is determined by control of the output
current for LED displays. A 1nF capacitor should be
connected to brightness control, Pin 9, to prevent
possible oscillations.
A block diagram is shown in Figure 1. The output
current is typically 20 times greater than the current
into Pin 9, which is set by an external variable
resistor.
There is an internal limiting resistor of 400W nominal
value.
Figure 2 shows the input data format. A start bit of
logical "1" precedes the 35 bits of data. At the 36th
clock a LOAD signal is generated synchronously
with the high state of the clock, which loads the 35
bits of the shift registers into the latches. 
At the low state of the clock a RESET signal is
generated which clears all the shift registers for the
next set of data. The shift registers are static master
slave configurations. There is no clear for the master
portion of the first shift register, thus allowing
continuous operation.
There must be a complete set of 36 clocks or the
shift registers will not clear.
When power is first applied to the chip an internal
power ON reset signal is generated which resets
all registers and all latches. The START bit and the
first clock return the chip to its normal operation.
Figure 3 shows the timing relationships between
Data and Clock.
A maximum clock frequency of 0.5 MHz is assumed.
Figure 4 shows the Output Data Format for the
M5482. Because it uses only 15 of the possible 35
outputs, 20 of the bits are "Don't Cares".
For applications where a lesser number of outputs
are used it is possible to either increase the currentper output or operate the part at higher than 1V
VOUT.
The following equation can be used for calculations.
Tj º [(VOUT)(ILED)(no.of segments) + VDD . 7 mA]
(80 °C/W) + Tamb
where :
Tj = junction temperature (150 °C max)
VOUT = the voltage at the LED driver outputs
ILED = the LED current
80 °C/W = thermal coefficient of the package
Tamb = ambient temperature[/quote]
4

I don't find any shift register examples

you don't look too good.

http://www.arduino.cc/playground/Code/ShiftRegSN74HC165N

5

Driving M5451 from Arduino: effluviaofascatteredmind.blogspot.com