I tried the blink program with no delay, ( assuming that this is as quick and simple as it can get ) and the switched output was 8uS period, and with DigitalWriteFast it was 860 nS or 1.16 Mhz,  so I guess I will shelve this idea for now.

I had :-

int ledPin =  13;    // LED connected to digital pin 13
void setup()   {                
   pinMode(ledPin, OUTPUT);    
}
void loop()                    
{
  digitalWriteFast(13, HIGH);   // set the LED on

  digitalWriteFast(13, LOW);    // set the LED off

}

Thanks Senso
I will check that out and see if it can handle the vga

Sorry I should have mentioned its vga,  I have the sync extracted , I use an exclusive or gate for auto detecting the polarity , the proto is working fine.
I wonder if the sync coming so soon after the last bit of data would be a problem ( with the graphic block being on the right hand side ) ?

Its basically from a PC, I am superimposing text or shapes in the top RH corner, thats why I wondered how fast the ardiuno would run.

The guy who normally writes the software ( PIC )  for my projects reckoned it would be too fast for a micro, which is why I built the first one from 74HC chips, but having now taken an interest in programming , and seeing some of the projects out there, it made me wonder ?

that promethues thing shows it can be done, but that is way out of my league ( I am a newbie to programming and Arduino, with 3 weeks experience, and one project finished to my name )

Hi cr0sh
The TV out looks interesting but I am running at 1024 x 768 x 60 Hz, but I can afford to lose some resolution if needed .....

Thats sounding good,  I only want to put some block type text or shapes in the top right hand corner of the screen.

Every n number of lines I would want to change the data ( n representing the number of lines to make the height of the block )

So perhaps I can change the data ( the binary number ) during the first half of the scan,  and then send the data?

If I can't make  the number changing during the delay, perhaps have one long number of permanent zeros, then the variable data ?

My present prototype has a handful of 74HC chips so getting it down to one chip would be very rewarding.   ( Each block at the moment is 1/80th of a line wide. )

I am not worried about gray scale, just black squares, and the horizontal sync from the monitor must start the output of the data stream.

How fast can a pin designated as an output, be switched on and off repeatedly, like the "blink" sketch without any delays ?

John

thanks Paul, I will give it a try

Hi

I am playing around with an idea to send a data stream ( large binary number ) to the video signal of a monitor to generate a pattern.

It would need to be synchronised to the line pulse from the monitor.

Would a Serial.println(number in binary);  send an output data stream to any chosen pin of the chip ?  ( without needing any handshaking? )

If so, how fast can the data stream be from a Duemilanove?

John

Thanks

I will try that over the weekend,  at the moment it is all running fine with

  if (track==1) {playcomplete("tillnum1.wav");}
else;
   if (track==2) {playcomplete("tillnum2.wav");}
else;

and so on,  but I will try the others so I can get used to the options.

I am struggling with the char array a bit, but the example I have been borrowing from for testing the waveshield uses switch/break statements, would this work for my example with 9 tracks ( I have already established the track number requested   "track" )

 switch (track()) {
    case 1:
      playcomplete("tillnum1.wav");
      break;
    case 2:
      playcomplete("tillnum2.wav");
      break;
    case 3:
      playcomplete("tillnum3.wav");
      break;
    case 4:
      playcomplete("tillnum4.wav");
      break;
    case 5:
      playcomplete("tillnum5.wav");
      break;
    case 6:
      playcomplete("tillnum6.wav");
     case 7:
      playcomplete("tillnum7.wav");
      break;
    case 8:
      playcomplete("tillnum8.wav");
      break;
    case 9:
      playcomplete("tillnum9.wav");

Thanks PaulS,
I will try that array, I have got the waveshield running with one of the waveHC examples with 6 switches.

While it doesn't queue, it doesn't interrupt the current message which will do for now, till I work on your suggestion.

While the message is playing, is the whole sketch loop running? or does it go into some loop of its own?

I have 640 bytes of ram over so hopefully I can add my bcd converter to the top without trouble.

So now I must play with the triggering and add the other files.

Thanks

OK I have got the Holtek decoding working, and I can latch in the wireless push button numbers ( 1-9 ) in a variable called "track"

I hope I haven't taken too much memory, I am using 9 look up lines to convert the 4 digit bcd to a single number.

I also have the momentary valid transmission "valid" whenever a new ( or the same ) transmitter button is pressed.

I now need to play one of 9 messages from the SD card in my mockup of a Waveshield.

I have looked at a few examples, but I want it to queue, i.e. if a second request comes in while its playing the current message ( each about 3 seconds long ) it must finish the current message, then play the next track.

There is a nine message player at
 http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1230434365 but apart from the card checking, its not commented on, and I don't know what bits to omit or change.

Any suggestions?  

I know I should be starting with easier projects, but I have been bragging about the Arduino and its forum, and if I can get this working its going to be a real feather in Arduinos cap   8-)

No I dont know the amswer, I think I have read too many tutorials and got confused.
But for now it seems the best bet would be to use a 2 dollar HT12D and take the 4 data outputs ( the BCD number )  to 4 pins, and call up the array
   int  MyPins []={3,4,5,6}

as well as the Valid Transmission from the HT12 to and with the result.

Would I then use  a  byte()  function to change the array to a byte for the track number of the VaveShield ?

or if the array is a string perhaps atoi ?

Just trying to get the basic idea together