Go Down

Topic: AS1130 First attempt - working (Read 22964 times) previous topic - next topic

funkyguy4000

He's kinda right.  What exactly do you not quite get yet, so we can help you out?
Accelerate to 88 miles per hour.

Hexadec

#31
Oct 12, 2012, 10:09 am Last Edit: Oct 12, 2012, 10:16 am by Hexadec Reason: 1
Quote
"The only hurdle I see really is that I'm not sure if the Arduinos Wire library will work with it."

Do you (or anybody else) know if there is another library I could use instead?


Code: [Select]
//Use Wire Library to do I2C communication  
#include <Wire.h>        


Code: [Select]
/***** Function to write commands and data to I2C bus ***************************/
uint8_t I2C_write(uint8_t command, uint8_t data)
{
 Wire.beginTransmission(AS1130ADDRESS);
 Wire.write(command);
 Wire.write(data);
 int ack = Wire.endTransmission();
   #ifdef DEBUG
     if (ack != 0)
     {
       Serial.print("Error: ");
       Serial.print(ack);
       Serial.print("\r\n");
     }
   #endif
 return ack;
}


Code: [Select]
 
/***** Start-up sequence as per datasheet - see Page 13 ******************************/
// (1) define ram configuration - see table 20 page 25
// (2) Fill the On/Off Frames with our data
// (3) Set-up Blink & PWM sets
// (4) Set-up Dot Correction (if required)
// (5) Define Control Registers - see table 13 page 20
// (6) Define Current Source (0 to 30mA) - see table 19 page 24
// (7) Define Display Options
// (8) Start Display (Picture or Movie) Movie takes precedence over Picture


The above answers every question you asked to start with and is all taken from my example code.  ;)

Quote
And if I use four AS1130 to build a 11x48 Matrix, how do I have to connect the Sync Pins?
1. I'll do it like in the datasheet, on p.32 Figure 27., that there is only one Sync-Pin configured as Sync_Out and the other three AS1130 are Sync_In and then the Sync_Out is connected to the three Sync_In? But that means that the clock speed will decrease?!
Therefore I have a 2. solution: To configure every Sync Pin of the four devices as Sync_Out that each of them works (with their own oscillator) independent from the others ?


You need to understand what the sync does.
How do you conclude that the clock speed will decrease?  :~
GOLDEN RULE: If it says it in the datasheet...it is 99.9999999% the way it's GOT to be done.

Quote
In the Datasheet is written: "After a first write of data to the frames, the configuration is locked in the AS1130 config register and can be changed only after a reset of the device. A change of the RAM configuration requires to re-write the frame datasets."


That is refering to the RAM configuration. You have to choose at setup time which configuration you want (1-6) For example you can have 36 frames and 1 PWM set or 18 frames and 4 PWM sets etc.
See Table 8 in the datasheet.

A soft reset can be performed using the Shutdown register...Table 23 but I have a reset button because I am developing software and want to ensure that all the data etc is cleared on restart.




Sponge.
I'm allowed to have it 'cos it's not sharp.

Hexadec

Sponge.
I'm allowed to have it 'cos it's not sharp.

Hexadec

#33
Oct 13, 2012, 10:18 am Last Edit: Oct 13, 2012, 10:24 am by Hexadec Reason: 1
Quote
I asked you some questions in my last post hexadec


That's right...you did. Trouble is (for you) that it isn't one of my life's priorities to answer your questions immediately...

Quote
So of what was funkyguy4000 talking there?


Don't know (and don't really care) why don't you ask HIM.

Quote
But would the circuit also work if I use four Sync_In Pins and let them work with their own oscillator that they are independant of the other devices clock?


You STILL haven't looked at what sync is/does...
If you want the chips to work independantly then don't use sync...if you want them synchronised then use sync. Not rocket science is it?



Now go away, learn some politenness and manners - then come back.




Sponge.
I'm allowed to have it 'cos it's not sharp.

Hexadec

#34
Oct 13, 2012, 09:53 pm Last Edit: Oct 13, 2012, 09:59 pm by Hexadec Reason: 1
I know this isn't strictly Arduino, but here's a video of where I'm up to and what's possible with this chip.

I'm now uploading the page data to the AS1130 through the MCU (could easily be an AVR  :smiley-mr-green:) from the PC.
The PC app takes data produced in a spreadsheet, converts it to binary format and uploads it to the external eeprom on the PIC board.
It then gets uploaded to the AS1130 as 36 frame pages. At the moment I'm using 10 x 36 frame pages (which will fit easily onto an AtMega328).

http://www.youtube.com/watch?v=JH9rZseoP2E

If anyone wants the source code for the PIC or the PC app. just ask.


I WILL be porting the code for the Arduino...but time is at a premium unfortunately  :(
Sponge.
I'm allowed to have it 'cos it's not sharp.

Hexadec

Quote
I'm really sorry Hexadec


No problems mate...I was feeling a bit grumpy that day.  :smiley-mr-green:

It's best to think of the AS1130 as a completely separate entity which can receive data and instructions at 1Mhz over the I2C bus.

Once you have set up the AS1130 by sending instructions and the frame data and telling it to start, it will display the frames one by one at whatever rate you told it to.
It will do this forever without any more communication with whatever is sending instructions to it.

The fastest time between frames is 32.5mS  which is about 31 frames per second - the slowest is 487.5mS which is about 2 per second. (see Table 17 frame_delay)

While the AS1130 is displaying the frames you can upload another set of frames and it will display them. (It displays whatever is in it's eeprom 1 frame at a time)

Now think of the microcontroller as a seperate entity.

It can send instructions over I2C and stream data as fast as the receiver connected to it can process it.
It has eeprom memory that can hold binary arrays (in this case our frame data) until it is full.
It can communicate and exchange data with an external eeprom and send that data out over I2C. 

Now put them together...

MCU sends instructions and frame data to AS1130 and tells it to start.
AS1130 displays the frames on it's own and ignores the MCU.
MCU gets another 36 frames of data either from its own eeprom, an external eeprom, the serial bus or anywhere else that can be connected to it.
All this time the AS1130 is happily displaying the frames...
MCU sends new frame data to AS1130.

The cycle continues until the power goes down.  :smiley-mr-green:

Don't forget you can also send instructions to the AS1130 while its running as can be seen in the video.


The speed that the frames are displayed is constrained to one of 15 different speeds set in the Frame Time/Scroll register and has nothing to do with the clock speed the I2C bus speed or the MCU speed.

Hope that is now clear.... 8)

Sponge.
I'm allowed to have it 'cos it's not sharp.

funkyguy4000


@funkyguy4000 :

Of what were you talking there about that library?


I was speaking of the Wire library that Arduino uses.  I'm not sure if the ATmega128 that you are hoping to use will work with it,  my advice would just to try it out and see what happens.  I see no reason why it wouldn't work but also I wouldn't stand by that statement.  Just do some experimentation to see if it works.  If it does, could you kindly let us know?
Accelerate to 88 miles per hour.

funkyguy4000

You'll have to go to the libraries folder of the arduino ide program and open it up in some sort of C programming environment
Accelerate to 88 miles per hour.

Graynomad

<your arduino insall folder>libraries\Wire


_____
Rob
Rob Gray aka the GRAYnomad www.robgray.com

Hexadec

Well spotted.... :smiley-mr-green:

When I was first looking at this chip I read somewhere that the sync line was open drain which I don't like to leave floating. (it isn't)

So, yes it's a mistake.  =(

As stated earlier in the thread, it doesn't matter if the sync is up, down or indifferent unless you are using it.  :)
Sponge.
I'm allowed to have it 'cos it's not sharp.

Hexadec

I don't think it will make any difference...I just have loads of electrolytics  :smiley-mr-green:
Sponge.
I'm allowed to have it 'cos it's not sharp.

Hexadec

I haven't done anything yet with 2 screens, so I don't know.

I would guess that you should sync the two displays then use an interrupt to control the scroll time.

If I were you...I wouldn't complicate the issue by doing this yet...I would get a firm understanding of using ONE chip and ONE screen before you go further.  :D
Sponge.
I'm allowed to have it 'cos it's not sharp.

Hexadec

#42
Oct 16, 2012, 11:44 am Last Edit: Oct 16, 2012, 11:53 am by Hexadec Reason: 1
not stupid at all....

I just used cheap ordinary 2V, 20mA red.
Sponge.
I'm allowed to have it 'cos it's not sharp.

Hexadec

Nooooooo......all the VDD pins are connected internally...you just need ONE 10uF cap for each seperate AS1130.

The 4K7 on all pins should be fine.

Sponge.
I'm allowed to have it 'cos it's not sharp.

Hexadec

#44
Oct 16, 2012, 09:53 pm Last Edit: Oct 16, 2012, 09:54 pm by Hexadec Reason: 1
On the first board I made I connected all the VDDs and VSSs together...what a waste of time... :smiley-red:  :D

On the board I'm using for all the demos...pin 3 is connected to VDD and pin 1 to VSS, the cap is connected to both of them.

If you do a continuity test with a meter, you'll find the VDD pins are all connected together, as are the VSS.
Sponge.
I'm allowed to have it 'cos it's not sharp.

Go Up