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61  Using Arduino / LEDs and Multiplexing / Re: AS1130 Ongoing Discussion 132 Individually controllable, PWM LED driver on: December 28, 2012, 03:57:52 pm
Oops...forgot to mention...

The CS register is limiting at 15mA and the whole 528 LEDs, four AS1130 chips, 1 512Kb EEPROM and an 18F2550 running at 48 MHz are all powered by the USB....  smiley-cool


Here's the usual crappy video...with and without 1 sheet of inkjet paper masking the LEDs.


http://youtu.be/Agxh7WkdDQs


You can at least see how fast the changeover takes place.  smiley-mr-green
62  Using Arduino / LEDs and Multiplexing / Re: AS1130 Ongoing Discussion 132 Individually controllable, PWM LED driver on: December 28, 2012, 03:32:49 pm
Just a quick update...I've now got the I2C bus running at 1Mhz and it's very stable. I spent a couple of hours today with the 'scope on the SCL pin and by experiment with the resistor values I've now got a very fast rise time on the clock pulses and it's almost a clean square wave. The bus capacitance on these chips is quite high individually and this was causing the problem. I originally used 4K7 resistors and they worked fine @100Khz and not bad at 400Khz...then while playing with changing almost a 1KB of data after a frame interrupt I found that there was a definite visible lag on changeover... smiley-mad I then upped the bus speed in increments of 100KHz until the reliability dropped dramatically.

Anyway...the time between the interrupt firing at the end frame and the start of the new frame PWM set is now very slightly over 217mS which I'm more than happy with. I've ordered some free sample 128KB, 1 MHz I2C EEPROMs from my lovely Microchip (  smiley-mr-green ) today so we'll see how fast it runs when pulling data from the external EEPROM...the sky should then be the limit for long animations with full 8 bit PWM... smiley-wink

@Binary
Quote
If you do a software reset and set the shdn-bit to 0, are all controll registers resetted then (set to default
values) ? because thats not written in the datasheet.

We have a saying in English Pantomime....

"OH Yes it is...."  smiley-razz

To save you looking (as it's your Christmas present).

If you reset 'shdn' the internal state machine stops and all outputs are turned off.
If you set 'shdn' the internal state machine starts and all outputs are turned on.

So you DON'T lose the register values.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
If you reset the 'init bit' then the state machine resets and you DO lose the register values.

Just like it says in the datasheet.
Happy New year mate.  smiley-mr-green

63  Using Arduino / LEDs and Multiplexing / Re: AS1130 Ongoing Discussion 132 Individually controllable, PWM LED driver on: December 25, 2012, 02:15:11 pm
Merry Christmas all.  smiley-mr-green
64  Using Arduino / LEDs and Multiplexing / Re: AS1130 Ongoing Discussion 132 Individually controllable, PWM LED driver on: December 16, 2012, 07:02:13 am
It'd be good if you could let me have the details...only problem is that I would have to have a board made for them and hand soldering 528 5050 LEDs does not fill me with joy... smiley-mr-green smiley-mr-green

Do you have a good manufacturer who would produce the board with the LEDs already soldered? Maybe we could look at that option...
65  Using Arduino / LEDs and Multiplexing / Re: AS1130 Ongoing Discussion 132 Individually controllable, PWM LED driver on: December 16, 2012, 04:33:47 am
No pressure...after all this is a hobby.  smiley-mr-green

I've got a few things to do myself but will continue with this project. I'd like to find some RGB LEDs that I can solder in a tight, even matrix then run with AS1130s...this chip would be perfect for colour mixing and I have ideas for full motion video if I can bulid a suitable screen.
66  Using Arduino / LEDs and Multiplexing / Re: AS1130 Ongoing Discussion 132 Individually controllable, PWM LED driver on: December 15, 2012, 07:13:33 pm
Yeah...pretty much the same code as before but for 4 chips and with the first chip as master sync, the other 3 as slaves...I didn't blank the changeover to the next six frames to show how fast it is.

So...frame data is just 6 frames all LEDs on...and 6 sets of PWM data for each animation.  smiley-cool

I've written a program which takes 6 frames of an animated gif and converts them to the data required for the 24x22 screen...I separate the frames in photoshop first then feed them to the C++ prog, then copy and paste to the MCU datafile.

I'm interested in what you want to do with this project as well...perhaps we can come up with something together....
67  Using Arduino / LEDs and Multiplexing / Re: AS1130 Ongoing Discussion 132 Individually controllable, PWM LED driver on: December 15, 2012, 03:09:21 pm
Well here it is at last.... smiley-mr-green

I've found it really difficult to film this with my iphone, but you get the idea I hope.

The LEDs are covered with a sheet of inkjet paper to try to difuse the light a bit.
The vids are full 8 bit PWM and are converted from animated gifs.

http://youtu.be/zMzKhonWhq0

Second one is further away...hope it makes some sense.  smiley-lol

http://youtu.be/sViovjihxvg

They look better in real life...honest guv.... smiley-razz
68  Using Arduino / LEDs and Multiplexing / Re: AS1130 Ongoing Discussion 132 Individually controllable, PWM LED driver on: December 06, 2012, 05:30:19 am
Thanks for doing this funkyguy old chap.

It's nice to clear out the cobwebs and have a fresh start.  smiley-mr-green

I am working on a library for the AS1130 which I will post at sometime but I've become a little distracted with writing code to convert video files to matrix LED data to use on my 24 x 22 screen.

I have soldered all the LEDs and connected them...I just need to connect up the other 2 AS1130s and hopefully we'll have a working 4 chip system to analyse.

I have ported my PIC code to the Arduino but have had to change the way the data is written to the chip. It's now faster but there are still issues with the Wire library that I don't encounter by bit banging on the PIC and which I still don't understand (but I'm getting there).

I've spent quite a long time looking at the data stream with a logic analyser...so I know what the problems are...I just need to find what's causing them.  smiley-eek

Obviously these issues need addressing before I can release a library.

Also I'm writing the class code to be fully OOP compliant and not just a usable bit of code.

Anyway I'm hoping to post a movie running on the 24 x 22 screen by next week showing a hand waving in full 256 level greyscale.
69  Using Arduino / LEDs and Multiplexing / Re: AS1130 First attempt - working on: December 06, 2012, 05:14:00 am
There is no hidden secret or trick to writing successful code from scratch. It is all hard work and research. You don't learn how to build a house by walking up to a construction crew, saying "Hey, I'm building a house too!" and asking them how to hold a hammer while they're working, and you don't own a hammer.


I wish I could have put it like that instead of waffling.... smiley-mr-green

Thanks for your understanding friend.
70  Using Arduino / LEDs and Multiplexing / Re: AS1130 First attempt - working on: December 05, 2012, 08:05:18 am
You're very welcome.

Now go and find a hobby that you are capable of....
71  Using Arduino / LEDs and Multiplexing / Re: AS1130 First attempt - working on: December 05, 2012, 04:39:04 am
You agreed that if I sent you the code you would not ask questions about it.

So...why did you send the PMs and emails asking questions?

If I share any more code here...it will be when I want to so don't bother asking again.

If you don't understand the code then go and learn somewhere else.

I give up.



@ Mods/Admin

Feel free to delete this thread as most of it is useless. I will post again when I have something to contribute.
72  Using Arduino / LEDs and Multiplexing / Re: AS1130 First attempt - working on: December 04, 2012, 02:46:49 pm
@binarygod

I don't know what you don't understand about "you are entirely on your own with it and will get very little help from me" but you bombarding me with PMs and emails asking questions about the code is the very reason I did not want to share it in the first place!

I WILL NOT answer PMs about the code in any shape or form.

I WILL NOT answer emails about the code in any shape or form.

I MAY answer Forum posts about the code if I have the time which is VERY unlikely

If that is not now clear I will give up entirely and you will never get any code from me in the future.
73  Using Arduino / LEDs and Multiplexing / Re: AS1130 First attempt - working on: December 04, 2012, 01:25:49 pm
Email sent...

In answer to your question in your PM I refer you to the following....

Quote
You are quite welcome to the Arduino code which will scroll a message across a 24 x 11 matrix using movie mode...

...BUT...

a) it is not well commented.
b) it is split into 4 files
c) I have no time to explain how it works
d) I am in the process of changing it on a daily basis.

If you want it on the basis that you are entirely on your own with it and will get very little help from me then I will email it to you.

Sorry.  smiley-small
74  Using Arduino / LEDs and Multiplexing / Re: AS1130 First attempt - working on: December 04, 2012, 01:17:16 pm
It's changed quite a bit but the principles are still the same.

PM me your email address and I'll zip it and send it.
75  Using Arduino / LEDs and Multiplexing / Re: AS1130 First attempt - working on: December 04, 2012, 11:30:43 am
You are quite welcome to the Arduino code which will scroll a message across a 24 x 11 matrix using movie mode...

...BUT...

a) it is not well commented.
b) it is split into 4 files
c) I have no time to explain how it works
d) I am in the process of changing it on a daily basis.

If you want it on the basis that you are entirely on your own with it and will get very little help from me then I will email it to you.  smiley-wink

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