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Topic: 132 LED PWM IC help. AS1130 (Read 2018 times) previous topic - next topic

funkyguy4000

Hello,

So i've had this IC for ages and I have never been able to use it, although I would love to be able since its a 132-channel PWM driver from just a little 28-pin IC.

I've looked at the datasheet and it seems as if it could be controlled by using Arduinos Wire library although I'm not sure.

Could somebody please take a good look at this datasheet for the IC and dumb it down a bit for me?

The button for the datasheet is right below the AS1130 header.
https://shop.austriamicrosystems.com/eng/Products/Lighting-Management/LED-Driver-ICs/AS1130
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majenko

Yes, it's I²C controllable.  That's what the "Wire" library (why it's called that and not the i2c library I haven't yet fathomed) on the Arduino.

The chip basically uses Charlieplexing, the same method as the LOL shield.

funkyguy4000

So I would just control it with the Wire library.

I've never done anything with Wire as I don't fully understand l2C.
This'll be fun.

SDA and SCL on the Arduino are defaulted on some Analog pins, am I correct?
Accelerate to 88 miles per hour.

majenko

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SDA and SCL on the Arduino are defaulted on some Analog pins, am I correct?


I believe so.  I'm an SPI guy myself.

funkyguy4000

And then another question.  Does this chip allow for individually addressable leds?  Since there are only 28 pins on one of the packages, I'm curious as to if  I can bit bang with this.
Accelerate to 88 miles per hour.

Grumpy_Mike

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why it's called that and not the i2c library I haven't yet fathomed

It is short for two wire bus, true a bad name but there you are.

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SDA and SCL on the Arduino are defaulted on some Analog pins, am I correct?

Not only default but can only use A4 & A5

You need a 4K7 pull up on the pins as well.
That chip has an address of 0x30 if all three address inputs are wired to ground.

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Does this chip allow for individually addressable leds?

Yes

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I'm curious as to if  I can bit bang with this.

Not sure what you mean.

funkyguy4000

4k7, never heard of that amount. Do you mean 47k? 

I don't get the 0x30

So what kind of command would I send to this to make say the first channel light up if I were to use LEDs?
Accelerate to 88 miles per hour.

Grumpy_Mike

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Do you mean 47k? 

No I mean 4K7 or maybe you would understand 4.7K

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I don't get the 0x30

It is the address of the chip to use when talking to it with the wire library. It is a value in hex.

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So what kind of command would I send to this to make say the first channel light up if I were to use LEDs?

The sort of command you would need would be a write to the appropriate register. The exact command will take studying of the data sheet.

funkyguy4000

MMkay, yea i've never seen the notation 4K7.  But now I know.

I'll study up on the sheet. Thanks a bunch!
Accelerate to 88 miles per hour.

Grumpy_Mike

Check out this link there might be some software written for it already.
http://forum.sparkfun.com/viewtopic.php?f=5&t=31818

Looks a great chip, each LED can have it's brightness individually set. Do you know where you can get it from?

funkyguy4000

Oh, haha thats me!
I'd forgotten about that thread. 

You can get it from here:
http://www.eciaauthorized.com/search/AS1130-BWLT
Accelerate to 88 miles per hour.

GoolGaul

Any luck with these chips?

I am very interested, but certainly couldn't build a library for them...

funkyguy4000

I will be working with them as soon as my breakout boards come in the mail. 

Let me give you a rundown of these chips:

First off, they are I2C, as in you only need the power lines and then the SDA and SCL lines.  That means that you can use this without it's own library, you can instead use the Wire library.  Its own library would make it easier although through practicing with I2C, and reading the datasheet thoroughly, you can use them fairly easily.  You can find videos and tutorials about I2C on youtube.

Secondly, the way that this chip can PWM so many leds with so few pins is because it drives charlieplexed arrays.  They call it crossplexing, but its charlieplexing.  You can see the diagram of how the leds to be driven are set up.  One pin connects to a row of anodes and a column of cathodes, the next pin connects to the next row of anodes and the next column of cathodes, effectively making the array charlieplexed.  You can read up on charlieplexing on wikipedia as well as at Grumpy_Mikes website.

Thirdly: These aren't cheap chips.  You can get a sample from them for 3 of the chips although for purchasing them, they only take orders over 1000 pieces from their website.  I believe one of the major distributors (Digi-key, mouser, jameco, futurlec, tayda electronics, not sure if its one of those or one I forgot) sells them piece by piece.  Buying them one by one sets a price of about $6.00 each.  Buy in bulk, and you can drive that down to about $1.99 a piece at 1000 pieces.

Do me a favor and reply to this so that it is in my replies and I remember to let you know how my experimentation goes.
Accelerate to 88 miles per hour.

Grumpy_Mike


funkyguy4000

I should probably let you know when I expect to be able to test it just so I don't leave you hanging.

I ordered the boards to be fabricated on the 18th I believe.  I expect to get them at school around September 10th.  I'll try to get to using them as soon as I can afterwards although seeing as how I'm taking 16 credits and 4 free online classes as well as doing app consultation, I may not be able to get to it right away. 

I'll let you know when I get the boards
Accelerate to 88 miles per hour.

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