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video LED Matrix Test 1 using an AS1107 IC
Got hold of some AS1107 LED Driver Chips from Austria Microsystems. These are designed for driving 8 x 8 segment LED numerical displays. They can also be used for controlling an 8x8 LED Matrix. Only 3 outputs are needed from the Boarduino (Arduino) - Clock, Data and Latch. There is absolutely zero examples on the internet of this IC being used and no code examples or libraries at all so I had to read the datasheet, work it out for myself and write all the code myself. This is the first time I have ever worked out how to control an IC from its datasheet so I am very proud of myself for doing what you see above in only a few hours.
Only one chip is needed to control the Matrix and NO MULTIPLEXING is required as the chip does all that for you!!! After you work out how the chip works it is pretty easy to code for. The video shows 3 functions I wrote for the matrix. One is the point function that turns an LED on at location x,y. Also Spiral which is an animation routine to draw a spiral with x millisecond delay inbetween frames. Also, the clearDisplay function and the scrollLeft function that scrolls the text left.
I have also tidied up the font and the font spacing since the previous tests.
www.earthshinedesign.co.uk
Only one chip is needed to control the Matrix and NO MULTIPLEXING is required as the chip does all that for you!!! After you work out how the chip works it is pretty easy to code for. The video shows 3 functions I wrote for the matrix. One is the point function that turns an LED on at location x,y. Also Spiral which is an animation routine to draw a spiral with x millisecond delay inbetween frames. Also, the clearDisplay function and the scrollLeft function that scrolls the text left.
I have also tidied up the font and the font spacing since the previous tests.
www.earthshinedesign.co.uk
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Jul 13, 2011. 7:48 PMcivicbynature
says:
Just bought a bunch of these chips from austriamicrosystems 4 bucks a piece. STOKED! Good job btw, Would love to see your wiring and code as well. Would just like to polity mention that there is still Multiplexing in your circuit. Since there's only 16pins on your LED Matrix and not 32 that means it's multiplexed.
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34
Apr 21, 2009. 8:27 AM
jeff-o
says:
jeff-o
says:
That is pretty spiffy! I like that chip, too... it should make some designs a lot simpler, especially if you want more than one 8x8 matrix.
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May 22, 2009. 9:02 PMGilo
says:
Great work. Please take a bow. Is the display expandable to take on more characters? ANyway it can be used with an input device like a keyboard? gilo
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10
May 25, 2009. 6:34 AMearthshine (author)
says:
Yes you can expand it for more modules. Keyboard input would be possible.
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1
Feb 21, 2010. 10:56 AMndinitz
says:
where can i get some of those led matrices?
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10
Apr 21, 2009. 8:28 AMearthshine (author)
says:
It's a great chip. It's more expensive than the MAX chips, but it sure makes life a lot easier to code. Plus having multiplexing on the chip frees up a LOT of clock cycles on your Microcontroller.
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Oct 12, 2009. 6:06 AMfaki
says:
Could you please post the circuit, and the code
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May 23, 2009. 4:59 PMfilmo
says:
Newark seems to have the chip for about $4 bucks. When I search for the Max 7221 it seems like it's about $10 bucks. Am I looking at the right chip?? I only ask because you mention that the MAX is more expensive, but it seems the opposite??
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May 23, 2009. 5:05 PMfilmo
says:
Actually from reading the data-sheets between the AS1107 and the MAX7221, it seems like the AS1107 is a direct knock off of the MAX chip. Was this your experience as well or is there something I missed between the two chips?
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10
Aug 12, 2009. 1:05 AMearthshine (author)
says:
Yes they are identical. Except the AS1107 is half the price of the MAX.
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