8x8 bicolor matrix and max7219 (please help)
bytor95
Posts: 53
Hi,
I'm trying to interface with a bicolor 8x8 matrix (see attachment).
So far I've used a single max7219 chip with a basic stamp sx processor. I figured that part out and now can access all 64 leds and make them all individually light up GREEN using 8 lines (Dig 0 thru Dig 7) and 8 lines (A thru DP) for the Common cathode lines.
Up until now, everything works and I'm amazed I got this far. Now I'm trying to access the red lights. I need 8 more lines so I tried using another max7219. After struggling with cascading for way too long, I finally have both chips working but my problem is that I'm having trouble with the wiring and the multiplexing.
Has anyone multiplexed 2 sets of 64 leds with a common cathode using two max7219 (or another chip)? In other words, what I'm working with is the same as using 64 three-leg bicolor LED's.
This is what I bought (they really are amazing to work with especially for the price)
http://cgi.ebay.com/Lot-of-10pcs-8x8-dot-matrix-3mm-dia-LED-display-bicolor_W0QQitemZ230101239258QQihZ013QQcategoryZ26207QQssPageNameZWDVWQQrdZ1QQcmdZViewItem
Thanks!
Engin
Post Edited (bytor95) : 3/7/2007 5:04:11 PM GMT
I'm trying to interface with a bicolor 8x8 matrix (see attachment).
So far I've used a single max7219 chip with a basic stamp sx processor. I figured that part out and now can access all 64 leds and make them all individually light up GREEN using 8 lines (Dig 0 thru Dig 7) and 8 lines (A thru DP) for the Common cathode lines.
Up until now, everything works and I'm amazed I got this far. Now I'm trying to access the red lights. I need 8 more lines so I tried using another max7219. After struggling with cascading for way too long, I finally have both chips working but my problem is that I'm having trouble with the wiring and the multiplexing.
Has anyone multiplexed 2 sets of 64 leds with a common cathode using two max7219 (or another chip)? In other words, what I'm working with is the same as using 64 three-leg bicolor LED's.
This is what I bought (they really are amazing to work with especially for the price)
http://cgi.ebay.com/Lot-of-10pcs-8x8-dot-matrix-3mm-dia-LED-display-bicolor_W0QQitemZ230101239258QQihZ013QQcategoryZ26207QQssPageNameZWDVWQQrdZ1QQcmdZViewItem
Thanks!
Engin
Post Edited (bytor95) : 3/7/2007 5:04:11 PM GMT
1087 x 670 - 118K
Comments
Engin
Post Edited (bytor95) : 3/7/2007 9:39:38 PM GMT
Engin
It may simply be that nobody has ever done bi-color work with this chip. I have used it many times myself but never with bi-color LEDs. Some members don’t logon everyday but maybe someone will come on who has something to contribute. Take care.
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Chris Savage
Parallax Tech Support
I just ordered the Max6954 chip that's supposed to control 128 LEDS. I think that was the answer (I hope).
Thanks Chris for replying.
Engin