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Controlling led matrix with mm5450

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Wbdsgnr

New Member
A friend and I have been discussing about wether we can controll up to 5 led matrixes of 5x7 linked together with the IC mm5450 using i²c. These are the datasheets:

https://www.electro-tech-online.com/custompdfs/2004/11/mm5450.pdf (controll ic)
https://www.electro-tech-online.com/custompdfs/2004/11/disp-11.pdf (led display)

We intend to use only one color of the display. I thought we should be able to controll every led led just by setting the corresponding row+column.. But this is our first project concerning such ic's.. We can't find any circuits with this mm5450 ic... So does anyone know if we are right?
 

Roff

Well-Known Member
What's up with figs 3b and 4b in the MM5450 datasheet? Seems like some pin names are missing.
Anyway, since you have (5+7)*5=60 LEDs, you should be able to divide that up into 2 groups of 30, connect those two groups in parallel and to 30 of the output pins of the 5450, and use 2 of the output bits to duplex between the 2 groups as is done in Fig. 13.
Edit:
I just noticed that the transistor in the upper right corner of Fig. 13 is shown as an NPN. It should be a PNP, like the other one.
 
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