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Topic: 8*8 led matrix with 74hc595 (Read 1 time) previous topic - next topic

MostafaHamdy

i want to make LED screen using a lot of 8*8 led matrix  and i need to send data from arduino to show in it , i need simple code to show any letter on it , can i found library like lcd library,i need to use this matrix like lcd define the row and coulmn then send data will written and disappear if i clear it 

CrossRoads

One approach is to use a MAX7219 for each 8x8 matrix. $1.25 from taydaelectronics.com
They can be daisy chained so only a few arduino pins are needed to control them as one long chain.
http://www.taydaelectronics.com/catalogsearch/result/?q=max7219

Designing & building electrical circuits for over 25 years.  Screw Shield for Mega/Due/Uno,  Bobuino with ATMega1284P, & other '328P & '1284P creations & offerings at  my website.

MostafaHamdy

I finished  hardware connections with two 74hc595 for one 8*8 led matrix , i need simple code to set cursor then print data into led matrix or clear it or any library can help me

CrossRoads

Post your schematic, no one can offer code without seeing the hardware it is driving.
Designing & building electrical circuits for over 25 years.  Screw Shield for Mega/Due/Uno,  Bobuino with ATMega1284P, & other '328P & '1284P creations & offerings at  my website.

MostafaHamdy


CrossRoads

Any details on the matrix? Like which pins are anodes or cathodes?
As drawn, you should multiplex LED by LED.  Code was posted on doing just that over the weekend I believe.
The 74HC595 is only rated to sink/source 70mA total per the package; if you drive all 8 LEDs (in a columm or row) from 1 '595 with more than 8-9 mA, and sink all that current with 1 pin in the other '595, the 2nd '595 will see too much current.
Designing & building electrical circuits for over 25 years.  Screw Shield for Mega/Due/Uno,  Bobuino with ATMega1284P, & other '328P & '1284P creations & offerings at  my website.

MostafaHamdy


Any details on the matrix? Like which pins are anodes or cathodes?
As drawn, you should multiplex LED by LED.  Code was posted on doing just that over the weekend I believe.
The 74HC595 is only rated to sink/source 70mA total per the package; if you drive all 8 LEDs (in a columm or row) from 1 '595 with more than 8-9 mA, and sink all that current with 1 pin in the other '595, the 2nd '595 will see too much current.


Row anode

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