Controlling 5x7 led arrays

halfblinddado

I want to control 2 5x7 led arrays. I have found a way to do it using 2 HC138 3 to 8 line decoders. I can program letters numbers animation and so on with 16 bit numbers. (See schematic and code attached).

a_right:
LEDs = 0
LEDs = %0000000000001110
LEDs = 0
LEDs = %0010010000010001
LEDs = 0
LEDs = %0100100000010001
LEDs = 0
LEDs = %0110110000011111
LEDs = 0
LEDs = %1001000000010001
LEDs = 0
LEDs = %1011010000010001
LEDs = 0
LEDs = %1101100000010001
RETURN

The first 6 bits control the decoders(which control·the rows)·and the second 10 bits control the columns.



As you can guess this takes up alot of program space and the The ASCII characters A-Z won't fit on the basic stamp.

My question is: Is there a good way to compress the data?

Thanks

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"Everything is working so why do we pay him?"


"Nothing is working so why do we pay him?"

Mike Green

You can easily store the font information using DATA statements and access it using READ statements. You need 7 x 2 = 14 bytes for each character. You can easily store a 64 character font in about 900 bytes (roughly 1/2 the EEPROM). Look at the chapters on the DATA and READ statements in the Basic Manual or the Stamp Editor's help file.

halfblinddado

Does DATA store binary words? Is the only way to do this is to convert binary into decimal?

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"Everything is working so why do we pay him?"


"Nothing is working so why do we pay him?"

dev/null

DATA stores words if you prefix each item with Word.
DATA Word "AB",Word "BC", etc...

Beware that each item has 2 bytes (2 address positions) when you READ them.

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Don't worry. Be happy

T&E Engineer

Take a look at another ways to do this with a BS2:



http://forums.parallax.com/showthread.php?p=561144

You can also use the MAX7219. Do a search for MAX7219 in this forum area.

You will definately need external hardware chips to control this. This is probably a better project for a SX chip or Propellor.