led dot matrix display

PFloyd36069

hello,

i have a led dot matrix display similar to this one but not as fancy( http://www.avagotech.com/docs/AV02-0195EN), and i have got it working, and am able to type the numbers into the code( eg. three). i was wondering what i would need to do to be able to just send it a decimal from say another cog that is reading a sensor or something. ill post what i have so far·of the code....


Thanks,

Bryan

MagIO2

Well, instead of using hardcoded digits (zero, one, ...) , you can use:

value:= byte[noparse][[/noparse] @zero + (digit[noparse][[/noparse] 0 ]*5) ][noparse][[/noparse] i ] | byte[noparse][[/noparse] @zero + (digit[noparse][[/noparse] 1 ]*5) ][noparse][[/noparse] i ]<<7 | byte[noparse][[/noparse] @zero + (digit[noparse][[/noparse] 2 ]*5) ][noparse][[/noparse] i ]<<14 | byte[noparse][[/noparse] @zero + (digit[noparse][[/noparse] 2 ]*5) ][noparse][[/noparse] i ]<<21

This way your code only has to change the values in the digit-array for displaying other numbers. You understand the change? @zero is the base address of your character-definitions. If you want to display a "0" you can start at address @zero + 0 * 5. If you want to display a "7" you'd start at address @zero + 7 * 5, because each character needs 5 bytes in your definition.

But .. are you sure that you have to repeat the output loop when nothing has been changed?

PFloyd36069

Yeah that makes sense.· Im not sure though if it needs to repeat the output loop or not.·I cant really try it either because im at school right now.

thanks,

bryan

MagIO2

I had a closer look into the datasheet and it looks like the controller has to send the data for each refresh cycel, so your loop is OK.

PFloyd36069

I·got it working·just·like i wanted it to·now. Thanks for the help

Mike Huselton

Just came across this: www.edn.com/leds/article/ca6716496.html

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