LED Display Drivers
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Hello: Anyone with experience driving 7 segment LED displays using
the Micrel MM5450 or similar chips. I'd be most interested in sample
code and experience whether or not it's worth the hassle using the
chips. Thanks
the Micrel MM5450 or similar chips. I'd be most interested in sample
code and experience whether or not it's worth the hassle using the
chips. Thanks
Comments
> Hello: Anyone with experience driving 7 segment LED displays using
> the Micrel MM5450 or similar chips. I'd be most interested in sample
> code and experience whether or not it's worth the hassle using the
> chips. Thanks
Sure, they're pretty easy to use. They are best when used with non-standard
displays, when non-numeric characters are desired, and when individual LEDs
are being driven. If you just want to drive a display with numbers, you
might prefer a BCD to 7-seg chip.
Anyway, here's the code I use for this chip:
Low CSpin ' Data Enable, CS line low
Shiftout DATpin, CLKpin, MSBFIRST, [noparse][[/noparse]1\1, Number\16, Number2\16, Number3\3] '
Output display data
High CSpin ' Data disable, CS line high
The 1\1 is the start bit and Number, Number2, and Number3 contain the data
to be displayed. Three variables are required because the Stamp can only
shiftout 16 bits at a time, and max variable size is 16 bits. One thing
you'll want to watch is how many bits you shiftout. You have to use exactly
36 bits, or you'll get erratic results even if you aren't driving all 35
outputs.
- Robert