MAX 7219 LED Controler
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Posts: 46,084
Has anyone used one of these? I saw the Nuts and Volts column on it
and decided to give it a try but as soon as I power it on all of the
segments come on. I can't turn them off.
Has anyone seen this before and/or know what's causing it? I've
double checked my circuit about 10 times now so I'm sure it's wired
correctly.
and decided to give it a try but as soon as I power it on all of the
segments come on. I can't turn them off.
Has anyone seen this before and/or know what's causing it? I've
double checked my circuit about 10 times now so I'm sure it's wired
correctly.
Comments
have erred in my N&V column. There are other resources at Parallax that have
code and schematics for the MAX7219. You may want to check them out.
<A
HREF="http://www.parallax.com/detail.asp?product_id=603-00001">http://www.parall\
ax.com/detail.asp?product_id=603-00001</A>
<A
HREF="http://www.parallax.com/detail.asp?product_id=27220">http://www.parallax.c\
om/detail.asp?product_id=27220</A>
-- Jon Williams
-- Parallax
In a message dated 1/15/2003 1:19:23 PM Central Standard Time,
selket_10027@y... writes:
> Has anyone used one of these? I saw the Nuts and Volts column on it
> and decided to give it a try but as soon as I power it on all of the
> segments come on. I can't turn them off.
>
> Has anyone seen this before and/or know what's causing it? I've
> double checked my circuit about 10 times now so I'm sure it's wired
> correctly.
[noparse][[/noparse]Non-text portions of this message have been removed]
7219 is getting a 'surge' or misplaced bit during communication. Make sure
you have the pulldown resistors as shown on Jon's programs. Watch what you
put in those 7219 and how your wire them up 'cus they are easy to fry. I
have to run, I'm headed out of state for a week but I would love to hear
from others and if you solve your problem. I am working on an interface
with the 7219 to boost its output and isolate it from the leds. Dan
Famous last words... <grin> ...we've all miswired projects and I may even
have erred in my N&V column. There are other resources at Parallax that
have
code and schematics for the MAX7219. You may want to check them out.
<A HREF="http://www.parallax.com/detail.asp?product_id=603-00001
">http://www.parallax.com/detail.asp?product_id=603-00001</A>
<A HREF="http://www.parallax.com/detail.asp?product_id=27220
">http://www.parallax.com/detail.asp?product_id=27220</A>
-- Jon Williams
-- Parallax
In a message dated 1/15/2003 1:19:23 PM Central Standard Time,
selket_10027@y... writes:
> Has anyone used one of these? I saw the Nuts and Volts column on it
> and decided to give it a try but as soon as I power it on all of the
> segments come on. I can't turn them off.
>
> Has anyone seen this before and/or know what's causing it? I've
> double checked my circuit about 10 times now so I'm sure it's wired
> correctly.
[noparse][[/noparse]Non-text portions of this message have been removed]
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