Brusque,

Check input side of 74HC595 look for a glitch if there is any glitch 
then check your code if input side is fine then take a can of
freezer and cool it down it might be that 74HC595 chip is over loaded
let me know your result then we will continue from there.
Setup break points in your software if it looked fine then definitely
there is a glitch problem.  

Andre Abelian




-----Original Message-----
 
Hello,

     I'm glad to report that I'm using 6 cascaded 74HC595 to light 48 
LEDs, with 8 bit software PWM individual brightness control. I'm 
connecting the LEDs on the '595 outputs with 100R resistor and I'm 
getting, aprox, 9.5mA on the Green and Blue LEDs, 20mA on the Red LEDs. 
No '595 blown untill now. :)

     Now, other problem <grin>. Let's say I turn on LEDs 1, 4, 7 and so 
on. They turn on correctly, but I got ocasional blinks on the other LEDs

(2, 3, 5, 6 and so on).

     It's very weird. I'm scratching my head, looking at my scope, 
modifying my source code... no conclusions. The LEDs on the first and 
second '595 are ok, on the third it's happening, on the fourth it's 
worse, on the fifth it's even worse, on the sixt it's like sh*t.

     Someone can give any clues? Please, if you need more informations 
just ask.

     Thanks,

     Brusque
-- 
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Edson Brusque                     C.I.Tronics Lighting Designers Ltda
Research and Development                  Joinville  -  SC  -  Brazil
http://www.ryan.com.br/netiqueta.htm             www.citronics.com.br
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