serial to parallel shifter.

Archiver

I am attempting to cascade two 74HC595 chips together so that i can
control an LCD and stepper motor with just three stamp pins. I have
the LCD working with the 595 chips and i am using the lower bits of
the 595 output to do so. When i cascade the 595 chips together i
just want to be sure that i can connect the clk and latch pins of the
chips together so that the stamp would control both chips. As
controling the stepper i am looking to use the upper 4 bits of the
second 595 chip. My main question is if i will be able to control
the stepper without affecting the LCD display? From my thinking i
figure that i would be able to simply alter the upper 4 bits of the
variable i use to send the data through the 595 chips and thereby no
affect the lower 6 bits used for the LCD.

Any response will be very helpful

Thanks
Anthony

Archiver

So long as you don't do anything with the output that connects to the LCD's E
pin when you're updating the stepper, you should be fine.

-- Jon Williams
-- Applications Engineer, Parallax


In a message dated 11/29/02 7:34:42 PM Central Standard Time,
engrmaps@y... writes:


> I am attempting to cascade two 74HC595 chips together so that i can
> control an LCD and stepper motor with just three stamp pins. I have
> the LCD working with the 595 chips and i am using the lower bits of
> the 595 output to do so. When i cascade the 595 chips together i
> just want to be sure that i can connect the clk and latch pins of the
> chips together so that the stamp would control both chips. As
> controling the stepper i am looking to use the upper 4 bits of the
> second 595 chip. My main question is if i will be able to control
> the stepper without affecting the LCD display? From my thinking i
> figure that i would be able to simply alter the upper 4 bits of the
> variable i use to send the data through the 595 chips and thereby no
> affect the lower 6 bits used for the LCD.
>
> Any response will be very helpful
>
> Thanks
> Anthony
>




[noparse][[/noparse]Non-text portions of this message have been removed]

Archiver

Yes you can. You just have to conect the latches of the two 595s. The
outputs appear only after triggering the latch(es). Thus, during the
shift-in
phase the outputs remain as they were.
regards
Adrian