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Using 74HC597 — Parallax Forums

Using 74HC597

JonathanJonathan Posts: 1,023
edited 2008-08-10 15:15 in BASIC Stamp
Hi All,

I need to use a 74HC597. I see the SW example of using the 74HC165, but the pinout of the '597 is different. Can anyone point me in the right direction for a connection diagram?

Also, what is the cosmic diff between the the two?

Thanks!

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Comments

  • Mike GreenMike Green Posts: 23,101
    edited 2008-08-09 14:47
    Download the datasheet from NXP (www.nxp.com/acrobat_download/datasheets/74HC_HCT597_CNV_2.pdf).

    It looks like the biggest difference is that the parallel load is a level for the 74HC165 and is edge triggered for the 74HC597.
    The pinouts are also different and there are some minor differences in the other signals.
  • JonathanJonathan Posts: 1,023
    edited 2008-08-09 14:55
    Mike,

    I had already DL'd the data sheet. I'm just not sure which pins to use, and if the code should be the same etc. Are there any Stamp/Prop examples of using this chip?

    Thanks!

    Jonathan

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    www.madlabs.info - Home of the Hydrogen Fuel Cell Robot
  • PJAllenPJAllen Banned Posts: 5,065
    edited 2008-08-09 15:51
    To shift data into the Stamp?
  • JonathanJonathan Posts: 1,023
    edited 2008-08-09 16:07
    Yes, to shift data in to the Stamp or Prop. The hookup diagrams I have found reference the load pin, but all the code examples I have found are in assembly for PICs etc.

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    www.madlabs.info - Home of the Hydrogen Fuel Cell Robot
  • PJAllenPJAllen Banned Posts: 5,065
    edited 2008-08-09 16:09
    I think this would be the easiest implementation:

    74HC597_imp.jpg
  • JonathanJonathan Posts: 1,023
    edited 2008-08-09 16:33
    PJ,

    Lets see if I have this right, I would toggle SH(11) from low to high, then shift data in from Q(9) using L(12) as the clock? No need for a fourth I/O line? Other schematics I have seen use 4.

    Thanks a ton for the help!

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    www.madlabs.info - Home of the Hydrogen Fuel Cell Robot
  • PJAllenPJAllen Banned Posts: 5,065
    edited 2008-08-09 16:57
    No, no, no.

    Do a PULSOUT (normally lo, goes hi then lo) to pin12, that locks what's on the data lines.· Then shift data in from Q using pin11 as the clock line.

    As I noted, my sketch was for the easiest implementation.· If you want to clear the clock with MR then you'll need a pin for that and for PL.·
  • PJAllenPJAllen Banned Posts: 5,065
    edited 2008-08-10 02:33
    Reviewing datasheet --

    1) PL has to be low when you latch the data.

    2) PL (and MR) has to be made HI when you clock out data.


    Post Edit -- dwg added

    Post Edited (PJ Allen) : 8/10/2008 2:48:22 AM GMT
    74HC597_imp.jpg
    400 x 312 - 17K
  • JonathanJonathan Posts: 1,023
    edited 2008-08-10 14:31
    PJ,

    Got it working! Although I had to use 4 I/O to do it. I needed to strobe the latch hi/lo, then strobe the load line lo/hi.

    Thanks for all the help. Now I have to figger out how to cascade 'em and I can get on with my project.

    Jonathan

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    www.madlabs.info - Home of the Hydrogen Fuel Cell Robot
  • JonathanJonathan Posts: 1,023
    edited 2008-08-10 15:15
    Got it working cascade style. One last question, can I get away with using 470kOhms for the input pulldowns? I have a lot on hand and I am a little low on 10ks. The inputs will be reading switches.

    Thanks again for all the help!

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    www.madlabs.info - Home of the Hydrogen Fuel Cell Robot
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