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Tpic6b595 — Parallax Forums

Tpic6b595

LoopyonionLoopyonion Posts: 24
edited 2013-10-10 07:10 in Propeller 1
Hi,

I have picked up some of these for an experiment, after reading some of JM's posts.

Now, Ive looked high and low for a circuit diagram example, and an object to utilize them. I can find a fair bit of info on the 74x595, and JM_595_ez in obex.

Id basically like to output led sequences, to 16 leds at 5v, so using 2 x TPICB595's

Have I missed an obvious post on here? :)

Thanks again in advance for your help.

Comments

  • JonnyMacJonnyMac Posts: 9,107
    edited 2013-10-08 13:37
    They behave just like 74x595s -- the exception being that active outputs are open-drain instead of active-high TTL. This means you'll want to connect your positive source to the anodes of the LEDs, and connect their cathodes (with appropriate current limiter) to the outputs of the TPIC6A595. The nice thing about these devices is that they will sink up to 350mA per channel; that's a lot of current for LEDs.

    Note that the Vih spec of the part suggests that 3.3v from the Propeller won't work without a level shifter, but I've read posts by others that indicate a direct connection on the clock, data, and load lines is okay.
  • Duane DegnDuane Degn Posts: 10,588
    edited 2013-10-08 13:40
    The main difference between the TPIC6A595 and 74x595 chips is the TPIC6A595 can only sink current.

    I used some TPIC6B595 chips with my RGB LED arrays. I'm pretty sure the only difference between the A and B version is the amount of current they can sink. The schematic provided in my RGB LED array thread should work with TPIC6A595 chips.

    Most '595 code should work with your chips. You just need to keep in mind you're turning on the output as a sink and not a source of current.

    Edit: I just saw JonnyMac's post. I haven't used the "A" version but the "B" version I've used works fine with 3.3V logic.
  • LoopyonionLoopyonion Posts: 24
    edited 2013-10-09 01:45
    Jonny, Duane, Thanks again. It appears after a sleep and coffee, that I have the TPIC6B595's which should make things WAY easier. I have tried to edit the topic title, but no joy :) However, for testing and learning, I should have enough to be going on with!:)
  • Duane DegnDuane Degn Posts: 10,588
    edited 2013-10-09 09:02
    Loopyonion wrote: »
    I have tried to edit the topic title, but no joy

    If you edit your original post to this thread and choose "Go Advanced", you can then edit the Title box. This will change the title on the main forum page but the individual posts will have the old title (unless poster edit the title in their old posts).
  • LoopyonionLoopyonion Posts: 24
    edited 2013-10-10 00:11
    Working as of yesterday afternoon:) Using Duane's diagram, checking the pinouts with the TPIC sheet, 16 LED's, . Jonny's driver, and 2 cascaded TPIC's. Result.. And a little more straightforward than I expected. Great result, and a good step forward.:) Thanks very much for your assistance again
  • JonnyMacJonnyMac Posts: 9,107
    edited 2013-10-10 07:10
    With a PASM driver you can even have PWM control of your LEDs. I did it for a friend and am doing it on a client project now.
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