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I only need Propeller? — Parallax Forums

I only need Propeller?

rearwheeldriverearwheeldrive Posts: 2
edited 2010-10-21 18:59 in Propeller 1
Hi everyone,

This is my first post here. A short introduction since I'm new to this board, propeller and in fact PLCs. I'm a web programmer by training with most electronics knowledge being self-taught (i.e. very novice). I got a BS2 some 5 years ago but did not get far with that due to work. Anyway I was looking up some information on BS2 to pick it up again and found out about Propeller, so here I am. :)

I've been reading up on this forum and also googling a lot (I just found out about RS485 5mins ago, don't laugh), so that's where I stand in terms of knowledge.

I intend to experiment and learn more about Propeller and PLC in general, though I do have a project in mind which I'll definitely post here as I'll expect to hit lots of road blocks.

Well, the title of this post is actually my first question.

I was reading up on displaying information which I started with 7-segment LEDs and learnt about recommendations to use a MAX7219, then I went on to read about the 20x4 LCD displays like the HD44780 compatibles.

I'm just wondering, can the Propeller be used in place of a MAX7219 or be used as a serial interface to the HD44780?

That is, can I have one Propeller doing all the processing and output the information to another propeller that is dedicated to converting the information to parallel to the LCD display?

Is there any reason not to do something like that?

I'm asking this as the price of the MAX7219 or the HD44780 serial backpack cost much more than the propeller chip itself.

Thanks in advanced!

Comments

  • W9GFOW9GFO Posts: 4,010
    edited 2010-10-21 12:19
    The Propeller can drive LCD displays directly. IF you use 4 bit mode it will require 7 pins, 8 bit mode requires 11 pins. There is no need to use a separate Propeller.

    Rich H
  • LeonLeon Posts: 7,620
    edited 2010-10-21 12:20
    If you multiplex the LEDs and use a transistor for each digit you can drive them directly from the Propeller without wasting pins. I've got a simple PCB design for four digits you can have.

    You can drive an LCD directly from the Propeller, as well. If you use 4-bit mode you don't need many pins.
  • kwinnkwinn Posts: 8,697
    edited 2010-10-21 12:22
    Welcome to the forum.

    The propeller can do all that and more. There are 8 CPU's in the propeller so it is not even necessary in most cases to have a separate prop dedicated to the display function. A single cog could do that. You could also have a prop generate a video display on an LCD or CRT display, and have a touch panel for input if desired.

    There are objects in the OBEX for all these functions and much more.
  • Invent-O-DocInvent-O-Doc Posts: 768
    edited 2010-10-21 12:59
    You will find that the propeller does these things easily. You will also find that the software comes with scores of pre-made objects to do these tasks. There are hundreds more online. The default software install includes more than 20 demonstrations that work with the hardware in the propeller demo board. That is a very easy way to start.
  • K2K2 Posts: 693
    edited 2010-10-21 13:06
    Using OBEX, it is so easy to add a VGA display and keyboard that it would make your head spin! And after all that, you still have six processors left to whatever you want.

    My first project was a kiln controller. It was ridiculous how quickly it went together and how little hardware it took other than the Propeller itself.
  • rearwheeldriverearwheeldrive Posts: 2
    edited 2010-10-21 18:59
    Thanks for the replies!

    Now waiting for the package from parallax to arrive to do my "hello world" led flashes. :)
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