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General LCD question — Parallax Forums

General LCD question

tobdectobdec Posts: 267
edited 2012-05-19 07:46 in General Discussion
Ive never programmed or hooked up an LCD in either parallel or serial on either the BS2 or my Prop. I was wondering if this would be simple to interface with either one since its basicly exactly what I wanted and a good price.

http://www.ebay.com/itm/Serial-Parallel-128x64-Dots-Graphic-LCD-Display-for-Arduino-AVR-PIC-White-Blue-/251051897547?pt=LH_DefaultDomain_0&hash=item3a73dbf2cb

Comments

  • Mike GreenMike Green Posts: 23,101
    edited 2012-05-18 12:59
    Anything that can be attached to an Arduino can probably be attached the same way to a Stamp or Propeller. You'll need a datasheet that shows you how to hook it up and describes the control codes. A serial connection would be the easiest to use.
  • tobdectobdec Posts: 267
    edited 2012-05-18 13:16
    I can get the data sheet with it I believe...that being said mike I think ill order one...or two thanks!
  • GordonMcCombGordonMcComb Posts: 3,366
    edited 2012-05-18 17:25
    The eBay page says 2 or 3 wire SPI (2-wire SPI is not typical; it probably means there's no slave-to-master data, and the slave select is always enabled). While SPI is indeed serial, it's not the more common and easier to use asynchronous serial used with serial LCDs. You'll want to use a Prop (or a BS2 if that's really your preference) with one of the SPI objects to facilitate communication.

    -- Gordon
  • tobdectobdec Posts: 267
    edited 2012-05-18 22:09
    Gordon im not against learning...however will useing an SPI from the OBEX bog down my Prop or is it pretty light weight?
  • GordonMcCombGordonMcComb Posts: 3,366
    edited 2012-05-18 23:43
    tobdec wrote: »
    Gordon im not against learning...however will useing an SPI from the OBEX bog down my Prop or is it pretty light weight?

    Not with eight cores to play with. Look for one written in PASM if you need the speed, but it's typically not critical for LCD, Unless you're doing animation. With plain text the data overhead is quite small. Both Spin and PASM versions come with the Propeller Tool, and I'm sure there are others in the OBEX if you want to experiment some more.

    Are you doing things in color or graphics? Consider a small LCD video unit -- one of those 3 or 4 inch jobs. A little more expensive than this LCD, but more colors. You can write text to it, animation, whatever. What Prop do you have? Some (like the Demo Board) have the RCA jack for video already on them. Even if your Prop doesn't have the jack, adding it and the the required three resistors is pretty easy.

    If this is for the big bot you've been talking about, look at Parallax's 7" LCD screen. Put the screen at kids' eye level. Children love "talking" to robots.

    -- Gordon
  • tobdectobdec Posts: 267
    edited 2012-05-19 01:27
    Ill definetly take a look at those written in PASM as opposed to spin. Yes Gordon its for our big one...however just for voltage of batts and temps and such. I do like the idea of an "actual" LCD that is capable of graphics and such...however ive got like 20 19" lcd displays just laying around that could easily be re-purposed. And I bought the 40 pin dip version so when the rubber meets the road im not stuck with a dev board like I am on my HW board.
  • tobdectobdec Posts: 267
    edited 2012-05-19 01:31
    Gordon is this the 7" Parallax LCD you are refering to?

    http://www.parallax.com/Store/Accessories/Displays/tabid/159/CategoryID/34/List/0/SortField/0/Level/a/ProductID/337/Default.aspx

    If so I would have to interface an rca jack for s-video output from my understanding this would consume alot of resources on any chip.
  • Invent-O-DocInvent-O-Doc Posts: 768
    edited 2012-05-19 02:08
    You can also find small NTSC video monitors on ebay for lesst than $20 that can be taken apart or buy them in kit form (www.brilldea.com) - That way you can use the video drivers for a much better display. That said, the SPI LCD display isn't a bad price if you don't mind waiting. It is large and appears to do some graphics, but may use custom commands.

    Typically, a parallel display that is harder to interface costs $8-14, serial displays are usually $10-12 more than that. (parallax has a simple serial unit for $25, sparkfun has them in a variety of colors for $25) Those standard serial units have objects for them in the OBEX.
  • GordonMcCombGordonMcComb Posts: 3,366
    edited 2012-05-19 07:46
    tobdec wrote: »
    Gordon is this the 7" Parallax LCD you are refering to?

    http://www.parallax.com/Store/Accessories/Displays/tabid/159/CategoryID/34/List/0/SortField/0/Level/a/ProductID/337/Default.aspx

    If so I would have to interface an rca jack for s-video output from my understanding this would consume alot of resources on any chip.

    That's the one. The interface is NTSC composite video. While it uses an s-video style connector, it comes with adapter cables. All you need is a 50 cent RCA-to-RCA cable to go from a breadboardable RCA jack (Parallax sells these) to the display.

    Resources: one cog, three pins on your Propeller. Each cog has its own video generator.

    Read up a little more starting here:

    http://www.parallax.com/portals/0/propellerqna/Content/QnaTopics/QnaVideo.htm

    -- Gordon
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