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Small TFT display question — Parallax Forums

Small TFT display question

grasshoppergrasshopper Posts: 438
edited 2008-07-31 00:47 in Propeller 1
I am new to implementing displays, i have had great luck running VGA displays and 2x20 lcd displays using my propeller, but what about this one

search.digikey.com/scripts/DkSearch/dksus.dll?Detail?name=73-1325-ND

or this one

www.newhavendisplay.com/pdf/nhd-18-128160yf-ctxi-drawing.pdf

I need a small color display for my new propeller project. Ideas and comments are greatly desired.

Comments

  • AleAle Posts: 2,363
    edited 2008-07-24 16:49
    The power supply is a bit complicated, it needs some level shifter, the three colors as 6 bit quantities, and is only available if you buy 1000 ! :-/... well if you can cope with that...

    Edit: The other one, 128x160 seems nice, a bit small... but if you get the programming of the controller... and it costs some 10 to 20 € each, it may be a good candidate.
  • Mike GreenMike Green Posts: 23,101
    edited 2008-07-24 16:50
    Neither of these appear to have a controller. The 2nd one has no interface information. The 1st one looks like it needs a lot of "care and feeding". You definitely don't want to start with these unless you're a "glutton for punishment" and a "strong self-starter".

    How about one of the 4D Systems OLED displays? You could even combine the Propeller with the display by using the uOLED-96-Prop (for $80 including a memory card socket).

    One other option might be to get a cheap small LCD TV monitor and use the Propeller's TV drivers.
  • grasshoppergrasshopper Posts: 438
    edited 2008-07-24 17:15
    Well I am no gluten for punishment unless forced to be such A.K.A the boss makes me design using one. I did see the 4D system but kind of wanted to learn this on my own accord. Opps i see they sell displays tongue.gif edited**

    Mike you mentioned a small LCD monitor where can one be purchased? Ill start searching but perhaps you'll have some inside information.
  • Mike GreenMike Green Posts: 23,101
    edited 2008-07-24 17:23
    Parallax sells one, but they've recently switched from a 2.5" device to a 3.5" device and they're out-of-stock on the new one. I don't have any magic links. I'd probably just start web-surfing.
  • grasshoppergrasshopper Posts: 438
    edited 2008-07-29 21:30
    Well i found this little display and was wondering if it is as easy to hook up as it appears?

    www.sparkfun.com/commerce/product_info.php?products_id=569

    I am still new to this kind of display, but want to run something like this with my propeller all the advice I can get would be great

    Thanks
  • KamPuttyKamPutty Posts: 48
    edited 2008-07-29 22:39
    Grasshopper,

    I have that display that I have working with the PIC...nice display, but it is slow.
    Let me know if you get it, I can send you the code to make it work (you can refactor to spin)

    ~Kam (^8*
  • grasshoppergrasshopper Posts: 438
    edited 2008-07-29 23:44
    KamPutty said...
    Grasshopper,

    I have that display that I have working with the PIC...nice display, but it is slow.
    Let me know if you get it, I can send you the code to make it work (you can refactor to spin)

    ~Kam (^8*

    What do you mean it is slow? I mean, is it not the processor that determines the speed in which the display can be run at? If i am to run the propeller would this still mean it is slow how fast is the PIC? Perhaps you could some how bring me up to speed on the issue of "slow". No pun intended.

    Also; I appreciate your help. I plan on ordering it as soon as I feel that it will fit my new project.

    Edited ** - Could you post some pictures so that i could see the quality of the display?
  • KamPuttyKamPutty Posts: 48
    edited 2008-07-30 01:20
    Hi there,

    It's slow in regards to the update speed. I think it has 2 modes (I worked with it 2 years ago), serial and parallel...I could be wrong about the parallel. I used the serial, bit banged the data thru. But if you're not doing "graphics" it should work fine...

    Pics...hmmm, I'll have to take the pic out and reburn the code!

    From what I recall, the actual brightness etc was really good,it's just the speed...said that, I was comparing the speed with an oled display...
    I personally would use the display if I where doing text *ONLY* (I don't think it displays 'graphics')

    ~Kam (^8*
  • Timothy D. SwieterTimothy D. Swieter Posts: 1,613
    edited 2008-07-30 02:31
    If you search around the forums and on the object exchange I think you will find that others have also used this display. You can do some graphics, but it will be limited because the Prop doesn't have enough memory to do hi-res bitmap graphics.

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    Timothy D. Swieter, E.I.

    www.brilldea.com·- Prop Blade, LED Painter, RGB LEDs, uOLED-IOC, eProto fo SunSPOT, BitScope
    www.sxmicro.com - a blog·exploring the SX micro
    www.tdswieter.com
  • grasshoppergrasshopper Posts: 438
    edited 2008-07-30 04:40
    Timothy D. Swieter said...
    If you search around the forums and on the object exchange I think you will find that others have also used this display. You can do some graphics, but it will be limited because the Prop doesn't have enough memory to do hi-res bitmap graphics.

    Well as far as graphics what am i limited to? Can I make a clock or a gauge for example to show volts or RPMs? A primitive tachometer perhaps? Sounds like I could.

    As far as you mentioned, I will search the other threads to see what is out there.

    Thanks again. tongue.gif
  • Timothy D. SwieterTimothy D. Swieter Posts: 1,613
    edited 2008-07-30 08:45
    Yes, I think you will be able to do limited graphics and limited color depth. The first thing you will need to do is write a driver for the display. Actually, the driver may exist in the object exchange or in other threads. The driver should clock pixels out to the display. Next you need to setup a "video memory" where the LCD driver gets the data from and clocks it out to the display. Then attach a graphics driver to fill the video memory. If you work things out right, you might be able to use the graphics object that Chip created and save you the trouble of writing a graphics driver.

    On the uOLED-96-PROP I create a driver in ASM for the display. The standard graphcis driver could be used to paint images and text on the display. When I created an 8-bit per pixel OLED display driver, I had to reorganize the video memory and write a new graphics driver.

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    Timothy D. Swieter, E.I.

    www.brilldea.com·- Prop Blade, LED Painter, RGB LEDs, uOLED-IOC, eProto fo SunSPOT, BitScope
    www.sxmicro.com - a blog·exploring the SX micro
    www.tdswieter.com
  • grasshoppergrasshopper Posts: 438
    edited 2008-07-30 20:34
    Ok based on your reply I ordered a display form spark fun and a few connectors. Ill keep this thread alive with my progress and questions, so stay tuned. Thanks
  • Timothy D. SwieterTimothy D. Swieter Posts: 1,613
    edited 2008-07-31 00:47
    Great - I hope the project turns out well. I know there has been discussion about the different display chips used in these connectors. Be sure to read through the data found in the other threads and on Google searches.

    Lets do a little math. I assume you can use the graphics library and create a LCD driver that is similar to the TV driver. By similar I mean that you can use tables for color pallete. Do you have a Hydra Book? if not, I recommend getting one because it goes through these design very well.

    OK, with the graphics driver each pixel is 2 bits. That is there are four possible colors, more if you work with tables and create another redirection. For now lets stay simple. 2 bits per pixel is 16 pixel per long (a long being 32 bits). The SparkFun screen you reference is 128 pixels x 128 pixels. That is 16384 pixels. Divide by 16 to get the number of longs needed for a single video buffer. That is 1024 longs for a single video buffer. If you are doing animation or multicogs then you might want to double buffer the animation.

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    Timothy D. Swieter, E.I.

    www.brilldea.com·- Prop Blade, LED Painter, RGB LEDs, uOLED-IOC, eProto fo SunSPOT, BitScope
    www.sxmicro.com - a blog·exploring the SX micro
    www.tdswieter.com
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