Proppad LCDboard now @ 100Mhz, flicker free flying 3D, faster image loading and more
tripp
Posts: 52
Hi all.
I have spend some time with my proppad,and made some improvments.
Now running @ 100Mhz with this new crystal 25.000Mhz crystal with _CLKMODE = XTAL1 + PLL4X
The 3D demo is now moving... sourcecode here: LINK
Image slideshow is faster, but it can get even faster with more PASM, but iam still lerning.
Text mode is really fast and changing backgroud color is superfast.
The 25Mhz crystal is working stable, but i wonder is it better to run 6.25*16PLL or 25*4PLL?
Here is a new video running the new demos: http://www.youtube.com/watch?v=8XbwVrU-yqg
You can download the sourcecode here:
http://www.xtune.se/product_info.php?products_id=131
And i have the bare proppad PCBs on sale @ USD 2.41 now!
http://www.xtune.se/product_info.php?cPath=40&products_id=130
Here is some new pictures:
I have spend some time with my proppad,and made some improvments.
Now running @ 100Mhz with this new crystal 25.000Mhz crystal with _CLKMODE = XTAL1 + PLL4X
The 3D demo is now moving... sourcecode here: LINK
Image slideshow is faster, but it can get even faster with more PASM, but iam still lerning.
Text mode is really fast and changing backgroud color is superfast.
The 25Mhz crystal is working stable, but i wonder is it better to run 6.25*16PLL or 25*4PLL?
Here is a new video running the new demos: http://www.youtube.com/watch?v=8XbwVrU-yqg
You can download the sourcecode here:
http://www.xtune.se/product_info.php?products_id=131
And i have the bare proppad PCBs on sale @ USD 2.41 now!
http://www.xtune.se/product_info.php?cPath=40&products_id=130
Here is some new pictures:
Comments
as already noted by mpark, 25MHz is out of spec of the PLL, so there is a good chance that it won't work with all propellers or might get broken after a while?! It's better to use the 6.25 MHz chrystals.
I still don't understand why loading the images is so slow! I have a similar display (320x200x24) with an 8 bit interface and it loads an image in 625ms from SD-card. In 16 bit color-mode it's even faster. If you send me one of your displays I'll adapt my driver to work with your display ;o)
Indexed colors means that you can select 4 or 16 colors of the full 24bit color-space.
Reading images is done by some modifications in FSRW, so that both drivers work together very good. (FSRW does not store the image but takes over the control of the display and directly sends the data to the display). Unfortunately it's not the latest FSRW, so this should maybe be redone with a newer version.
Planning was to use the buildin fonts as well, so that bigger text is available.
Where do you get the displays and how much do they cost? (Just thinking with all the work trying to get 64 colors to look ok, maybe it is better to use a commercial 24bit solution as you have).
http://www.xtune.se/product_info.php?cPath=21_35&products_id=111
It depends on what you want to do with the display. You can do animations in small areas if you store em on SD-card. If you have to read back content of the screen-buffer things get really slow. So, I'd recommend not to to image processing.
But with some nice tricks you can have a real good user interface. I used a similar display for this: http://forums.parallax.com/showthread.php?117190-SPFD5408B-display-driver-(320x240x18)
I see some economies of scale with these things with the price rapidly falling. eg, buy the display by itself for $60 http://www.csmicrosystems.com/products/17-28-tft-color-lcd-240-x-320-pixel.aspx or get on ebay and buy a touch screen MP3 player with a video camera and the display for only $34 http://cgi.ebay.com.au/2-8-4G-LCD-Touch-Screen-MP4-MP3-FM-MEDIA-PLAYER-/250726101855?pt=AU_Car_Parts_Accessories&hash=item3a6070b35f
I'm wondering what you could do with animations if you combined this with external ram? 512k of ram space to play with - do the processing in propeller code and send it to the display when it is done.
I see the code for this display is open source. The dracblade with external memory is all open source as well - see my link at the bottom of this post. I've not looked at surface mount but it certainly would make things smaller - probably about a quarter of the board size. 3 latches and the 512k ram chip. And you would save on propeller pins as the 8 pins used to drive the VGA screen could be used to drive this display and with some pins left over. Speed would be fast if the LCD driver were in the same cog as the ram driver and there ought to be room in a cog for both.
If you had touch screen maybe you don't even need the keyboard?
Some very interesting possibilities!
18bit interface could be possible. The latch driver for external ram uses 12 propeller pins - 8 for a data bus and 4 for driving a HC138. There are 8 outputs from the 138 and 3 are used for the ram chip so you have 5 left over. You can easily add more latches - so if you added another 3 latches you can drive an 18 bit parallel display if you like. I spent a little time looking at displays. Some have easier connections than others. There is one with a 40 pin connection. I think there are serial and parallel ones?
addit $28 on ebay with free shipping. http://cgi.ebay.com/3-2-TFT-LCD-Module-Display-Touch-Panel-PCB-adapter_W0QQitemZ200475566068QQcategoryZ26206QQcmdZViewItemQQ_trksidZp4340.m8QQ_trkparmsZalgo%3DMW%26its%3DC%26itu%3DUCC%26otn%3D5%26ps%3D63%26clkid%3D5932934938160254089 and the touch screen as well.
You could draw a little keyboard on that screen...
Worth hunting around for these LCD displays. 160x128 full color on board memory for $4.99 including shipping http://cgi.ebay.com/1-8-TFT-Color-LCD-Module-Display-build-in-HX8310-/190478589479?pt=LH_DefaultDomain_0&hash=item2c59689e27
Do you want me to send you a PCB and a LCD for free, i can also send a usb mini connector and the L2 component.
Here is the schematic: Schematic.pdf
JPG, BMP, TIF, RAW ??
240x320 ?
8bit, 16bit, 24bit, 32bit ?
/n.