Sparkfun's "Huge" LCD working with Prop

Rayman

I just got this very nice LCD going with the Prop!

It's a 5V device, but I've connected all the I/O pins directly to the Propeller (even without resistors) and it works.

I've made some notes on it here:
http://www.rayslogic.com/propeller/3rdPartyHardware/3rdPartyHardware.htm

It has 32kB of memory and a built in font, so it can store many, many pages of text that can be instantly switched between or vertically scrolled.

It has an independent cursor, that could be very nice for terminal apps.

There's also a graphics mode, but I haven't really played with that yet.

My driver is currently all in Spin...

Check out this photo (It's a very pretty display, even though monochrome):

Update:· I now have the code working good enough for my needs.· Added set and clear pixel routines for the graphics screen.
So, I'm posting the code here:


Post Edited (Rayman) : 11/24/2008 1:40:56 PM GMT

JerryN

Good going! I am about ready to get mine fired up and appreciate the information on the data bus. I plan to write the drivers in assembly although I might do it in spin first just to get things working.

No resistors on the data lines? I was going to put some in to avoid overdriving the Prop ports when reading the status of the LCD.

Jerry

Rayman

I would probably recommend using 1k resistors...· I tested it that way too.· But, I didn't have space for them on my board, so I'm going without.

Dennis Ferron

Is this LCD still readable with the back light off? I'm looking to make an ultra-low-power laptop using Linux on a GumStix ARM board + a Propeller as a serial terminal. I hadn't been able to find a display; it looks like this might be the solution. Thanks for posting this!

Rayman

I didn't try it without the backlight...

Ariba

Dennis

Maybe this is a display for you:
www.knjn.com/image.php?img=ShopItemsPics/LCD480x320%20xylo.jpg&title=Graphic%20monochrome%20LCD%20panel

Andy

Rayman

My driver is in pretty good shape now... Works well enough for my needs (but could be much faster if converted to assembly). I've posted the driver and test app in the original post...

Rayman

Just got my "mini-Marx" controller boards in from ExpressPCB and the display part of it works perfectly.· Should give a jumpstart to anyone wanting to make a custom board for this display...

The board files are here:

http://www.rayslogic.com/propeller/PropPCB/PCB_Boards.htm

Only mistake I made was putting in the power plug jack upside down...· The side hole should be above the main terminals, not below.· Not too much of a problem because I'm not using that pin anyway.· I just drilled a new hole for it, but could have just cut of the third terminal from the power jack.

Rayman

Here's a photo of the board with just the stuff to make the Prop and the display work:

Rayman

Ooops. Found a couple major problems with my board... One interesting thing is that I had 5V accidently hardwired to the 3.3V Prop power and yet it was somehow still working for a few hours... But, it eventually killed the Prop and the EEPROM too [noparse]:([/noparse]

I've made notes of the problems on the web site above, just in case anybody was (silly enough [noparse]:)[/noparse] to use that design...

Oldbitcollector (Jeff)

@Ray:

Please clarify: Was that an issue of drawing the 5v power from the Prop 3.3 or the datalines?

Sounds like if you power it directly from the 5v regulator life is good..

OBC

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GreyBox Tim

Dennis Ferron said...
Is this LCD still readable with the back light off? I'm looking to make an ultra-low-power laptop using Linux on a GumStix ARM board + a Propeller as a serial terminal. I hadn't been able to find a display; it looks like this might be the solution. Thanks for posting this!

Hey Dennis - If you want to do a super low power display, check this out: http://www.kentdisplays.com/products/glass/640x480.html·(Kent Displays 640x480 Cholesteric Display Module with Integrated Controller)

Kent does "No power" displays, as it only uses power to update the display, but afterwards, the control logic can be either powered off completely while the image stays on the screen or put in a <6uW standby (to keep the display memory alive).· If you think that's cool - they also came out with something they call "eGo" which is a surface "skin" you apply to your product - and you can electronically update the skin's color (like adaptive camoflage).· they are also currently working on flexible full-resolution displays that can be integrated into fabric so that you can change the pattern of the logo or on a shirt something like that.

-Tim


Post Edited (GreyBox Tim) : 12/17/2008 7:55:01 PM GMT

mikediv

Rayman can I ask you a few questions? I just splunked down the 60 bucks for this display but I noticed you have a differant board than me I have the propstick usb educational board but I also wire wrapped up another of my own design with a proto board and a 40 pin prop with serial interface. it should work just the same right? I just want to be able to send debug info or data aquistion stuff out to the display would you recommend this one ???

thank you for the code looks good

ooops I hope I didnt screw this up but this is the only thing you need right? I ordered the big lcd kit from the link but do I need anyhting else beside a prop board? I mean beside the resistors and stuff is everything I need to hook the display up to my propeller chip included with the lcd or did I need another daughter board?



Post Edited (mikediv) : 12/17/2008 11:40:05 PM GMT

Rayman

OBC:· I had the Prop's Vdd connected to +5VDC.· (I didn't think it would work at all that way, but it seemed to work for a little while at least...).

mikediv:· You need one potentiometer to adjust the contrast, one capacitor to keep the reset line low for a microsecond or two, and a 5VDC supply.· All other lines connect directly to the Prop.

mikediv

Thanks Rayman I went ahead and ordered mine and thank you for the driver cant wait to get it hooked up
did anyone try and do graphics with yet or just text?

Rayman

My driver can do lines and set pixels in the graphics memory... It'd be easy to do more, but it works good enough now for my needs...

Invent-O-Doc

I've looked through the driver code and it looks great. Just got the display in the mail. One thing that confuses me in the driver documentation is the pin hookup; I can't figure out where to connect the data pins. Can somebody provide some clarification or a schematic view?

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Thomas Talbot, MD
Gunpowder, MD, USA

Rayman

Well, since you have the driver, you can look at this page:

http://www.rayslogic.com/propeller/PropPCB/PCB_Boards.htm

to see my board and see pin-for-pin how it is connected...

Ale

I'm using a similar display but I keep a bitmap in memory (240x64) and write to it directly, a separate COG refreshes the display every 50 ms. Mine is a 5V part so I'm using some HCT buffers with series resistors, it works great. Somo other 128x128 displays need negative bias :-(, problematic.

Rayman

This is also a 5V part!· But, it doesn't seem to mind being connected directly to the Prop...

mikediv

Rayman I hope you dont mind me asking you some more questions I have not got my display in yet but I went ahead and downloaded the pcb software very cool by the way and I intend to have some circuit boards made myself , but as to connecting to LCD to the prop I am not seeing how or where can you tell me what pins to plug into the prop to the display and do I have to buy the board you show on their website??? or have it made and buy the ADC and other componets. sorry for all the questions I should have understood before I went and ordered stuff ,· the only thing I bought from sparkfun was the LCD well some other Smile but nothing to do with your post so I guess in a nutshell can this LCD just be connected to the prop board or did I miss somehting entirley , I was able to open your file and it showed me the circuit board but no pins or parts list again sorry for all the questions
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Rayman

I suppose the easiest and lowest cost way for you to get started is to get a Protoboard. That can be connected directly to the display as I show in the picture in the first post in this thread...

The pins on my board are arranged exactly the same way as the pins on the display...· The square pad indicates pin#1 on both...