Author Topic: LPC24XX with LCD  (Read 15517 times)

Offline mark

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LPC24XX with LCD
« on: June 21, 2009, 03:18:21 PM »
Hi All

A new service pack (in fact an official release of the complete LPC2xxx project) is waiting in the wings, so it is time to mention a few details.

The single project includes support for all devices from LPC2101 up to the LPC2478. Support of the LPC24xx is new, although not basically that different from the LPC23XX at the driver level. What I do like about this is the breadth of the chip's compatibility. The demo project will compile a wide variety of features up to TFT display (see below for more details) when configured for the LPC2478FBD208, but will still compile for the baby in the family (LPC2101), with of course a few less features. This makes it so easy to chose one of the chips which is optimal for a certain application and immediately start running the code on it.

The most interesting about the new member, the LPC24xx, is that some of the devices include LCD controller. Together with its SDRAM controller and external interface, quality graphics and display based control becomes very easy to work with. The uTasker simulator is ready to allow complete simulation of this and makes development even easier and more fun.

To whet your appetites, check out the new simulator screen shots with graphical LCD/TFT support at http://www.utasker.com/Demos/Simulations.html

Also the LPC2478 is online at the moment at http://demo.utasker.com
The demo contains a TFT page which displays the present screen image (this uses dynamic content generation and builds a BMP from the image and sends it to the web browser - the code size to do this is in fact about 25 lines - including comments! It was developed in the simulator and worked first time on the target - as one would expect ;-)

It also allows posting new images to the board (a sort of LCD picture frame which can be updated by anyone via the Internet). Note that the Ethernet reliability is not 100% as discussed here: http://tech.groups.yahoo.com/group/lpc2000/message/42719 It is hoped that the reason can be identified very shortly (there may be a HW problem with the board (?)).

But this leads also to a general question. What about LCD support in the project? This has been looked at with a lot of experimental work during the last couple of months and the next SPs will in fact all contain monochrome graphic LCD support (via parallel port) with font and image capabilities. Furthermore SPI based controls and color graphical LCDs will also become supported as standard (but not necessarily in the next SP) . The new LPC2XXX package will be a bit of an exception due to its TFT support but this is more due to the fact that it would be a shame to run code on the LPC2478 board without being able to use the great display. Graphic libraries will however be missing in this version.

So what about graphic libraries? Well the first thing to say is that the actual control technique is rather different for various LCD types. A chip with inbuilt LCD controller is in fact the easiest to work with but the images are quite big (several hundred kByte is easily possible) which is not always practical to backup in SRAM! Mono-chrom LCDs need maybe 1k and so intermediate buffer techniques are interesting. This does however make things more difficult to standardize. What one finds is that there are usually graphics libraries supplied by the semiconductor manufacturers too. These are however restricted to use in projects with the specific chips and not compatible between each supplier. They can be used but don't allow flexibility in moving to other chips and projects, so this is a reason why a uTasker graphics library will also be added over time. The big advantage of the uTasker project being also that all work is much easier in the simulator - whether using a manufacturer's library or ultimately the uTasker graphics library the simulator will make life easier during real development.

Regards

Mark

PS. The LPC24XX is a big chip. However the demo project (as online) occupies about 64k program code pace and uses (only) around 20k of the available 96k SRAM!



Offline jezc

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Re: LPC24XX with LCD
« Reply #1 on: July 07, 2009, 10:30:03 PM »
Hi Mark,

I have access to the Olimex 2478 board (badged as IAR) through work - if you still need someone to try running the code as a comparative test, please let me know!

We also have two other board types with the LPC2478 fitted (an Embedded Artists 2478 board and another board by Future Electronics) so if there are problems with the Olimex one, we should be able to compare the performance/behaviour with one of the other designs.

I'd be very interested to hear when you actually release the full NXP version!

Cheers,
    JezC

Offline mark

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Re: LPC24XX with LCD
« Reply #2 on: July 13, 2009, 11:17:39 AM »
Hi JezC

The uTaskerV1.4 packet is presently being prepared for release. Since I am away until the 24.7.2009 I am using this time to get documents together and doing as much general tidying up as possible. There is certainly a problem with the LPC24XX Ethernet when serving larger images and I also can't exclude something similar on the LPC23XX as the last time I check it it was also not behaving that well; compiling with a different compiler seemed to cure this (on the LPC23XX) but I may have then tested with smaller images so the comparison was possibly not correct.

Anyway I decided to concentrate efforts on the new package generally - there are a lot of new features requiring new documents etc. - since tests have not show similar weaknesses on the other processors. Once the uTaskerV1.4 is released I would then focus on finding out what is up with the LPC Ethernet connection and attempt to patch this asap.

In the meantime I will send you an image for the LPC2478 with web pages (to load) plus a couple of bit maps for the TFT. In my experience it is basically working but has some difficulty displaying the display content in the web side [it may do it fine once or twice but will then be very slow or give up on the next attempt]. I don't expect a HW problem but if you could check on your board it would be useful to be absolutely sure.

Thanks!

Regards

Mark

PS. I will get a small test package ready later today...



Offline jezc

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Re: LPC24XX with LCD
« Reply #3 on: July 13, 2009, 09:43:03 PM »
Hi Mark,

We're planning to use a range of NXP processors in our work projects so we'd like to be sure that there aren't any general problems with ethernet, so helping prove where the problem lies would help us both in the long run!

But for now, I'm primarily looking at the NXP port out of personal interest (to compare it with the Kirin 3 port on a price/performance basis).

We're also looking at the new LPC17xx family devices which I'm sure you'll be supporting soon?

Just let me know what you'd like me to check (and whether it's worth checking on say the Embedded Artists board as well as the IAR//Olimex one) and I'll feed back my results as soon as I can. Obviously, to try it on both boards would probably require me to register for the NXP so taht I can access the source - I will do this as soon as it's necessary if that's ok?

Cheers,
    JezC

Offline RogerH

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Re: LPC24XX with LCD
« Reply #4 on: September 20, 2009, 04:55:25 AM »
Hi Mark,

Not working for me on my Olimex LPC2478-STK or the simulator as per my other post.

On the hardware, it is mostly running except the webpage has the uTasker background and the forground text is garbage and hangs my browser.

FTP to the board produces the following:

C:\Documents and Settings\Administrator>ftp 10.10.10.100
Connected to 10.10.10.100.
220 Welcome LPC23XX FTP.
User (10.10.10.100:(none)):
331 Enter pass.
Password:
230 Log OK.
ftp> dir
200 OK.
150 Data.
-r-xr-xr-x 1 502 502 1150 May 1 2009 favicon.ico
-rwxrwxrwx 1 502 502 344059 May 1 2009 B.???
226 OK.
ftp: 96 bytes received in 0.17Seconds 0.56Kbytes/sec.
ftp>

If I upload via the DOS Copy_All batch file the upload appears to be happening, but a ftp>dir shows no change in content on the board.

I hope that we can solve this one as I am dead keen to get this running and findout all the good stuff that uTasker has to offer.

Cheers, Roger...



Offline mark

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Re: LPC24XX with LCD
« Reply #5 on: September 20, 2009, 12:47:06 PM »
Hi Roger

Looking at the line in the DIR:

-rwxrwxrwx 1 502 502 344059 May 1 2009 B.

there seems to be something in the file system memory which is being recognized as a large file.
This may be something already in memory when you programmed the device.

The file system assumes that the FLASH is initially blank so may get confused if this is not the case, which can also lead to it making an error, leading to a reset (and hang of any FTP connection).

If you connect to FTP and command a DEL *.* this will cause a delete of the file system space (afterward you should see only the favicon.ico [fixed in use file system]). With a clean file system space you should then be able to start working "normally".

Regards

Mark