Re: Microcontroller with QVGA or VGA LCD controller

"Trev16v" <t@xxxxxxxxxxxxxxxxxxxxxxxxxx> skrev i meddelandet
news:JaadnU4-PN_XsFbanZ2dnUVZ_rignZ2d@xxxxxxxxxxxxxxx
This is an interesting discussion because I'm also trying to put together
an ARM-based device with a 320*240 TFT. It is a hobby project but I do aim
to produce a number of them if all goes well, so I need a cheap design and
I don't want to use anyone else's modules. Having spent many hours looking
at ARM devices from Sharp, NXP, Atmel and so on with integrated
controllers
and ended up rejecting all of them either because they're BGA, or because
I
can't get the devices easily or have fear of them becoming obsolete
(especially Sharp) or various other reasons, I have decided to fall back
on the old faithful solution which is to use an Epson controller together
with an ARM that has an EMI.

In fact my prototype at the moment is an STR710FZ2T6 together with not an
EPSON device, but instead a Solomon SSD1906. I don't think that anyone has
mentioned the Soloman parts yet but they appear to be the Epson parts that
have been rebranded and repackaged. Maybe someone can tell me more about
this.

Why not an AT91SAM9260?
TQFP and 200 MHz...
Should leave an ARM7 in the dust...


I went for the Solomon device because it's easy to get hold of in the UK
to make a prototype. Rapid Electronics and RS over here actually stock it.
To get an EPSON S1D device I'd have to make an expensive order from
Digikey
in the US.

The STR710, SSD1906, plus the flash and RAM is quite a nice cheap solution
I think.

I have personally already worked with the EPSON S1D devices in the past,
by the way. Several years ago where I used to work I did a design using
the S1D13705. I found it really easy to use. I didn't use any of EPSON's
software. I just used the data*** and wrote my own routines and so on.
That design used a PIC18F8720! I guess the slow response and blurryness of
the STN panel we used sort of disguised how slow the graphics were :-)
That
product is still being sold by the company, so maybe I could try to sell
them an improved ARM version...

Now for a question:

For those who have already used an EPSON or similar device with an ARM
controller, what kind of speed of graphics can one achieve assuming, say,
anything from a 320*240 to a 480*640 VGA panel? Assuming an ARM7 and
S1D13705 or similar, can anything near to streaming video be achieved?


Not a chance...
Not even an ARM9 is particularily good.
Some people may have noted the new crop of ARM9/ARM11 with
Video accelerators.

An AVR32 can do QVGA in S/W, but you can only get them in BGA package.
There is a cheap board, the AT91NQW100, but that only has
a 16 bit SDRAM so performance is a little thinner.
On the other hand, the AVR32 can do QVGA video at 75 MHz
with a 32 bit bus, and IIRC, the NGW100 runs at 150 MHz.


Cheers

Trev



--
Best Regards,
Ulf Samuelsson
This is intended to be my personal opinion which may,
or may not be shared by my employer Atmel Nordic AB


.