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**ESPsupport** · 22nd February 2012, 06:24 AM

It sounds like your power supply is marginal.

How are you powering it?
if using USB and MB5/Cable increase the power to maxTry a different USB Port (and avoid HUBS)Use a good solid cable, some of the thinner ones cant manage more than 50ma or so

**HeliMan** · 22nd February 2012, 06:16 PM

My display is being powered by a 7805 regulator and this in turn is being powered by a 9V supply which can supply up to 10A! The regulator circuit is working fine and 5V is being applied to the display. I see that internally this is being reduced to 3.3V by your regulator. The display appears to be drawing about 200mA, but there are a few other ICs on the PCB too.

I will try a non-HC card to see if this makes a difference...

Dave.

**ESPsupport** · 22nd February 2012, 06:58 PM

Can you show a photo of how it's all connected together?

What sort of decoupling is on the 5v regulator?

The HC card should not make a difference, but how you have partitioned it might (Although it seems to work for some things

. Can you include the output from an msdos chkdsk command?

**HeliMan** · 23rd February 2012, 01:44 AM

Here is a circuit diagram...

The output measured at 4.9V, but the display has exactly 3.3V (measured).

Dave.
Attached files

**ESPsupport** · 23rd February 2012, 06:21 AM

How much wire is there between the 5v reg and the display?

The CID and CSD commands are only for testing. Have you tried DIR etc, without using them?

What about the output from the chkdsk command?

**HeliMan** · 23rd February 2012, 06:31 PM

The 5V reg is part of a PCB and the length of track between the Reg and the display is no more than 3inches. Every IC on the PCB is decoupled with 100nF Cap and there is a 100nF cap right next to the display.

Using FAT controller, I have turned off the display and its backlight. The DIR command is partially working. I have no folders on the uSD card and just 1 file - autoexec.4ds. The DIR command in FAT controller returns an odd string, somtimes I get: [email protected], and other times: EX.4DS and many other variations of the real filename. When I put the card in my PC it had another file with no name which I couldn't delete and the autoexec.4ds file had become corrupt. I assume the file with no name was from when I tried to copy the display to the card.

Also, can you please answer my earlier question: What do I put in the 'imagePos' field of command @6Dhex - Display image icon from card? If I have already specified the filename, why do I have to specify an address. I don't see how anyone would know the address location on a FAT memory card for a file?

I think that these displays are not as well manufactured as I thought. The touch screen doesn't work for about 10mm from the top and right edge in landscape mode and the uSD card has never worked, all that happens is the display corrupts the card.

I think it may be time for 4D to do a full review of this product as it obviously needs a major re-design. The PSU issue is not apparent in my design. I have checked the supplies (5V to display and 3.3V on the display) with a scope and they don't budge. Perhaps the memory card requires a larger capacitor next to it. You have a 100nF one there at the moment. Perhaps a 1uF or even a 10uF would help with current surges to the card?

Thanks,

Dave.

**ESPsupport** · 23rd February 2012, 07:12 PM

The uSD card is the most susceptable component to noise, its strange that you appear to be seeing the effects of a dodgy power supply without being able to fault it. Perhaps you can try again when you get the correct cable (refer to my response in your other post)

Have you done the chkdsk against the card yet?

The imagePos is the offset of the image within the file. You need to sue GC to build images for use on the display, it can put multiple images into one GCI file. If there is only one it will be at offset 0. You cannot display .BMPs (or any other format) directly.

As I understand it it is becoming very hard to source 3.2" touch screens that 'work properly'. However, given the granularity of general touch usage, and the usual positioning of 'touchables' away from the edges of the screen, the issue you are seeing is not generally an issue.

According to the circuit there is a 4.7uf across the output of the regulator and an additional 100nf at the uSD card socket.

**Atilla** · 23rd February 2012, 08:54 PM

I think that these displays are not as well manufactured as I thought. The touch screen doesn't work for about 10mm from the top and right edge in landscape mode and the uSD card has never worked, all that happens is the display corrupts the card.

I think it may be time for 4D to do a full review of this product as it obviously needs a major re-design. The PSU issue is not apparent in my design. I have checked the supplies (5V to display and 3.3V on the display) with a scope and they don't budge. Perhaps the memory card requires a larger capacitor next to it. You have a 100nF one there at the moment. Perhaps a 1uF or even a 10uF would help with current surges to the card?

We ship out over 1K display modules per week, do you think we'd be in business if the product was designed faulty? Everyone would be experiencing the same or similar problem. There are dozens of 4.7uf and 100nf caps distributed in bulk across the module, there's plenty of filtering. Having said that, there maybe a fault on your module, we're happy for you send it back and we'll do an extensive test and evaluate it, if it is faulty we'll cover it under warranty and have it replaced or fixed. Please contact support at 4dsystems dot com dot au and include a link to this forum post in your email.

As for the 100nf cap needing to be increased near the card, the answer is NO. The board is 4 layers, the internal 2 layers are used for 3.3V and GND and as per my statement above, there's plenty of decoupling bulk capacitance (some are close to the uSD) for power not to be an issue for the uSD. Hope this helps!!!!!

**meldavia** · 23rd February 2012, 10:37 PM

Dave,
your approach to getting help is far from acceptable.
As Atilla has said, this module has been in production for a long time now,
and there are thousands of users out there who are not experiencing your problem.
We do our best to sort out problems, whether it be hardware or software.

You mention in another post that you have more than 1 unit (purchased from Farnell)

First question is - is the same thing happening on both modules ?
Second question, are you waiting for the ACK or NAK before sending more data?

**meldavia** · 23rd February 2012, 10:43 PM

also, you mention 10mm - could it be possible that you are only reading the byte value from touch instead of the word value, and you are only getting a byte value which gives you a max of 255 ?

**HeliMan** · 27th February 2012, 06:49 PM

OK guys, I have now sorted the problem out. Windows Vista doesn't seem to want to format a 4Gb card to FAT16, even if I choose FAT it formats the card to FAT32. Also, even if I use the command prompt and format by using:

format g: /FS:FAT

I still get FAT32.

Thanks go to ESPsupport for suggesting the chkdsk command - that's how I realised that the card was still FAT32.

I am now using a 2Gb non-HC card and it is working. The dir command reports the correct file list and I have managed to copy the screen to the card and display the picture again

With regards to the touch-screen, I am copying the data as follows:
void GetGLCDTouchCoordinates(unsigned char Mode, unsigned int *buffer)
{
unsigned int Result = 0;
unsigned int x_coord;
unsigned int y_coord;

WriteUSART(0x6F);
while(BusyUSART());
WriteUSART(Mode);
while(BusyUSART());

while(!DataRdyUSART());
Result = ReadUSART();
x_coord = Result

**ESPsupport** · 27th February 2012, 07:09 PM

That's greate news!

You can always use RMPET to partition the uSD cards into to 2 Gig partitions (or whatever).

AN-1001 describes that in detail http://www.4dsystems.com.au/appnotes.php

XP will only format a 4Gig card natively from the command line, I assume Vista is the same in this regard.

Win7 will do it from the graphical format utility.

And that raises another issue, Win7 Changed the 'Trip' points for cluster sizes. Our PmmCs do not support 64k cluster sizes, so you need to drop the 'Maximum FAT16 Size' %age created by RMPET until you get a 32kb cluster size in Win7. Will be fixed at some stage.

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