Hello,

Thank you for your post.

Could I ask what Display settings you are utilising for your LCD panel? and what system clock you have the BT815 running at?

Best Regards,
BRT Community

Hello,

I am new to working with an BT815 and consitently experience display artifacts when trying to display text in a custom font in a specific way. The font works properly as long as I only use a single font. As soon as multiple fonts are overlapping it starts flickering and displaying the artifacts.

I load the fonts from flash(glyphs in flash, xfont in ram_g) and set them with the EVE_CMD_SETFONT2 command.
All of the fonts are ~800KB in total right now(might be even more in the future), but still working on and finding new ways to make this less.

Since the code I use in the actual application is quite complex, I produced a minimal version of this, where this issue is still coming up:
    EVE_LIB_BeginCoProList();
    EVE_CMD_DLSTART();
    EVE_CLEAR_COLOR_RGB(0, 0, 0);
    EVE_CLEAR(1, 1, 1);
    EVE_VERTEX_FORMAT(0);

    EVE_CMD_TEXT(0, 0, NUNITO_SANS_32, 0, "Lorem ipsum dolor sit amet\n consectetur adipiscing elit. \nCras et lorem eget eros lacinia placerat.");
    EVE_CMD_TEXT(0, 0, NUNITO_SANS_24, 0, "Lorem ipsum dolor sit amet\n consectetur adipiscing elit. \nCras et lorem eget eros lacinia placerat.");
    EVE_CMD_TEXT(0, 0, NUNITO_SANS_32, 0, "Lorem ipsum dolor sit amet\n consectetur adipiscing elit. \nCras et lorem eget eros lacinia placerat.");
    EVE_CMD_TEXT(0, 0, NUNITO_SANS_24, 0, "Lorem ipsum dolor sit amet\n consectetur adipiscing elit. \nCras et lorem eget eros lacinia placerat.");

    EVE_DISPLAY();
    EVE_CMD_SWAP();
    EVE_LIB_EndCoProList();
    EVE_LIB_AwaitCoProEmpty();

But this is working
    EVE_LIB_BeginCoProList();
    EVE_CMD_DLSTART();
    EVE_CLEAR_COLOR_RGB(0, 0, 0);
    EVE_CLEAR(1, 1, 1);
    EVE_VERTEX_FORMAT(0);

    EVE_CMD_TEXT(0, 0, NUNITO_SANS_32, 0, "Lorem ipsum dolor sit amet\n consectetur adipiscing elit. \nCras et lorem eget eros lacinia placerat.");
    EVE_CMD_TEXT(0, 100, NUNITO_SANS_24, 0, "Lorem ipsum dolor sit amet\n consectetur adipiscing elit. \nCras et lorem eget eros lacinia placerat.");
    EVE_CMD_TEXT(0, 200, NUNITO_SANS_32, 0, "Lorem ipsum dolor sit amet\n consectetur adipiscing elit. \nCras et lorem eget eros lacinia placerat.");
    EVE_CMD_TEXT(0, 300, NUNITO_SANS_24, 0, "Lorem ipsum dolor sit amet\n consectetur adipiscing elit. \nCras et lorem eget eros lacinia placerat.");

    EVE_DISPLAY();
    EVE_CMD_SWAP();
    EVE_LIB_EndCoProList();
    EVE_LIB_AwaitCoProEmpty();

I found a Problem in the forum, which sounds like the problem I have, so the bandwidth could be the issue here(but the font loaded in that topic is way bigger, only a single font and the topic seemed stale - with a warning to post there):
http://www.brtcommunity.com/index.php?topic=298.0

The solutions over there did not work for me or are not feasible, more details to me trying out the solutions:
- turning on adaptive frame rate did not do anything, the display does not support it
- adaptive HSync is sadly not available on BT815
- loading the font from RAM_G -> I would like to avoid it, because I need to load a couple of fonts, which will use up too much space, because I also need a broad spectrum of characters for different languages and there are already icons in RAM_G to avoid this problem when loading icons/image.
- flash IC is already in FULL state
- switching to BT817 is not possible right now, too many devices to replace

I am very thankfull for ideas on how to handle this issue and maybe someone can verify this problem for me, just in case I was not smart enough to load the font properly or the issue lies somwhere else entirely.

Im still hoping I dont have to work around the issue, but we will see.

Best
Elmryn

Hello Rudolph,

Thank you for your post!

Certainly an interesting idea which we will pass along to the development team for review!

Best Regards,
BRT Community

I was just looking at what accelerometers are available on Mouser, sorted by price, as to detect the orientation of the display the simplest option should do.
And the most inexpensive option that is available today is a MXC4005XC with an I2C interface.

Then it hit me, EVE already is using I2C for the touch sensor.
And at least electrically it would be a no-brainer to add a second chip to the existing I2C bus, the only thing to look out for would be the chips adresses.
So what is missing in order to support an optional accelerometer is some software in the EVE chip to detect such an accelerometer on startup, read the registers if a accelerometer is present, calculate the orientation of the device from it and then provide the information in a register.

REG_ORIENTATION
Bit 2 – 0: screen orientation information bits.
0b’000: Default landscape orientation
0b’001: Inverted landscape orientation
0b’010: Portrait orientation
0b’011: Inverted portrait orientation

Well, maybe that is a dumb idea as I have no idea so far how complicated it is to implement this in software.
Hmm, I could add an accelerometer with SPI to my controller board for EVE,
this might be something extra to do untill BT820 are available to play with. :-)

Thank you for the confirmation, I will shuffle a few bits around in my library then. 

Hi Rudolph,

Yes you are correct, CMD_SYNC is available in FT81x and BT88x.

It must have been an oversight but our BRT_AN_088 covers both FT81x and BT88x from now on, to replace the FT81x programmers guide.

Best Regards, BRT Community

I am always looking for EVE modules to include support for in my library and I just found these from Winstar:

WF43WTYBEDST0 - 4.3" IPS 480x272 resistive touch, BT816
WF43WTYBEDSG0 - 4.3" IPS 480x272 capactice touch, BT815
WF50FSYBGDST0 - 5.0" IPS 800x480 resistive touch, BT816
WF50FSYBGDSGA - 5.0" IPS 800x480 capacitive touch, BT815

These might be Arduino shields and these might come in different versions.
Like with a SD socket, Arduino pins soldered in or a flash-chip - but none of these options are in the datasheets I found.

There is a 20pin header (FFC connector not populated) that looks like Winstar started with the pinout from Riverdi,
but pins 9 to 16 are different.
There is no Audio Out, the IOs are different and there are CSCL, CSDA, CRST and CINT pins for the ILI2130 CTP.

I wonder if the CTP is even connected to the BT815.

I am curious, but I can not find a distributor I would buy these from.
And Winstar only offers a short-form datasheet on their website.

Has anyone played with these?

Hello,

Thank you for your post, we will look to update the programmers guide accordingly.

Best Regards,
BRT Community

The BRT_AN_088_FT81x_BT88x-Programming-Guide.pdf v1.0 documents CMD_SYNC for FT81x and BT88x.
But the earlier FT81X_Series_Programmer_Guide.pdf v1.0 does not have this command.

Do FT81x have CMD_SYNC?

Edit: I guess FT81x do have CMD_SYNC, I just noticed that CMD_SETBITMAP is command #0x43 while CMD_SYNC is #0x42.
And #0x44 is CMD_FLASHERASE.
So not mentioning CMD_SYNC in the FT81x documentation is likely an oversight which has been correct with BRT_AN_088.

I just actually used CMD_SCREENSAVER and found a minor issue.
The command does not respect the setting of VERTEX_FORMAT and therefore requires to set it to 4 like this with the display-list macro command for it:

EVE_vertex_format(4);
EVE_macro(0);
EVE_vertex_format(0);

I am using a FT813 right now, a BT81x will probably do the same.
This was easy enough to figure out, the only issue is, this is not documented while at least for the BT81x commands like CMD_ANIMXY have a note in the programming guide.