BRT Community

This issue just came back to me: https://github.com/RudolphRiedel/FT800-FT813/discussions/163

I reduced my display list to this:

EVE_cmd_dlstart();
EVE_clear_color_rgb(WHITE);
EVE_clear(1, 1, 1);
EVE_tag(0);
EVE_color_rgb(BLACK);
EVE_cmd_number(100, EVE_VSIZE - 65, 26, EVE_OPT_RIGHTX, cmd_fifo_size);
EVE_cmd_number(100, EVE_VSIZE - 50, 26, EVE_OPT_RIGHTX, display_list_size);
EVE_cmd_number(104, EVE_VSIZE - 35, 26, EVE_OPT_RIGHTX|6U, num_profile_a);
EVE_cmd_number(104, EVE_VSIZE - 20, 26, EVE_OPT_RIGHTX|6U, num_profile_b)
EVE_display();
EVE_display();
EVE_cmd_swap();

And with EVE_cmd_setrotate(0); the text is fine, with EVE_cmd_setrotate(1); it is barely readable.
With EVE_cmd_setrotate(2); it is fine.

The display settings I am using:
#define EVE_HSIZE (1280L)
#define EVE_VSIZE (800L)
#define EVE_VSYNC0 (0L)
#define EVE_VSYNC1 (10L)
#define EVE_VOFFSET (23L)
#define EVE_VCYCLE (838L)
#define EVE_HSYNC0 (0L)
#define EVE_HSYNC1 (20L)
#define EVE_HOFFSET (88L)
#define EVE_HCYCLE (1440L)
#define EVE_PCLK_FREQ (0x08C1U) /* value to be put into REG_PCLK_FREQ -> 72MHz, REG_PCLK is set to 1 */
#define EVE_SET_REG_PCLK_2X
#define EVE_PCLKPOL (1L)
#define EVE_SWIZZLE (0L)
#define EVE_CSPREAD (0L)
#define EVE_HAS_CRYSTAL
#define EVE_GEN 4
#define EVE_BACKLIGHT_FREQ (4000U)


Is there anything I can do to fix this?

To add a minor detail, FT8xx and BT81x "only" support 32 bitmap handles, so 0 to 31.
15 is used as a scratch bitmap by a couple of commands.

BT82x has 64 bitmap handles and 16 to 34 are assigned to the fonts.
Unfortunately it still uses the same fonts, but at least there are all directly useable.

Just saw that EAB 4.1.0 is finally: out https://brtchip.com/eab/

While that is impressive, that does not really solve the availability of BT82x modules.
Yes, buying panels turned out to be a pain by itself, but usually that is a problem that can be solved with throwing money at it - thinking about single units here for evaluation or to play with, thinking in production level amounts I would send a suit from procurement to get me what I want (and I wish I was there).

However, the fun starts when adapting the panel to the VM820C - and the touch.
That is why I am also thinking about designing a board for the MN820.

So I prefer integrated modules.
And based on the experience with the VM820C so far, I would go for the option with 1GBit DDR3L and even no external flash (the option to solder a SOIC-8 would still be nice), as long as there is a micro-sd socket.

So, I got myself a ACD-110DHTT which is a 10.1" industrial touch monitor that I got used for only 23€ from
EBay, 1280x800.
The panel is a G101EVN01.0 from AUO, LVDS, single channel, 6 bits per color.
The display was fairly easy to adapt to the VM820C, but I gave up on playing with the eGalax touch controller.
I bought a 10.1" touchscreen digitizer on EBay for €6.99, I selected this one for clearly having a controller chip visible on the supplied fotos, although I could not identify the specific chip.
Some other parts that are sold do not have a touch controller integrated and apart from no chip visible these have way more pins on the cable than the 6...12 you will find with a touch-panel + CTP combi.

The one I bought was advertized as replacement part for a "ICOO ICOU10G 10.1 inch" tablett and also is labeled as "ENERGY Neo" - getting of one of these tabletts might be interesting.

Anyways, the digitizer arrived and the touch chip turned out to be a FT5506 - bingo.
I used a 12pin FPC adapter to connect to CN8 on the VM820C.

Oh, btw., the 7" I was using before had a FT5316.

Unfortunately the touch digitizer does not match mechanically, it is wider in X and smaller in Y.
So I just taped to the outside of my display.

I calibrated the thing and now I have working touch.


I am thinking about designing a minimal adapter board for the MN820.

Yes, the 15.6" really is some large unit of a monitor, I have no idea why that is still the only option.
I am generally interested in buying a RVT156HKBNWCA0-B, despite the price and despite that I have no idea what to actually do with it.

I do have a couple of issues with it though that I asked Riverdi about and I did not get an answer.

First of all the backlight, that cable that is sticking out to the side on the top.
Why? If I would order displays in any meaningfull quantity, I would tell the supplier to redesign that.
Riverdi did the same with the 12.1", which is one of the reasons I never bought one.

My second issue with the RVT156HKBNWCA0-B is the barrel connector to supply it.
Not only is a barrel connector not locking, that thing has a height of 11mm.
I would have preferred a 662102145021 from WE or a 505578-0271 from Molex.

So, yes, I would buy a 10" version, or even a 12.1" version if the backlight connection is fixed.
And I would opt for a way smaller external flash, like 64MBit, using the external SD card is nice.
Same with the DDR3 SRAM, 4GBit seems excessive.

What's up? 
It has been three weeks again since the last post while there are 75+ daily visistors listed.

I implemented all of the BT822 patch functions, or at least these that are documented so far.
Actually testing these still is difficult since the new EAB has not been released.

I would like to buy a BT82x based display module, but the options are still very limited.

Today I received a ACD-110DHTT which is a 10.1" industrial touch monitor that I got used for only 23€ from EBay, 1280x800.
And of course I only took it apart, really nice build quality, the case is machined from a block of aluminium, I do not want to know how much these cost before they were phased out back in 2019.
The panel is a G101EVN01.0 from AUO for which I even found a datasheet, LVDS, single channel, 6 bits per color.

The touch is a separate unit and will provide more challenges, it uses an eGalax Touch controller.
On the outside the interface is USB, but it does support I2C as well.


Now, what is everyone else here up to?

Edit: I really have no idea why this site is practically dead, 144 views of this post and no reaction?
Ok, stay positive. :-)


I just spent some time to check the wiring of the ACD-110DHTT and adapt it the VM820C.
As it turned out, the wire harness of the display is using the exact same 6 pin / 2mm header for the backlight than the VM820C, I only had to swap two pins. 
And for LVDS the wire harness connects to the conroller board with a 32 pin / 2mm header which uses the same crimps than the 30 pin / 2mm headers I have for the LVDS TX of the VM820C.
The pinout was slightly different, but taking out the pins from the old header and putting it in the 30pin header was really easy.

Next I put in a 1280x800 profile, checked the data format, which is JEIDA / Format 1 for 18-bit RGB, checked the clock frequency range and configured REG_LVDSTX_PLLCFG accordingly.
And, yeah, it worked on the first try. 
Even the backlight control is working, as the panel has the backlight controller integrated and takes a PWM signal to control it.

I do not have touch, did not even try to connect it, so far I have no idea if the eGalax touch controller is compatible to anything the BT820 supports.

I realized it has been a while since I updated this blog, hrmm, thread. :-)

I was discussing the LVDS input over on Github and to make that short, turned out that PCB800099 I bought is garbage, or at least the firmware on it for the RTD2660H is garbage.
The HDMI input is not working.
At least the OSD was working, but only for a few seconds and then it froze.

So I bought an inexpensive AV camera: "Car HD Reversing Camera" - mostly lies in the product description, as expected.
I tore it apart and found an analog camera module with 3.3V supply inside.
I soldered that to the AV2 input of the PCB800099 and since then I have continuous video input without freezes, sort of, the video is rather distorted and the PCB800099 reports "NTSC" for the input.

Whatever, the LVDS input to the BT820 is working fine now.

Fast forward, I am exploring the ability of the BT820 now to patch the firmware with both updated functions and additional functions.

I implemented CMD_LOADPATCH and copied a bunch of patchfiles to the SD card I am using with the VM820C.
EAB 4.1.x will have a new panel to supply these patches, but that is not yet released, so I converted patches from the BRT repositories to .bin.
And I just noticed that the "patchb2tf" that is shown in the screenshot is outdated, the patch_b2tf2.py this is taken from was updated a couple of days ago.
So I just updated my patch and to make a second screenshot more interesting, I also implemented CMD_SEVENSEG - only to find it not working properly which I will report next on Github.

Thanks for the update, I will keep an eye out for it then and play in the meantime with the few patches I found before in your repositories.

Hello,

I just found this:
https://brtchip.com/wp-content/uploads/2025/08/BRT_AN_095_BT82X-Firmware-Update-and-Extension-Guide.pdf

Nice, I was expecting something like this.

But the referenced patches are not available yet as an not yet released EVE Asset Builder is supposed to provide these in a new EXTENSION tab.
Please attach a full .bin here in the meantime for testing, the base patches and all extension patches in one binary.
Or, if that needs to be handled separately for some reason, the mentioned base_patch.bin plus a binary with all extension modules.

I would just drop that on the SD card for the BT820.

Thanks, so it was the "Display list instruction overfetch".
I even already had BRT_TN_005_BT81x_Errata_Technical_Note.pdf.

I just was not looking under https://brtchip.com/document/technical-notes/ , maybe add (Errata) to that one as well?

Oh, and another small thing, "Programming and User Guides" is sorted by date, newest on top, could that perhaps be done on "IC Data Sheets" and "Application Notes" as well?

I recently found this:
https://brtchip.com/wp-content/uploads/2024/04/Errata-notification-2024-R2.pdf

It states:
"We are reaching out to notify an important Errata that has been identified on our BT81x / BT88x series. This
Errata pertains to specific user applications, which may affect the functionality or performance of the product
under certain conditions."


What this does not state is what the actual issue might be.
So, what is it?

Given the date of release this could appear in a version of BT81X programming guide later than 2.4.
But I don't see anything in the 2.5, 2.6 or 2.7 history that indicates an issue.

I vaguely recall seeing extra DISPLAY commands added to the end of the command list to address some issue, is this related to this erratum?

The PCB800099 has arrived and five minutes later I realized that I am not prepared.
I need a cable with 2mm 30pin headers on both side.
And checking the pinout of CN2 on the VM820C and the LVDS pinout on the PCB800099, these are almost the same, except that polarity is different for all signals, so _P and _N swapped.

Unfortunately 30pin to 30pin LVDS cables apparently are rare, could not find any for speedy delivery, looks like I will be soldering tomorrow...

Edit: looking for information for the PCB800099 I came across a list on Alibaba.com for exactly the board I have with the exact same silkscreen and the "30P LVDS Interface connector: Pin definition:" contradicts the silkscreen - oh dear.

Ah, thanks, I have seen this document, but not the update.
I could not find boards with the RTD2513 in my last search I did, only from AliExpress, found two on EBay now as well which did not show before.
I bought a board with a RTD2660 which hopefully arrives by the end of july...
I was about the but one with the RTD2513 as well but it would be delivered in august, damn lazy bike couriers. 

And in regards of the video source, my issue is more with the budget I am willing to spend on this, when you have no application, a camera for 50+ bucks is kind of expensive. 

But looking at stuff like small video players, I just remembered that I have a RaspberryPi Zero somewhere in the office that I bought years ago and never used for anything.
And I just found that there is a RP2350-PiZero from Waveshare, only found it on AlixExpress though.

Edit: I just learned that the PCB800099 I ordered with the RTD2620 has an OSD and delivers a blue screen with a "No Signal" message, getting this to display by the BT820 would be a good start.   

That indicates that you did the touch calibration without rotation.
Either use CMD_SETROTATE which also adjusts the touch transform matrix, or calibrate the touch after setting REG_ROTATE.

Edit: damn, 35s too slow because I had to get up and turn off the washing mashine.