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DT028ATFT-PTS documentation and CAD libraries

Hi,
I have studied the EMB028TFTDEMO-PTS_RevX4and6 project and I would like some details.
- 1) Can you confirm that the XD (pin42), XR (pin 43), XU (pin 44) and XL (pin45) are not useful for DT028ATFT-PTS ?
- 2) The schematic of EMB028TFTDEMO-PTS_RevX4and6 uses a external RAM memory. I don't understand all the code associated, but I think that the application "calculator" need it. Can you confirm that with only SPI communication the DT028ATFT-PTS works to display graph and text ? I have a doubt because IM[3..0] signal (pin 6..9) is fixed for SPI communication but the VSYNC, HSYNC, DB[15...0] are routed to Microchip (probably not used). In others words, can you confirm that the DT028ATFT-PTS can be used with only 2 bus communication : SPI to display graph and text, and I2C to know the XY position on touch screen ? (no need data bus DB[16..0]
- 3) I would like to recover the Altium librairie used for EMB028TFTDEMO-PTS_RevX4and6 (to have symbols and footprints). Please can you send me or give me contact to someone who I can ask ?

Best regards

Replies

engineering_seacomp's picture
engineering_seacomp
September 18, 2019

1) Correct.  This is for resistive touch.  PCAP usese the seperate connector.

2) In general, you could configure the EM028TFTDEMO-PTS to work either way (based on the IM pins).  However the display will work with:

* RGB for graphics and text (with control through SPI only) (see ILI9341_SPI.c) 

* MCU Mode: Parallel Bus (Called PMP in EM028TFTDEMO-PTS), or SPI, with graphics and text.

The ILI9341 datasheet is difficult to understand.  If the table for IM pins don't say "MCU", then it is implied RGB.

The configuration for EMB028TFTDEMO-PTS is IM3-0=0101 which is 3 wire-9bit for control interface, and uses DB0-DB17 for RGB Data.  The micro-controller uses DMA (using the external RAM) as display buffer.

The PCAP (touch) interface is I2C using CN2

I'm sorry, we can't provide the altium library.

Eric's picture
Eric
September 19, 2019

Hi,

Thank you very much for your response.

1/ Ok. With DT028ATFT-PTS, XD (pin42), XR (pin 43), XU (pin 44) and XL (pin45) are not used. But what is the pin schematic : NC (not connected), VSS or VDD ? I think NC, can you confirm.

2/ Sorry, I don't understand the RGB and/or MCU mode. In my application, I want display text (for example date/time/name) and graphic (for example a bitmap). Is is possible with only SPI communication (no utilisation of DB0-DB17 pin) ?

3/ I understand and I don't understand. I would like the symbol and footprint to create my own project as soon as possible without mistake. No to clone your demo board. Please can you reconsider your initila answer.

Best regards

engineering_seacomp's picture
engineering_seacomp
September 20, 2019

Hi,

Hopefully this provides clarity.

1) NC

2) Yes.  In MCU mode you can display graphics by writing directly to GRAM in the ILI9341 (the driver IC on the display glass called COG).

The ILI9341 supports smart glass (MCU mode) and dumb glass (RGB mode).

See this presentation to learn:

https://www.dropbox.com/s/ncg4za178tlx2nn/19038_GFX1_FinalSlides.pdf?dl=0

3) I'm sorry, our company policy (similiar to many) is to only provide the schematic, not the layout or library files.

Thanks

 

 

Eric's picture
Eric
September 21, 2019

Hi,

Thank for your patience.

1/ ok

2/ Not clear for me. Sorry. The presentation is nice but very focused on Microchip design. Unless I'm wrong, the SPI communication is mentioned only slide 65 to introduce a TCON. So, I read the ILI9341_SPI.c file and the code uses the controller SSD1926 or S1D13517. But when I buy a DT028ATFT-PTS, I don't know what controller chip is inside, doesn't it ?

Please, lets me describe my project : On DT028ATFT-PTS screen, I want to display :

   - picture (as .bmp),

   - shape (as circle/rectangle/...) and

   - text (as current time, )

The DT028ATFT-PTS is interfaced to an ESP32 micro-controller via

  - SPI to write data to display picture/shape/text and

  - I2C to retrieve the coordinates of point touch.

Questions:

2.1/ Is it possible as describe above ?

2.2/ What is the configuration for EMB028TFTDEMO-PTS Interface mode: IM[3..0]=0101, IM[3..0]=0110, IM[3..0]=1101 or IM[3..0]=1110 because I don't understand SDA vs SDI/SDO use ? In my application, I think IM[3..0]=1110

2.3/ For my application, is it correct to :

    - unconnect signal FMARK/VSYNC/HSYNC/DOTCLK/DB[17..0]

    - connect VSS to signal ENABLE/WR/RSSCL/RD

3/ I understand your company policy but I'm not a rival but a futur customer of your product. I design a new board with your touch screen and I want to have the maximum chance of succeeding in my design. I find it unpleasant to rebuild a library on a component I want to buy. A mistake happens very quickly (for example, in your EMB028TFTDEMO-PTS...revX6 8/4/2016, 1:57:15PM, the signal DB0 is missing - pin32 is renamed by mistake DB5). I need only the altium schematic/pcb library of U6, J2 and CN2 components.

Best regards

engineering_seacomp's picture
engineering_seacomp
September 24, 2019

2.1) Yes.  You will use a grapics library (not provided by displaytech) to write data to be displayed on the screen using SPI using MCU mode.  You write to GRAM in the ILI9341 and it shows up on the display (assuming you properly iniatlize).

2.2) The answer was previously provided.  The configuration for EMB028TFTDEMO-PTS is IM3-0=0101 which is 3 wire-9bit for control interface, and uses DB0-DB17 for RGB Data.  The micro-controller uses DMA (using the external RAM) as display buffer.

To do what you want "the DT028ATFT-PTS is interfaced to an ESP32 micro-controller via"

  - SPI to write data to display picture/shape/text and

Have you looked in our "Design Center" for "DT028ATFT Resource" "Display to MCU Connections"?

https://cdn.displaytech-us.com/sites/default/files/resources/DT028ATFT-Display-to-MCU-Connections.pdf

You need to set IM pins to IM3-0=0110 to use "8-bit Serial 1 (SDA+D/CX)" in MCU mode.  Use pin 39 for SDA, pin 34 for D/CX, 33 for CS, and pin 35 for SCL.

or

You need to set IM pins to IM3-0=1110 to use "8-bit Serial II (SDA+SDO+D/CX)" in MCU mode. Use pin 39 for SDA, pin 34 for D/CX, 33 for CS, and pin 35 for SCL and pin 38 for SDO.

Please see ILI9341 datasheet for Section 7 for the corresponding signals.

https://cdn.displaytech-us.com/sites/default/files/driver-ic-data-sheet/Ilitek-ILI9341.pdf

3) This IS NOT A MISTAKE.  This ties the colors to 5-6-5, setup for 16 bit color.

 

Eric's picture
Eric
September 28, 2019

Hi,

Thanks for all your responses.

Best regards