TFT 3.2" in 8 bit interface mode

Discussion in 'Embedded Systems and Microcontrollers' started by sairfan1, Aug 8, 2014.

  1. sairfan1

    Thread Starter Member

    May 24, 2012
    46
    1
    Hi,

    I have some TFT 3.2" (driver SSD1289, HX8352 and ILI9481) as these all have 16bit interface. after spending hours still i could not find out how can i interface it in 8 bit mode, in datasheet i read that it can be connected in 8 bit mode and even in serial mode, but did not find any instruction or command. Please help if any one have tried it. thanks
     
  2. shteii01

    AAC Fanatic!

    Feb 19, 2010
    3,374
    494
    Datasheest?
    Where?
    Links?
     
  3. shteii01

    AAC Fanatic!

    Feb 19, 2010
    3,374
    494
    Generally, first you setup the TFT to work in 8 bit mode, second you divide your data into 8 bit chunks, you send the high 8 bits first then you send low 8 bits. That's about it.

    Do you have TFT command and instruction set/list/table?
     
  4. NorthGuy

    Active Member

    Jun 28, 2014
    602
    120
    Often there's a pin which controls whether it uses 8-bit or 16-bit mode.
     
  5. sairfan1

    Thread Starter Member

    May 24, 2012
    46
    1
    sorry for late reply, i dont know why i did not receive notification of reply posted.

    Anyway i have attached datasheets, these are general China based TFTs 320x240, i noticed basic config is common, i have successfully run in 16bit mode. but no further ports left on my mcu, must need to run in 8 bit mode.
     
  6. NorthGuy

    Active Member

    Jun 28, 2014
    602
    120
    Look at the very beginning of table 4.1 on page 12. It explains how to set P68,BS0,BS1, and BS2 pins to select a mode.
     
  7. sairfan1

    Thread Starter Member

    May 24, 2012
    46
    1
    i understand, these are pins of TFT driver, not interface pins, i need to set this value through some command. at page 16 of SSD1289 there are some instructions, but i could not get the point.
     
    Last edited: Aug 9, 2014
  8. shteii01

    AAC Fanatic!

    Feb 19, 2010
    3,374
    494
    Try page 69.
     
  9. NorthGuy

    Active Member

    Jun 28, 2014
    602
    120
    Page 19. PS0-PS3 pins.

    Also Page 21. The very beginning of section 7.1.
     
  10. sairfan1

    Thread Starter Member

    May 24, 2012
    46
    1
    Thanks for reply, im working on SSD1298 for now, can you please advise when using in SPI (3pin) mode which of the data pins are used for SPI mode like CLK, SDI, SDO?
     
  11. NorthGuy

    Active Member

    Jun 28, 2014
    602
    120
    All of these three.
     
  12. sairfan1

    Thread Starter Member

    May 24, 2012
    46
    1
    yes but these are not on TFT interface, looks like some of data pins D0 to D15 are used for serial communication alternatively, i uploaded image for pin reference

    [​IMG]
     
    Last edited: Aug 12, 2014
  13. sairfan1

    Thread Starter Member

    May 24, 2012
    46
    1
    Hi,

    while discussing with some friends i came to know that most of Chinese suppliers do not provide correct datasheet of product, you have to do effort at your own, i was advised to pull out TFT from its PCB mount, there i found exact driver number which is SSD1289, furthermore most of vendors do not provide configuration pins on PCB, so you have to pullout TFT and find where configuration pins are, if you are expert you may change its configurations, it may damage your TFT so should be done very carefully.

    Incase i change configuration still it is not clear that which pins act like SPI pins in serial mode. because there are no pins marked with SPI interface.
     
  14. shteii01

    AAC Fanatic!

    Feb 19, 2010
    3,374
    494
    Vote with your wallet. If they don't provide accurate information, don't buy their products.
     
  15. NorthGuy

    Active Member

    Jun 28, 2014
    602
    120

    How about SD_CS, SD_DIN, SD_CLK, SD_DO pins on the upper right corner?
     
  16. shteii01

    AAC Fanatic!

    Feb 19, 2010
    3,374
    494
    Those would be my choices too.
     
  17. THE_RB

    AAC Fanatic!

    Feb 11, 2008
    5,435
    1,305
    No, they are the SPI pins for the SD card which is also on the PCB.

    And the pins marked T_xx are SPI for the touchpanel controller.

    The display pins are on the left side, REST, CS, RD, WR, RS etc.

    It's a standard China ebay TFT pinout and there are plenty of wiring diagrams and code examples to google.
     
  18. sairfan1

    Thread Starter Member

    May 24, 2012
    46
    1
    there is also SPI interface for SD Card and Touch Panel, SD_CLK ... are pins for SD Card, T_CLK pins are Touch Panel interface. While reading different datasheets i understand some of data pins (D0 to D15) act as SPI interface in serial mode.
     
  19. shteii01

    AAC Fanatic!

    Feb 19, 2010
    3,374
    494
    Ah, that explains SD in front.
     
  20. NorthGuy

    Active Member

    Jun 28, 2014
    602
    120
    Do they have an SD-card slot on board? Or is it to interface the display directly to an external SD-card?

    It would be nice if you could post a picture of the entire board.
     
Loading...