Need help connecting an arduino tft to a SKR Pro
February 17, 2021 08:07PM
I am trying to setup an SKR Pro V1.2 with this Arduino TFT (ILI9486)
[www.amazon.ca]

But I do not know how to connect it up and then how to configure it in Marlin.
I have tested the screen on an arduino nano with mcufriend_kbv and got display and touch working.


From my basic understanding, for touch, I need to connect the XP(LCD_D6), XM(LCD_RS), YP(LCD_WR), YM(LCD_D7) pins to ADC pins, I have found some available on the extension ports of the SKR Pro V1.2

As for the rest, im not too sure either.

This is the pin mapping for EXP1 and EXP2 ports of the SKR Pro V1.2

 *               -----                                             -----
 *           NC | 1 2 | GND                                    5V | 1 2 | GND
 *        RESET | 3 4 | PF12(SD_DETECT)             (LCD_D7)  PG7 | 3 4 | PG6  (LCD_D6)
 *   (MOSI)PB15 | 5 6   PF11(BTN_EN2)               (LCD_D5)  PG3 | 5 6   PG2  (LCD_D4)
 *  (SD_SS)PB12 | 7 8 | PG10(BTN_EN1)               (LCD_RS) PD10 | 7 8 | PD11 (LCD_EN)
 * (SD_SCK)PB13 | 9 10| PB14(MISO)                 (BTN_ENC)  PA8 | 9 10| PG4  (BEEPER)
 *               -----                                             -----
 *               EXP2                                              EXP1



any help would be appreciated,
thanks
Attachments:
open | download - IMG_20210216_175752_.jpg (920.5 KB)
Re: Need help connecting an arduino tft to a SKR Pro
February 17, 2021 08:24PM
That is not a currently supported TFT type

Marlin only knows how to talk to 'ST7735', 'ST7789', 'ST7796', 'R61505', 'ILI9328', 'ILI9341', 'ILI9488'

If your lucky it might be very close to a ILI9488, less colours for a start...

Datasheats
ILI9486 [www.waveshare.com]
ILI9488 [www.elecrow.com]

Edited 4 time(s). Last edit at 02/17/2021 09:47PM by Dust.
Re: Need help connecting an arduino tft to a SKR Pro
February 17, 2021 09:24PM
The touch looks like a standard resistivity 4 wire.

only needs 2 analogue pins and two digital pins have a look at [www.instructables.com]
Re: Need help connecting an arduino tft to a SKR Pro
February 18, 2021 01:30AM
I've been talking with a TFT expert (he wrote most if not all of the code in marlin for them)

This TFT is a FSMC device. The FSMC implementation in marlin expects FSMC devices to be on a dedicated FSMC IO pins. These IO pins are not on the exp ports.
This will not work on your controller at present.
In theory a bit banging implementation could be written (if sufficient IO pins are available), but it would be horribly slow (read as unusable slow!)

You need a SPI based TFT device on that controller, or a "smart' TFT screen that is just a serial device.
Re: Need help connecting an arduino tft to a SKR Pro
February 18, 2021 08:11PM
The SKR Pro has quite bit more unused pins as it uses the 144 pin STM32F4, some of EXP1/2 pins have fsmc capability and many of the extension-1 and extension-2 also have fsmc function.

I found all the pins in those headers that have fsmc functions in the stm32 spec. (see attached image)

Edited 6 time(s). Last edit at 02/20/2021 05:58PM by gaby_64.
Attachments:
open | download - IMG_20210218_212812_.jpg (796.7 KB)
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