How to setup and use TTL Type TFT-LCD on SP7021 EV Board

Owned by hammer.hsieh
Last updated: Jul 08, 2021
4 min read

SP7021 TTL Type TFT-LCD Support List

SP7021 EV board + adapter board + (TFT LCD panel with TTL interface)

such as

Winstar WF35LTIACDNNZ 3.5” 320x240

ALIENTEK ATK-7016 TFTLCD 7” 800x480

    SHENZHEN WEIYAO 10.1” WY101ML322HS18B 1024x600

Hardware Connect between SP7021 and TFT-LCD panel

1) Main Board :

SP7021 only support TTL RGB 24-bits module directly.

Currently , only SP7021 EV board can support TTL type TFT-LCD.

2) TFT-LCD panel:

Case1 :TFT-LCD panel with backlight power circuit and LCM bias power circuit.

    Case2 :TFT-LCD panel only.

3) Adapter Board (Main Board connect to TFT LCD):

Case1 :TFT-LCD panel with backlight power circuit and LCM bias power circuit.

          Adapter board just do TTL-to-TTL pin re-arrange.

For example :

ALIENTEK ATK-7016 TFTLCD 7” 800x480

    For connecting to TFT-LCD panel , it needs a lot of pin to control it.

DATA pin (24pins) : R[0]~R[7], G[0]~G[7], B[0]~B[7]

CONTROL Pin (4pins) : Hsync, Vsync, DE, CLK

SP7021 TTL pinout define (50pin)

ALIENTEK 7” connector pinout define (40pin)

Make SP7021 TTL to TFTLCD panel adapter board.

Case2 :TFT-LCD panel only.

          Adapter board needs more hardware work.

Adapter board reference design(See attached pdf file for your reference)

  • 5V to 3.3V power circuit (it depends on TFT-LCD panel maker)

  •           TFT-LCD panel backlight power circuit (it depends on TFT-LCD panel maker)

  •           TFT-LCD panel LCM bias power circuit (it depends on TFT-LCD panel maker)

For example :

Winstar WF35LTIACDNNZ 3.5” 320x240 adapter board

        SHENZHEN WEIYAO 10.1” WY101ML322HS18B 1024x600 adapter board

Software Configuration for TFT-LCD panel

Due to TFT-LCD function use a lot of pins , most SP7021 based PCB design choose not to support it. If you choose to use TFT-LCD , many default function must disable or shift some default function pinout to other place.

Kernel Display driver dts setting

   Copy ./linux/kernel/arch/arm/boot/dts/sp7021-ev-ttl.dts all content

   to   ./linux/kernel/arch/arm/boot/dts/sp7021-ev.dts

1) Winstar WF35LTIACDNNZ 3.5” 320x240

#define ENABLE_TTL_320X240

2) ALIENTEK ATK-7016 TFTLCD 7” 800x480

#define ENABLE_TTL_800X480

3) SHENZHEN WEIYAO 10.1” WY101ML322HS18B 1024x600

#define ENABLE_TTL_1024X600

System Application on linux OS

1) Winstar WF35LTIACDNNZ 3.5” 320x240

2) ALIENTEK ATK-7016 TFTLCD 7” 800x480

 

3) SHENZHEN WEIYAO 10.1” WY101ML322HS18B 1024x600