esp-idf-parallel-tft

8 bit parallel TFT & 4-line resistance touch screen Driver for esp-idf.
You can use such a TFT-Shield with esp32.

Support driver

Generic Shield

• ILI9225
• ILI9226(Same as ILI9225)
• ILI9320
• ILI9325
• ILI9341
• ILI9342
• ILI9481
• ILI9486
• ILI9488
• SPFD5408(Same as ILI9320)
• R61505U(Same as ILI9320)
• R61509V
• LGDP4532
• ST7775(Same as ILI9225)
• ST7781
• ST7783(Same as ST7781)
• ST7793(Same as R61509)
• ST7796(Same as ILI9486)
• HX8347A(*2)
• HX8347D(Almost the same as HX8347A)(*2)
• HX8347G(Same as HX8347D)(*2)
• HX8347I(Same as HX8347D)(*2)

OPEN-SMART Products

• OPEN-SMART ILI9225 TFT-Shield(176x220)(*5)
• OPEN-SMART ILI9327 TFT-Shield(240x400)(*3)(*5)
• OPEN-SMART ILI9340 TFT-Shield(240x320)(*5)
• OPEN-SMART S6D1121 16Pin-Parallel(240x320)(*1)(*5)
• OPEN-SMART ST7775 16Pin-Parallel(176x220 Same as ILI9225)(*1)(*5)
• OPEN-SMART ST7783 16Pin-Parallel(240x320)(*1)(*5)
• OPEN-SMART R61509V 16Pin-Parallel(240x400)(*1)(*5)
• OPEN-SMART ILI9488 16Pin-Parallel(320x400 Color inversion)(*1)(*4)(*5)

(*1)
I2S parallel does not work.
I don't know why.
GPIO parallel or REGISTER I/O parallel works.
LED pins connect to GND instead of 3.3V.

(*2)
Very Slow.
Most drivers require three commands to display one Pixel.
This driver require 9 commands to display one Pixel.
For some reason, the color of 0xFFFF does not appear.

(*3)
It has a GRAM offset.
See below.

(*4)
Need RGB inverstion.

(*5)
4-line resistance touch screen available.
See below.

These are all 2.4 inch, 320x240 TFTs.

3.95 inches is almost twice as large as 2.4 inches.

These are OPEN-SMART 16Pin-Parallel Products.

Software requirements

esp-idf v4.4 or later.
The i2s driver for esp32s2 is supported.

Installation for ESP32

git clone https://github.com/nopnop2002/esp-idf-parallel-tft
cd esp-idf-parallel-tft/
idf.py set-target esp32
idf.py menuconfig
idf.py flash

Installation for ESP32-S2

git clone https://github.com/nopnop2002/esp-idf-parallel-tft
cd esp-idf-parallel-tft/
idf.py set-target esp32s2
idf.py menuconfig
idf.py flash

Note

• tjpgd library does not exist in ESP32-S2 ROM. Therefore, the JPEG file cannot be displayed.
• PNG file cannot be displayed because the SRAM is small.

Installation for ESP32-S3

i2s_lcd_esp32s3_driver.c does not exist yet in here.

Configuration

You have to set this config value with menuconfig.

• CONFIG_DRIVER
  
  The information provided by sellers on Ebay or AliExpress is largely incorrect.
  You waste time if you don't choose the right driver.
  There are many variations of the 2.4 inch shield.
  You can use this to find out your driver.
  This is for Arduino UNO.
  Do not use this on the ESP32 as the GPIO on the ESP32 is not 5V tolerant.
  Never believe the seller's information.
  I'll say it again.
  Never believe the seller's information.
• CONFIG_INTERFACE
  Most drivers work using I2S parallel.
  However, some drivers only work using GPIO parallels or REGISTER I/O parallels.
  I2S parallel is the fastest when drawing to consecutive addresses.
  However, REGISTER I/O parallel is the fastest when drawing to non-contiguous addresses.
  When using REGISTER I/O parallel, GPIO from D0 to D7 is 1 to 31.(GPIO0 is boot mode pin)
  GPIO parallel is most slow.
• CONFIG_WIDTH
• CONFIG_HEIGHT
  Specifies the resolution of the TFT.
• CONFIG_OFFSETX
• CONFIG_OFFSETY
  You can specify the GRAM offset.
  You must specify Y offset = 32 for OPEN-SMART-ILI9327.
• CONFIG_INVERSION
  For some TFTs, the BGR may be inverted.
  Specify if the colors are inverted.

Wireing

(*1)
You can change any GPIO using menuconfig.

(*2)
When using REGISTER I/O parallel, GPIO from D0 to D7 is 1 to 31.(GPIO0 is boot mode pin)

(*3)
With a regulator (mostly AMS1117) is on the back, the supply voltage is 5V.
With a regulator is NOT on the back, the supply voltage is 3.3V.

Note
My R61509V has a regulator on the back.
Normally, a TFT with a regulator works at 5V, but my R61509V doesn't work unless I supply both 5V and 3.3V.

Note
ESP32 development board cannot supply too much current.
It is more stable when supplied from an external power source.

Graphic support

Fonts support

It's possible to text rotation and invert.
It's possible to indicate more than one font at the same time.

Image support

BMP file
JPEG file(ESP32 only)
PNG file(ESP32 only)

Using Wemos D1 ESP32

I bought this for $4.

I have changed some pin assignments.
Attached the TFT shield.
The TFT shield worked fine.

It's very smart.

If you use OPEN-SMART TFT-Shield Products, you have to change Custom GPIO.

JPEG Decoder

The ESP-IDF component includes Tiny JPEG Decompressor.
The document of Tiny JPEG Decompressor is here.
This can reduce the image to 1/2 1/4 1/8.

PNG Decoder

The ESP-IDF component includes part of the miniz library, such as mz_crc32.
But it doesn't support all of the miniz.
The document of miniz library is here.

And I ported the pngle library from here.
This can reduce the image to any size.

Font File

You can add your original font file.
The format of the font file is the FONTX format.
Your font file is put in font directory.
Your font file is uploaded to SPIFFS partition using meke flash.

Please refer this page about FONTX format.

FontxFile yourFont[2];
InitFontx(yourFont,"/spiffs/your_font_file_name","");
uint8_t ascii[10];
strcpy((char *)ascii, "MyFont");
lcdDrawString(dev, yourFont, x, y, ascii, color);

4-line resistance touch screen

Some TFT has 4-line resistance touch screen.
The 4-line resistor touch screen uses 4 pins.

• X(+):Digital Output
• X(-):Digital Output/Analog Input
• Y(+):Digital Output/Analog Input
• Y(-):Digital Output

When using GPIO Parallel Interface or REGISTER Parallel Interface, you can enable 4-line resistance touch screen using menuconfig.

ESP-IDF cannot simultaneous both digital output and analog input using a single gpio.
Two GPIOs are required for simultaneous digital output and analog input.
(X-) and ESP32 connecte by two wires.
(Y+) and ESP32 connecte by two wires.

(X-) ----+---- Gpio for Digital Output(Using GPIO number)
         +---- Gpio for Analog Input(Using ADC1 Channel number)

(Y+) ----+---- Gpio for Digital Output(Using GPIO number)
         +---- Gpio for Analog Input(Using ADC1 Channel number)

OPEN-SMART 16Pin-Parallel Products

• ADC Channel
  When reading analog values, ESP-IDF can use ADC1 and ADC2.
  This project use ADC1 to read analog value.
  ESP32 has 8 channels: GPIO32 - GPIO39.
  ESP32S2 has 10 channels: GPIO01 - GPIO10.
  Refer to the ESP32 data sheet for the relationship between ADC channels and GPIOs.

• Touch position accuacy
  The coordinates read from Y(+) and X(-) are analog values.
  The difference between the coordinates read last time and the coordinates read this time is determined, and if it is within this range, it is regarded as a valid coordinate.
  Decreasing this value will make the position more accurate, but less responsive.
  Increasing this value will make the position more inaccurate but more responsive.

When using ADC1_6(ADC1 Channel#6) and ADC1_7(ADC1 Channel#7), the following wiring is additionally required.

OPEN-SMART TFT-Shield Products

There is no marking about 4-line resistance touch screen.
But 4-line resistance touch screen available.

When using ADC1_6(ADC1 Channel#6) and ADC1_7(ADC1 Channel#7), the following wiring is additionally required.

4-line resistance touch screen cannot be used with the Wemos D1 ESP32.
Because LCD_WR (GPIO4) is ADC2_0.

ELEGOO TFT-Shield Products

There is no marking about 4-line resistance touch screen.
But 4-line resistance touch screen available.

When using ADC1_6(ADC1 Channel#6) and ADC1_7(ADC1 Channel#7), the following wiring is additionally required.

No additional wiring is required when using the Wemos D1 ESP32.
LCD_CS is assigned to ADC1_6 and LCD_RS is assigned to ADC1_7.

ILI9341 2.4inch TFT-Shield with Yellow Pin-header

There is no marking about 4-line resistance touch screen.
But 4-line resistance touch screen available.

When using ADC1_6(ADC1 Channel#6) and ADC1_7(ADC1 Channel#7), the following wiring is additionally required.

No additional wiring is required when using the Wemos D1 ESP32.
LCD_CS is assigned to ADC1_6 and LCD_RS is assigned to ADC1_7.

ILI9486 3.5inch TFT-Shield

There is no marking about 4-line resistance touch screen.
But 4-line resistance touch screen available.

When using ADC1_6(ADC1 Channel#6) and ADC1_7(ADC1 Channel#7), the following wiring is additionally required.

Other TFT

I don't know which pin is X(+), X(-), Y(+), Y(-).
If you find, please tell me.

Calibration

Keep touching the point.

Draw with touch

If there is no touch for 10 seconds, it will end.

How dose it works

https://www.sparkfun.com/datasheets/LCD/HOW%20DOES%20IT%20WORK.pdf

Application layer

Performance comparison using ILI9488(320x480)

Performance comparison using ILI9341(240x320)

SPI used this.

Reference about I2S driver

https://github.com/espressif/esp-iot-solution/tree/master/components/bus

• for esp32
  i2s_lcd_esp32_driver.c
• for esp32s2
  i2s_lcd_esp32s2_driver.c
• Common header
  i2s_lcd_driver.h