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.

These are OPEN-SMART TFT-Shield Products.

Software requirements

esp-idf v4.4/v5.x.

Note for ESP-IDF V5.x
ESP-IDF V5.x gives this warning, but work.

#warning "legacy adc driver is deprecated, please migrate to use esp_adc/adc_oneshot.h and esp_adc/adc_continuous.h for oneshot mode and continuous mode drivers respectively"

Installation

git clone https://github.com/nopnop2002/esp-idf-parallel-tft
cd esp-idf-parallel-tft/
idf.py set-target {esp32/esp32s2/esp32s3}
idf.py menuconfig
idf.py flash

Note for ESP32-S2
The tjpgd library is not present in ESP32-S2 ROM.
With ESP-IDF Ver5, the JPEG decode library is now provided from the IDF Component Registry, and the JPEG decode library is now available for ESP32-S2.
However, since the ROM is small, a large image cannot be displayed.
With ESP-IDF Ver4.4, you cannot be displayed JPEG files because the IDF Component Registry cannot be used.
PNG file cannot be displayed because the SRAM is small.

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)
  I2S parallel is suitable for image-intensive applications.
  REGISTER I/O parallel is suitable for character-intensive applications.
  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

TFT		ESP32	ESP32S2/S3
LDC_RST	--	GPIO32	GPIO45	*1
LDC_CS	--	GPIO33	GPIO42	*1
LDC_RS	--	GPIO15	GPIO41	*1
LDC_WR	--	GPIO4	GPIO40	*1
LDC_RD	--	GPIO2	GPIO39	*1
LDC_D0	--	GPIO12	GPIO1	*1 *2
LDC_D1	--	GPIO13	GPIO2	*1 *2
LDC_D2	--	GPIO26	GPIO3	*1 *2
LDC_D3	--	GPIO25	GPIO4	*1 *2
LDC_D4	--	GPIO17	GPIO5	*1 *2
LDC_D5	--	GPIO16	GPIO6	*1 *2
LDC_D6	--	GPIO27	GPIO7	*1 *2
LDC_D7	--	GPIO14	GPIO8	*1 *2
5V	--	5V	5V	*3
3.3V	--	3.3V	3.3V	*3
GND	--	GND	GND

(*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.
You can specify multiple fonts at the same time.

Image support

BMP file
JPEG file
PNG file

Using Wemos D1 ESP32

I bought this for $4.

To attach the TFT-Shield, you need to do changed some pin assignments like this.
Because GPIO34/35/36/39 are READ ONLY.

With this change, GPIO will look like this:

It's great because it doesn't require any wiring.

If you use OPEN-SMART TFT-Shield Products, you must use custom GPIO.

Using TZT D1 ESP32-S3

I bought this for $5.

You can attach the TFT-Shield without changing anything.
But I2S parallel doesn't work. I don't know why.

If you use TZT D1 ESP32-S3, you must use 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 are connected with two wires.
(Y+) and ESP32 are connected with 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)

Configuration for touch screen

• 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/S3 has 10 channels: GPIO01 - GPIO10.
  Refer to the ESP32 data sheet for the relationship between ADC channels and GPIOs.
  When using ADC1_6(ADC1 Channel#6) and ADC1_7(ADC1 Channel#7), the following wiring is additionally required.

TFT	ADC1	ESP32	ESP32S2/S3
LCD-WR(Y+)	Channel#6	GPIO34	GPIO07
LCD-RS(X-)	Channel#7	GPIO35	GPIO08

• GPIO number
  It uses four GPIOs, but the GPIOs differ depending on the TFT model.

• Save calibration data to NVS
  Write calibration data to NVS.
  Read calibration data from NVS when starting the firmware and use it.
  If you use the same TFT, you don't need to calibrate again.
  To clear the calibration data recorded in NVS, execute the following command.

idf.py erase_flash

OPEN-SMART 16Pin-Parallel Products

X(+)	X(-)	Y(+)	Y(-)
LCD_D6	LCD_RS	LCD_WR	LCD_D7

OPEN-SMART TFT-Shield Products

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

X(+)	X(-)	Y(+)	Y(-)
LCD_D6	LCD_RS	LCD_WR	LCD_D7

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

TFT		ESP32	ESP32S2
LCD_WR(Y+)		ADC1_6(GPIO34)	ADC1_6(GPIO07)
LCD_RS(X-)		ADC1_7(GPIO35)	ADC1_7(GPIO08)

4-line resistance touch screen cannot be used with the Wemos D1 ESP32.
Because the combination of GPIO and ADC does not match.

ELEGOO TFT-Shield Products

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

X(+)	X(-)	Y(+)	Y(-)
LCD_D0	LCD_RS	LCD_CS	LCD_D1

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

TFT		ESP32	ESP32S2
LCD_CS(Y+)		ADC1_6(GPIO34)	ADC1_6(GPIO07)
LCD_RS(X-)		ADC1_7(GPIO35)	ADC1_7(GPIO08)

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.

X(+)	X(-)	Y(+)	Y(-)
LCD_D0	LCD_RS	LCD_CS	LCD_D1

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

TFT		ESP32	ESP32S2
LCD_CS(Y+)		ADC1_6(GPIO34)	ADC1_6(GPIO07)
LCD_RS(X-)		ADC1_7(GPIO35)	ADC1_7(GPIO08)

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.

X(+)	X(-)	Y(+)	Y(-)
LCD_D6	LCD_RS	LCD_WR	LCD_D7

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

TFT		ESP32	ESP32S2
LCD_WR(Y+)		ADC1_6(GPIO34)	ADC1_6(GPIO07)
LCD_RS(X-)		ADC1_7(GPIO35)	ADC1_7(GPIO08)

4-line resistance touch screen cannot be used with the Wemos D1 ESP32.
Because the combination of GPIO and ADC does not match.

Other TFT

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

Calibrating the touch screen

Keep touching the corner point.

Draw with touch

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

Button with touch

You can only enter up to 15 characters.
If there is no touch for 10 seconds, it will end.

Move with touch

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

Menu with Touch

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

Select image with touch

If there is no touch for 10 seconds, it will end.
I borrowed the icon from here.

How dose it works

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

Application layer

Performance comparison using ILI9488(320x480)

I2S parallel is not always faster.
Compiling with the O2 option doesn't help much.

Test	GPIO parallel	REGISTER I/O parallel	I2S parallel	I2S parallel(O2)
AddressTest	820	280	40	30
FillTest	3900	2370	1620	1590
ColorBarTest	810	290	60	40
ArrowTest	860	300	160	140
LineTest	2060	860	3150	2900
CircleTest	1950	830	2840	2610
RoundRectTest	1970	820	2930	2690
RectAngleTest	2810	1340	5180	4880
TriangleTest	2960	1530	6090	5640
DirectionTest	900	330	250	230
HorizontalTest	1110	430	610	550
VerticalTest	1110	430	610	550
FillRectTest	1300	590	200	140
ColorTest	1660	650	220	180
BMPTest	7280	6500	6130	5790
JPEGTest	1210	490	170	140
PNGTest	1480	750	440	1010

Performance comparison using ILI9341(240x320)

SPI used this.

Test	SPI	GPIO parallel	REGISTER I/O parallel	I2S parallel
FillTest	1620	2700	1920	1560
ColorBarTest	80	410	150	30
ArrowTest	250	450	160	140
LineTest	2770	1030	430	1570
CircleTest	2470	970	410	1410
RoundRectTest	2510	970	400	1430
RectAngleTest	5990	2000	940	4050
TriangleTest	6950	2110	990	4740
DirectionTest	420	500	190	240
HorizontalTest	1030	710	290	590
VerticalTest	1010	710	290	590
FillRectTest	170	710	340	120
ColorTest	250	850	340	150
BMPTest	7470	6880	6360	6120
JPEGTest	2530	800	350	150
PNGTest	2800	1070	610	420

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
• for esp32s3
  8080_lcd_esp32s3.c
• Common header
  i2s_lcd_driver.h