3

It is possible to connect this LCD TFT screen to the raspberry 3 model B please ? I don't understand the schematic for SPI connection. Any help is welcome thank you.

I have follow this answer but it does not help me.

Probably this library can help me for the driver, but I do not know how to connect that.

-products

-vma412_diagram

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UPDATE PROGRESS: enter image description here vma412_diagram / datasheets - ILI9341

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enter image description here data-sheet 74LVC_LVCH245A enter image description here

PCB screen side enter image description here

  • the SPI could be used only for the SD card .... what does the user manual say? – jsotola May 13 at 22:00
  • @jsotola, Thank you for your answers. Sorry for the "anymore" word , I'm not really English and I meant: "did not help me more than that". For SPI I have read SPI can be use for preserve GPIO pin . For SPI I read that SPI can be used to preserve GPIO pins. But I start so I can also misinterpret. In the user manual I have not found any specification about SPI, except in the diagram. – Ephemeral May 14 at 7:30
  • @jsotola, Finally, the features of SPI are in manual mode: serial interface 3 lines / 4 lines, but only for SD cards? good question. – Ephemeral May 14 at 7:35
  • Many thanks for the very detailed signal routing chart. I am glad to have found one more missing jigsaw piece - the relation between the signals "DC" and "SCL". I never have guessed that these two logical signals share the same physical line! – tlfong01 May 16 at 4:57
  • @tlfong01, You're welcome, for my part I can not understand why there is D/CX (SCL) but also WRX (D / CX), I suspect what is noted parenthetically to be the definitions for the serial line but for the moment I'm not sure. For SDO and SDA, I can not find the relationship on the pinout of my LCD. NC / SPI_SDA ... where is this pin on my LCD screen :) If I follow your CON1 and your last schema (Update 2019may15hkt1519) this seems to be SD_DO for SPI_SDO and SD_DI for SPI_SDA but I'm not sure for the moment. – Ephemeral May 16 at 7:41
5

Question

ILI9341 SPI 2.8" Touch TFT LCD Arduino Shield

Rpi3B+ OK? How to connect?

Short Answer

(S1)

Yes, it is OK to use the ILI9341 Arduino Shield for Rpi. The following is the wiring for using SPI mode interface.

ILI9341 Touch LCD Arduino/STM32 Shield to Rpi3B+ GPIO Wiring V0.1

ici9341 wiring

The following GitHub driver by juj has a comprehensive tutorial with detail description on the following:

  1. Introduction to the touch LCD driver.

  2. How to build the kernel module.

ILI9341 Touch LCD SPI Based Driver for Rpi3B+ stretch - juj 2019apr19

Some research notes and more references can be found in the long answer below.

Long Answer

Contents

Research Notes ...

Figures ...

References ...

Appendices ...

Research Notes

(L1)

First thing first - check out spec and schematic.

touch screen 01

touch screen 2

The OP's question is clear, and his reference web links are very good. So I followed his links and jot down a picture of the wiring.

touch screen wiring

The drive/library referred by the OP is a couple of years old, and no longer supported. So I need to google to catch up.

(L2)

so I googled and found everybody is using the ILI19341 de facto standard. That means all ILI19341 are more or less the same and can be used with any such driver. I searched AliExpress and found the following typical goody.

ILI19341 touch screen

I google to catch up and the the found the following tutorial looking good.

ILI9341 Raspberry Pi guide - pi0cket 2019feb26

It gives a clear wiring (see Reference below), and the detailed instructions and commands to switch between HDMI mon and TFT screen.

One thing I am not that happy is the following:

You cannot use HDMI monitor and TFT touch screen at the same time!

Figures

Fig 1 Fig 1 - Touch LCD

Fig 2 Fig 2 - 2.8" touch screen pinout

Fig 3 Fig 3 - STM32 LCD Module 32 pin socket

Fig 4 Fig 4 - Rpi spi pinout

Fig 5 Fig 5 - Touch lcd wiring

Fig 6 Fig 6 - Touch screen module

Fig 7 - Con 1 - 9 pin x 2 = 18 pin Connector

Con 1 - 9 pin x 2 = 18 pin connector

Fig 8 - vm412 Touch LCD signals

velleman lcd 01

Fig 9 - stm32 Touch LCD signals

stm32 signals

Fig 10 Arduino Mega 2650 Pinout

Arduino Mega 2650 Pinout

arduino mega 2650 shield

Now I have my US$300, 4 channel, 50MHz, 1GSa/s Digital Storage Oscilloscope Rigol Ds1504Z ready to check out the SPI waveforms.

Fig 11 - SPI waveform

spi waveform

Fig 12 - SPI Signal Routing Cable

spi signal cable

(L3)

Now I am testing Back Lit. I found that my guess was wrong. The pin BL is not LED anode, but Low level on. I used a multimeter to check that the current from BL pin to ground is 2.5mA. So I now guess BL is not a signal pin but a pull down LED power pin, sinking 2.5 mA to switch on Back Lit LED. Anyway, I am glad that now I have a huge size 2.8" white LED! :)

bak lit test

Now I have loaded the kernel module fbtft_device name = ici9341. I can also listed the module. But I found that I made another wrong guess - four SPI signal wires are not enough, I also need 3 more GPIO wires RST, DC (select Data or Command mode), and BL (back lit), ... :(

fbtft_module_loading

My ICI9341 SPI cable V2.0 does not work, because the signals Touch LCD RST and RS (Register Select) or DC (Data Command Mode Select) are missing. So I have assembled V3.0.

ici9341 cable

I will be using GPIO Gen 0 (BCM17), 1 (BCM27) , 2(BCM22) for the ICI9341, so the modprobe command is:

modprobe fbtft_device name=ici9341 gpios=reset:17,dc:27,led:22

(L4)

Update 2019may19hkt1520

I just found that my Rpi3B+ with Raspbian 2019Apr version already has a fbtft kernel driver which sadly is not the ici I ma using. So I need to build a driver myself. I found the following driver tutorial but found it very tedious. Trying it this Sunday afternoon might corrupt my Rpi OS. So I decided to stall this part of project for a couple of days, to allow me to go through slowly the tutorial.

A blazing fast display driver for SPI-based LCD displays for Raspberry Pi A, B, 2, 3 and Zero

I am still studying the juj driver document on how to build the kernel module. I have no experience of building any linux kernel module. So I am going very slowly. I have also diverted to a test on controlling a LCD 20 char x 4 line module using 4 bit interface. This is a warm up and memory refreshing exercise in case I need to switch from SPI mode to 8bit mode for faster response.

lcd2004 test 1

LCD2004 2

/ to continue, ...

References

Velleman SPI 2.8" TFT LCD ILI9341 Spec - Velleman

Velleman SPI 2.8" TFT LCD ILI9341 Schematic - Velleman

Wiring up a ILI9341 TFT Touch Screen - Rpi Forum Discussion 2015

Wiring up a ILI9341 TFT Touch Screen Post - Lallafa 2013

MI0283QT-9A 320x240px Touch Screen with ILI9341 display driver spec - Mikroe

MI0283QT-9A 320x240px Touch Screen with ILI9341 display driver User Manual - Mikroe

Linux Framebuffer drivers for small TFT LCD display modules (development ceased) - 2015

AliExpress 240 x 320 2.8" SPI TFT LCD Touch Screen (Touch Pen) ILI9341 White SPI Series - US$10

AliExpress ILI9341 240 x 320 2.8" SPI TFT LCD Touch Screen

2.8 " SPI, 36.72mm W X 48.96 mm H, 8.5 x 4.8 cm/ Conductive element: active matrix a-si TFT IC Driver: ILI9341, Backlight: White LED

Visualization direction: 6 hours, Depth of color: 262 K / 65 K

Resolution): 240 RGB * 320 5V, use with 3.3 V or 5 V logic

ILI9341 Raspberry Pi guide - pi0cket 2019feb26

Moduole Power = 3V3

Wiring (BCM Mode)

SCK - Rpi SPI Clok (GPIO 11)

MISO - Rpi SPI MISO (GPIO 9)

MOSI - Rpi SPI MOSI (GPIO 10)

CS - Rpi SPI CE0N (GPIO 8)

RST - Rpi GPIO GEN 6 (GPIO 25)

BL - Rpi GPIO GEN 1 (GPIO 18)

DC - Rpi GPIO GEN 5 (GPIO 24)

Touch Screen VMA412 User Manual

Ilitek ILI9341 a-Si TFT LCD Driver 240 RGB x 320 262K Color V1.02

AdaFruit 2.8" TFT LCD with Touchscreen Breakout Board User Guide

AdaFruit 2.8" TFT LCD with Touchscreen Breakout Board Pin Out / SPI Mode

AdaFruit 2.8" TFT LCD with Touchscreen Breakout Board w/MicroSD Socket - ILI9341 US$30

A blazing fast display driver for SPI-based LCD displays for Raspberry Pi A, B, 2, 3 and Zero - Last commit 2019Apr

User Manual For 2.8" TFT Touch Shield for Arduino with Resistive Touch Screen (TF028)

User Manual For 2.8" TFT Touch Shield for Arduino with Resistive Touch Screen

ILI9341 Raspberry Pi guide - pi0cket 2019feb26

Wave Share 3.2 inch 320x240 Touch LCD User Manua

SPI - Serial Peripheral Interface Pinout

SPI - raspberrypi.org

Using SPI0 and SPI1

WaveShare 5" Touch LCD Setup Question and tlfong01's Answer

WaveShare 7" Touch LCD Setup Question and tlfong01's Answer

Hitachi HD44780U Dot Matrix LCD Controller Datasheet Rev. 0.0

HD44780U 4x20 LCD Controller 4-bit Interface Python Program Example

AdaFruit PiTFT Plus Assembled 320x240 2.8" TFT + Resistive Touchscreen $35 https://www.adafruit.com/product/2298

[SPI Loopback test] How to check if SPI is enabled and functional on Raspi 3b+?

Arduino Meaga 2560 Pinout

Why is SPI not working on any of my Raspis?

Display and controller Experiments - WeatherStation+

ILI9341 -Single-chip SOC driver for a-TFT liquid crystal display with resolution of 240RGBx320 dots.

ILI9341 supports parallel and serial peripheral interface (SPI). The moving picture area can be specified in internal GRAM by window address function. The specified window area can be updated selectively, so that moving picture can be displayed simultaneously independent of still picture area.

Using the AdaFruit 2.8 inch TFT display

fbtft_device GitHub - Will Price Sep 18, 2017

fbtft_device has device information for all the displays it supports, with default values. These values can be changed with module parameters.

Usage

There is one required module parameter, and that is name. It specifies which display (device) to register.

eg, sudo modprobe fbtft_device name=adafruit22

fbtft_device prints information to the kernel log

$ dmesg

fbtft_device: SPI devices registered: fbtft_device: spidev spi0.0 500kHz 8 bits mode=0x00 fbtft_device: spidev spi0.1 500kHz 8 bits mode=0x00

fbtft_device: 'fb' Platform devices registered: fbtft_device:
bcm2708_fb id=-1 pdata? no

fbtft_device: Deleting spi0.0

fbtft_device: GPIOS used by 'adafruit22': fbtft_device: 'reset' = GPIO25 fbtft_device: 'led' = GPIO23

fbtft_device: SPI devices registered: fbtft_device: spidev spi0.1 500kHz 8 bits mode=0x00 fbtft_device: fb_hx8340bn spi0.0 32000kHz 8 bits mode=0x00

graphics fb1: fb_hx8340bn frame buffer, 176x220, 75 KiB video memory, 16 KiB buffer memory, fps=20, spi0.0 at 32 MHz

First it lists all SPI devices and platform devices with a name containing 'fb' (framebuffer) that was registered before the module was loaded.

Then it deletes the device connected to spi0.0 (spidev) so we can register a new one.

Then it tells which GPIOs that is associated with this display.

Then it lists which SPI devices that are currently registered (spi0.0 means SPI busnum.chipselect).

And lastly the driver is loaded.

Supported devices

The special name list will write the supported devices to the kernel log.

sudo modprobe fbtft_device name=list; dmesg | tail -30

ERROR: could not insert 'fbtft_device': Operation canceled

fbtft_device: SPI devices registered: fbtft_device: spidev spi0.1 500kHz 8 bits mode=0x00 fbtft_device: 'fb' Platform devices registered: fbtft_device: bcm2708_fb id=-1 pdata? no fbtft_device: Supported displays: fbtft_device: adafruit18 fbtft_device: adafruit18_green fbtft_device: adafruit22 ...

Parameters

busnum SPI bus number (default=0)

cs SPI chip select (default=0)

speed SPI speed in Hz (default varies among displays)

mode SPI mode (default SPI_MODE_0)

rotate Angle to rotate display counter clockwise: 0, 90, 180, 270

bgr Set BGR bit (supported by some drivers). Use if Red and Blue is swapped. Default is don't touch.

> gpios Most displays need GPIOs for signaling. To simplify configuration, pins with the same functionality has been given names:

reset - Hardware reset

dc - Data/Command (sometimes called RS) [no wonder I got confused - tlfong01]

led - Backlight

> GPIO only displays [not used for SPI mode tlfong01 2019may18]

db00-15 - Databus

cs - Chip Select

wr - Write strobe

fbtft_device have default values for these pin names (a few don't). The values can be changed with the gpios parameter. This is a comma separated array of pin/signal names and GPIO numbers. gpios=pin_name:gpio_number[,pin_name:gpio_number]

When overriding the defaults using gpios, all gpios must be specified.

Example showing the default gpio values of itdb28fb

> modprobe fbtft_device name=itdb28 gpios=reset:17,dc:1,wr:0,cs:21,db00:9,db01:11

Explaining Linux kernel modules, devices, and drivers

How to setup an LCD Touch Screen on Rpi - Waveshare

Raspberry PI OLED Library Driver

Appendices

Appendix A - ILI9341 Touch Screen Wiring V0.1 tlfong01 2019oct19hkt2217

ili9341 wiring

  • Thank you very much, I have already seen (hover over) all the tutorials provided but I do not understand how to connect "BL" (from ILI9341 Raspberry Pi guide - pi0cket) for example, I can not see it on the diagram (that you kindly highlighted me). Another remark is for pin SPI_SDO, SPI_SDA there is NC / SPI_, the NC scares me ... – Ephemeral May 14 at 7:47
  • Ah, no problem. Perhaps I can draw a diagram to explain it better. – tlfong01 May 14 at 7:50
  • It would be with great pleasure but I would not want to take up too much of your time. – Ephemeral May 14 at 7:51
  • Ah I see your problem. They are using hard to understand geek language. "NC" usually means "No Connection". “BL” usually means "Back Lit". The module has 4 white LED which can back light the background. No problem for me drawing anything. It take me very littl time. – tlfong01 May 14 at 8:20
  • Thank you very much again for all your explanations. I think at this time, GPIO9 -> LCD_RD , GPIO10 -> LCD_WR, GPIO8 -> LCD_CS but for RESET and RS (Register Select ?) no definition on pinout shematic for the raspberry. Maybe these pins can be any pin gpio (declared in the driver source file?) raspberry pinout – Ephemeral May 14 at 8:27

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