Question

SPI 2.8″ TFT LCD ILI9341

Rpi3B OK?

Answer

Well, 60% chance OK.

First thing first – check out spec and schematic.

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.

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.

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.

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 2 

Fig 3 

Fig 4 

Fig 5 

Fig 6 

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

Fig 8 – vm412 Touch LCD signals

Fig 9 – stm32 Touch LCD signals

Fig 10 Arduino Mega 2650 Pinout

Arduino Mega 2650 Pinout

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

Fig 12 – SPI Signal Routing Cable

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! 🙂

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), … 😦

/ 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 320×240 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 4×20 LCD Controller 4-bit Interface Python Program Example

AdaFruit PiTFT Plus Assembled 320×240 2.8″ TFT + Resistive Touchscreen $35https://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, 176×220, 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