windows iot touch screen spi tft display factory

so following the demo by Graham Chow who provided the basic initialization routines for a 9341 display, I took it alot further and added basic vector functions like line draw, pixel draw and character draw routines along with optimized SPI transfer routines resulting in the provieded set of libraries supporting a few more display chips

there not perfect, but are functional, they probably need more bounds checking and limit checks but they do work well and as fast as an be considering the limitations of the MS SPI implementation

some are pretty obvious as to their function, the smaller sub buttons load various images I happen to randomly pick off the internet to demonstrate the ability to load to the LCD SPI screen as well as the HDMI (See the video for a demo)

The difference here is that all this is also invokeable from the touch screen via a finger or a pen on the touch panel, in addition, if the calibration if the touch screen has not been completed it will invoke on start up and then save the results to the SD card for automatic load at next startup, not only is this hand for the touch screen but shows how any value can be saved o the SD card for future use through restarts etc.

To support this screen, a kernel-mode display-only driver was created to establish direct access to the Adafruit PiTFT display via SPI. The driver initializes the display and presents at 16 frames per second.

To allow for direct user interaction with the display, a User-Mode Touch Injection Background Service establishes touch input through an I2C bus and uses a HID injection driver to inject touch events. Touch capabilities include single point touch (pressing) and swiping. UWP XAML windows application running on the Pi will present without any changes.

Initial Setup:Set up your PC and Raspberry Pi according totheseinstructions.Next, match the pins of the Adafruit PiTFT to those of the Pi to mount the display.

Create a directory called "Deploy" on the Raspberry Pi and copy the following files from your computer to that new directory:ACPITABL.datSampleDisplay.infSampleDisplay.sys

Running the Display Driver:Install the driver package in your terminal by running the command below. You can check to make sure it"s added usingdevcon dp_enumor delete it withdevcon dp_deletedevcon dp_add C:\Deploy\sampledisplay.infRestart your Pi to see the display running.

Adding Touch:Followtheseinstructions to setup the HID Injection driver.PutHidInjector.exefrom the project folder into the deploy folder.Schedule theHidInjectorto run on boot by running this command on the Raspberry Pi via SSH:schtasks.exe /Create /SC ONSTART /TN \Microsoft\Windows\HidInjector\Start /TR %SystemRoot%\Deploy\HidInjector.exeRestart your Raspberry Pi.

With PCB plate (including power supply IC, SD), compatible with 5110 interfacePackage includes:1 * 2.4" SPI TFT LCD Display 2.4 Inch Touch Panel LCD ILI9341 240x320 5V/3.3V

The 3.5 inch RPI lcd display TFT Capacitive Touch Screen is a display module can be applied to Raspberry pi 3 B+ Pi Zero etc. It can be used as raspberry pi x window display terminals.

The RPI LCD Display TFT Capacity Touch Screen Modules used 28 pins out of raspberry pi 40 pin. When installing the module attention to align the first leg of the raspberry pi and LCD module.

Like you said, it’ll be difficult to get this display working without a datasheet. You need to know the commands for initializing the display, as well as how the display wants graphics data formatted. The SPI display used in the sample assumes bytes of data are mapped to vertical pixel columns; this display might expect a different format. You’d have to implement your own DisplaySendData() and DisplaySendCommand() functions to match the data formatting for this screen. You might be able to get a datasheet from the manufacturer if you ask them directly.

Without the datasheet, you could try sending raw 0x0000 or 0xFFFF words to the display and see if pixels start turning white/black. That would at least tell you if the display is initialized and accepting graphics data. From there you might be able to reverse engineer the data formatting by sending carefully patterned data (such as an alternating sequence of 0xFFFF and 0x0000), and seeing how the screen responds.

Jonathan Tanner | Microsoft | Windows 10 IoT Core Insider Preview Support | This posting is provided "as is" with no warranties and confers no rights.

Thanks for bringing this to my attention. It appears that the upgrade package overwrites the FBTFT drivers, in particular, the Raspberry Pi bootloader. This seems to solve the problem:

I just tested this, and it looks like the difference is how SPI is enabled. In the RPi 2 it’s enabled in raspi-config, not commented out in the blacklist file. I just updated the post so it should work now!

Looks like the only difference is in how SPI is enabled. In the new release of Raspbian, SPI is enabled in the raspi-config menu under advanced settings. In older versions of Raspbian, it is enabled by commenting out the line in the blacklist file

dwc_otg.lpm_enable=0 console=ttyAMA0,115200 console=tty1 root=/dev/mmcblk0p6 rootfstype=ext4 elevator=deadline rootwait fbtft_device.custom fbtft_device.name=waveshare32b fbtft_device.gpios=dc:22,reset:27 fbtft_device.bgr=1 fbtft_device.speed=48000000 fbcon=map:10 fbcon=font:ProFont6x11 logo.nologo dma.dmachans=0x7f35 console=tty1 consoleblank=0 fbtft_device.fps=50 fbtft_device.rotate=0

Unfortunately, their “driver” is an SD card image containing a complete installation of Raspbian which has been preconfigured to use their display. Which is fine if you’re setting up a brand new system that doesn’t need to be a specific distro, but if you’re trying to add the display to an existing Raspberry Pi, already configured the way you want it, with software installed and data present, or if you want to use a specific distro such as Octopi, then it’s not terribly helpful.

Hello..I tired to interface this lcd “https://www.crazypi.com/raspberry-pi-products/Raspberry-Pi-Accessories/32-TOUCH-DISPLAY-RASPBERRY-PI” to my Raspberry pi model B+.I got a DVD containing image for LCD in the package.I burned it to the SD card and plugged in the display.But my lcd is completly blank.But green inidcation led (ACT LED) in board is blinking.Why my LCD is Blank ?

If you have tried using the manufacturers image and the screen doesn’t work, it could be that the screen has a hardware malfunction. If the process above doesn’t work either, I would contact the manufacturer

Is your RED (POWER) LED on? I had the same problem. Green Led was blinking and screen was white. Then I noticed RED Led is off, indicating there’s something wrong with the power. I plugged into different port and it started

Yes, it may be that the screen isn’t supported. Newer screens might not have drivers yet. I do know it is possible to make your own driver but that’s above my level of knowledge :)

My Touchscreen is now working fine.The problem was for the ribbon cable on the back side of LCD.It was not connected properly.I just tighted the cable and it worked fine.Hope it will be useful tip.

Thank you for this great tutorial. I looked everywhere for this information. I have an eleduino 3.5 version A. I was able to get it working on my Pi 2 by following your tutorial and using flexfb as the screen type. I got the other settings from the image that came with the product. I did find that the ts_calibrate didn’t recognize the screen so I installed xinput-calibrator and it worked fine.

I tried the steps in this tutorial. It’s very clear and easy to follow, thank you. But it didn’t work for me, I tried setting my device to flexfb. Only got white screen.

[ 0.000000] Kernel command line: dma.dmachans=0x7f35 bcm2708_fb.fbwidth=656 bcm2708_fb.fbheight=416 bcm2709.boardrev=0xa21041 bcm2709.serial=0x631a4eae smsc95xx.macaddr=B8:27:EB:1A:4E:AE bcm2708_fb.fbswap=1 bcm2709.disk_led_gpio=47 bcm2709.disk_led_active_low=0 sdhci-bcm2708.emmc_clock_freq=250000000 vc_mem.mem_base=0x3dc00000 vc_mem.mem_size=0x3f000000 dwc_otg.lpm_enable=0 console=ttyAMA0,115200 console=tty1 root=/dev/mmcblk0p2 rootfstype=ext4 elevator=deadline rootwait fbtft_device.custom fbtft_device.name=flexfb fbtft_device.gpios=dc:22,reset:27 fbtft_device.bgr=1 fbtft_device.speed=48000000 fbcon=map:10 fbcon=font:ProFont6x11 logo.nologo dma.dmachans=0x7f35 console=tty1 consoleblank=0 fbtft_device.fps=50 fbtft_device.rotate=0

i have a watterott display (https://github.com/watterott/RPi-Display) and changed the device-name to “rpi-display”. i use a rsapberrypi 2 and hae the latest raspian image installed.

Did you check to see if your device is supported yet? The device name should be specific for your screen, as listed in the fbtft file linked to in the beginning of the post

Anyway, point 1, says to change to dev/fb1 – I don’t have fb1. Only fb0 appears to be there. is that a clue what could be wrong? I have enabled SPI (is there a command to tell if its enabled?) I have also ran spidev to troubleshot (though I haven’t a clue what I means)

Any ideas what going wrong? I am using the latest “2015-02-16-raspbian-wheezy_zip”. Enabled SPI. done all the steps. Even changed mmcblk0p2 to mmcblk0p6 as suggested by Dabomber60 (but that freezes for me)

[ 0.000000] Linux version 3.18.5-v7+ (pi@raspi2) (gcc version 4.8.3 20140106 (prerelease) (crosstool-NG linaro-1.13.1-4.8-2014.01 – Linaro GCC 2013.11) ) #1 SMP PREEMPT Fri Feb 6 23:06:57 CET 2015

It seems all appears to be working – just the LCD is still all white with a single line of coloured pixels on edge) and nothing else. Is there a way to output, like jeff G script, of touch points?

I had the same one, I finally found a driver for it here: http://www.waveshare.net/wiki/3.2inch_RPi_LCD_(B) you will need to translate the page, but unpack the driver then run sudo ./LCD-show/LCD32-show. It should reboot and all will be good with the screen :)

Can anyone let me know if the default OS image sent with the screen works with pi2 or just Pi B/B+ as i think my screen maybe broken but can’t confirm it yet as i have not had it working at all

My system: Raspberry Pi 2 Model B with Raspian Wheezy from Febuary 2015. LCD display of Sainsmart 3.2 http://www.conrad.de/ce/de/product/1283498/Raspberry-Pi-Display-Modul-Touch-Display-81-cm-32/?ref=home&rt=home&rb=1

dwc_otg.lpm_enable=0 console=ttyAMA0,115200 console=tty1 root=/dev/mmcblk0p2 rootfstype=ext4 cgroup_enable=memory elevator=deadline rootwait fbtft_device.custom fbtft_device.name=sainsmart32_spi fbtft_device.gpios=dc:24,reset:25 fbtft_device.bgr=1 fbtft_device.speed=48000000 fbcon=map:10 fbcon=font:ProFont6x11 logo.nologo dma.dmachans=0x7f35 console=tty1 consoleblank=0 fbtft_device.fps=50 fbtft_device.rotate=90

sainsmart32_spi width=320 height=240 buswidth=8 init=-1,0xCB,0x39,0x2C,0x00,0x34,0x02,-1,0xCF,0x00,0XC1,0X30,-1,0xE8,0x85,0x00,0x78,-1,0xEA,0x00,0x00,-1,0xED,0x64,0x03,0X12,0X81,-1,0xF7,0x20,-1,0xC0,0x23,-1,0xC1,0x10,-1,0xC5,0x3e,0x28,-1,0xC7,0x86,-1,0×36,0x28,-1,0x3A,0x55,-1,0xB1,0x00,0x18,-1,0xB6,0x08,0x82,0x27,-1,0xF2,0x00,-1,0×26,0x01,-1,0xE0,0x0F,0x31,0x2B,0x0C,0x0E,0x08,0x4E,0xF1,0x37,0x07,0x10,0x03,0x0E,0x09,0x00,-1,0XE1,0x00,0x0E,0x14,0x03,0x11,0x07,0x31,0xC1,0x48,0x08,0x0F,0x0C,0x31,0x36,0x0F,-1,0×11,-2,120,-1,0×29,-1,0x2c,-3

The LCD display shows the raspberry correctly. However, the touch screen input does not work. The mouse pointer can I move correctly with your finger, but I can not select things (function of the left mouse button).

Can someone upload SD card image that works with RBP2 ? My idea is to use Eleduino TFT as additional screen and play movies via HDMI.. is it possible?

Expecting this would builtin driver module within kernel and help with avoiding mistakenly overwriting anything. But with this is cause LCD screen to go blank white and no boot activity. Also noticed on HDMI it get stuck on Initial rainbow screen and stuck on that.

Does anyone tried splash boot screen with waveshare v4 LCD and Rpi2? I tried to follow some example from https://github.com/notro/fbtft/wiki/Bootsplash but no success.

fbtft_device name=waveshare32b gpios=dc:22,reset:27 speed=48000000 width=320 height=240 buswidth=8 init=-1,0xCB,0x39,0x2C,0x00,0x34,0x02,-1,0xCF,0x00,0XC1,0X30,-1,0xE8,0x85,0x00,0x78,-1,0xEA,0x00,0x00,-1,0xED,0x64,0x03,0X12,0X81,-1,0xF7,0x20,-1,0xC0,0x23,-1,0xC1,0x10,-1,0xC5,0x3e,0x28,-1,0xC7,0x86,-1,0×36,0x28,-1,0x3A,0x55,-1,0xB1,0x00,0x18,-1,0xB6,0x08,0x82,0x27,-1,0xF2,0x00,-1,0×26,0x01,-1,0xE0,0x0F,0x31,0x2B,0x0C,0x0E,0x08,0x4E,0xF1,0x37,0x07,0x10,0x03,0x0E,0x09,0x00,-1,0XE1,0x00,0x0E,0x14,0x03,0x11,0x07,0x31,0xC1,0x48,0x08,0x0F,0x0C,0x31,0x36,0x0F,-1,0×11,-2,120,-1,0×29,-1,0x2c,-3

After following this tut to the letter on a brand new image of Raspian, I find that the touch driver does not function. Anyone experience the same? Basically all I did was image a current copy of rasping, did a apt-get upgrade, and then did this tutorial. Then the touch driver does not work, meaning the pointer does not respond.

The reason I did this was because on a production version of my system I added the 3.2 screen and it worked great except for the x-axis. So I wanted to see if there was something in my system that was interfering or if this is another error. Now with a raw rasping the driver does not work at all. I wonder if the touch pin has changed since the kernel is using BCM pins instead of GPIO pin numbers?

I have exactly the same problem. I also installed a new version of Raspbian, and the LCD part works fine (except all the windows are way too large), but the touch part doesn’t work at all… I’m using Waveshare Spotpear 3.2″ V4.

I remember that I plugged in the screen wrongly one time, before configuring any of the GPIO pins. Can this have damaged the screen? Still it’s weird that the display part works well and the touch part not at all.

I do not think that has anything to do with it. Other than power pins, the rest are communication. If it still works then you are good. No, there is something else. I do suspect it us related to the BCM pin numbering. The real question is… Why isnt the eeveloper responding? I have since abandoned this TFT because of his lack of response.

Touch actually goes through one of the SPI pins I think. Either the driver is toast with the required kernel update or the driver is using the wrong pin. It is very likely the this works well with previous raspian versions, but not with the new B+ and with the new kernel.

I am trying to use the sainsmart 2.8″ lcd sold through microcenter, using the sainsmart32_spi … seems to have the same pinouts, should I be able to get this to work? I am stuck at the white out screen on the lcd, doesn’t seem to recognize the module either.

Unfortunately I’ve tried that ( a few times actually) but the file still doesn’t exist. Thanks very much for the assistance anyway. I must be doing something wrong. My Raspian came from a Noobs installation, I’m wondering if I should try installing the OS from somewhere else. My LCD screen didn’t come with a CD or any docs so I’m completely in the dark here.

I have the waveshare 3.5 and what to use it only as a secondary screen by putting measurement data with a c program on the screen. Is there any solution?

Ok, what am I doing wrong. I am using a fresh install of the newest raspbian, on a Pi 2. After doing the first two steps and rebooting I get the rainbow screen, then the boot up process, and then my screen just goes black with a flashing cursor in the top left. I am not able to enter any commands or anything…like the pi is halting just after boot up. Any thoughts/suggestions would be greatly appreciated. Thanks.

Well figured out that step 1 was causing my problems. I’m guessing it is shutting off my hdmi feed and trying to switch it over to the SPI, am I guessing right? If so, not sure how I’m suppose to complete the rest of the steps if my hdmi output gets turned off before the LCD is actually set up to work…that sounds kind of smartass-like, which is not my intention, just looking for some clarification on what is going on in that first step as I am fairly new to this stuff. Thanks.

Here is a link to an updated image from waveshare. Upon install it got the display up and running, but I still do not have touch functionality. I’ve been playing around with it, but it has been to no avail…hopefully someone better at this stuff from me can get the touch working.

Hi I am making a project for school,using the raspberry pi b+ and waveshare spotpare 3.2b. Everything works except the touch input doesn’t work. Any help would be appreciated very much.

Thanks for the tutorial. It works, but I get the boot/command line stuff on the HDMI monitor and the LCD only comes on when I do startx. Is there a way to get everything to appear on the LCD screen?

I am trying to get this same screen to work with the image of RetroPie 2.6 and it won’t work. I have followed all the steps and nothing, please help I an kinda a noob.

I have a Tontec 7 inch touchscreen with a Raspberry Pi 2 B. After following the instructions the touch screen is functioning but not properly… The only are that works is the upper left (and only a small area of that). I tried changing the width and height in the modules but it didnt change anything. Also the xy seems to be reversed, I changed the swap_xy to 1 but again no change on the screen.

Now the OS freezes at the emulation station loading screen, and if I connect my lcd it gives me a lot of error messages which I can only see on the 3.2 inch screen.

hi i have the same screen with a raspberry pi 2 im trying to run retro pie but it wont show ..however it shows all the commands …but i cant get it to show the gui …if u guys can make an image or something please i have been in this pain for two weeks already thank you

Damn.. I thought I was kickin ass haha. I am using the SainSmart 3.2″.. the backlight is lit up and the pi was booting and everything just fine but on the final reboot it gets hung and says “nonblocking pool is initialized” ?? No idea what that means. But it’s def just frozen at this point.. on my main screen, and just the backlight is on the SainSmart.

This was an excellent tutorial. I have gotten an output to the screen, but no touchscreen usage . I have the Waveshare SpotPear 3.2 Inch LCD V4 screen, but using Raspberry PI 2 with wheezy. Any ideas?

Thanks a lot for this article. Very clear and easy . I am new in pi’s world and my 3.2″ screen is working fine. I rotate 90 º and works. I can use mouse and so on.Not problems.

I filed the steps to calibrate the screen but it did not work.I think because it did not find the TFT pin, because I think the touch problem is the assigned pin to control it changed.

I actually used the driver from here http://www.waveshare.com/wiki/3.2inch_RPi_LCD_(B) , from a new wheezy build, did nothing except enable SPI in config, install driver, and change mmcblk0p2 to mmcblk0p6 in cmdline.txt and it all worked, no drama.

Hi I managed to set up my touch screen ok but I now have the issue that everything desktop fits fine but the windows I open are all huge and I can’t remember how to change the size and cannot see the option in desktop preferences any idea what I have to do and is it at all possible to install kodi to run through the raspbian is as this would be a lot my useful than having to keep swapping os on every boot up many thanks in advanced hope you can help me

Advice to all who have the drivers from the (touch)screen manufacturer and cannot obtain those otherwise: you can skip everything and go to the update steps skipping the kernel and kernel modules update (as mentioned by the author) so that you don’t override the preinstalled drivers. I have a Waveshare 3.5″ RPi v3 (not the 3.2″ supported by notro’s drivers) and actually managed without any problems to get notro’s drivers make it work. However I am still reading about the xinput and xinput-calibrator to figure out how to include it as a kernel module so that I can compile my own kernel and add it there.

i have raspberry pi 2 with 3.2 inch rpi lcd v4 waveshare spotpear.i have done as per your instructions.the display is working but touch screen not working.error shows waveshare32b module not found as well as touch screen module not found messages.

Unfortunately I have lost the Touch facility on my Waveshare 3.5″ LCD Touchscreen? Can you offer any reasons as to why? I copied the Raspbian image to my Raspberry Pi from the Waveshare website first of all. The Touchscreen displays but is not reactive with any touch

I have purchased a raspberry pi B+ total kit and waveshare 3.2 TFT display online. In the package i have been given a pre-loaded NOOBS installed SD card. I did not even start anything yet. What should i do what r the things needed and how to connect the display i really want to know. I need help as i don’t know anything. Does the above solution help or will u suggest something………………..

Hi great article thanks. I am trying to get a waveshare 7 inch LCD with capacitive touch running it works with the suppled image but if you upgrade it breaks the capacitive touch. I have a sense-hat and GPS which require the latest kernel and RASPIAN image and the install program for the screen replaces the /lib/modules directory and the kernel with older ones. I need to be able to install the touch drivers into a new clean OS can anyone give me some pointers? Thanks

I should add that the screen is plugged into the HDMI port and always works. The capacitive touch is driven from the USB port which also supplies power.

For anyone who have those unbranded cheap TFT touch modules and cannot get it to work with this guide, I had success on my 3.5″ with the following steps: http://pastebin.com/89qmFbPB

I have the WaveShare 3.5 (A) and cannot get it to work with the Kali Linux with TFT for Raspberry Pi. Have anybody gotten the A to work? (Not the B, theres instructions for the B already and dont work with A)

So I have the original image that came with my screen and it works fine with the LCD but my problem is that I want to use my LCD screen with other distros (at this time I am trying to use it with Kali Linux with TFT support by default https://www.offensive-security.com/kali-linux-vmware-arm-image-download/) What do I have to do to transfer the needed files from the original image that WORKS with the screen and use them with another image?

I originally bought this bundle http://www.amazon.com/gp/product/B013E0IJUK?psc=1&redirect=true&ref_=oh_aui_detailpage_o02_s00 with an RPi LCD V3 and no extra documentation on the specifics on the chipset. I tried with the bftft drivers but since I have no idea what to call this screen I just suppose it isn’t supported.

After 4 lost days I just decided to get another screen, a Waveshare 3.2 (just like the one on this tutorial), I’ll follow these steps and see if it work for me.

I’ve followed your instructions and am only getting a white screen stil. I am using the Osoyoo 3.5 inch touchscreen from Amazon. http://www.amazon.com/gp/product/B013E0IJVE?psc=1&redirect=true&ref_=oh_aui_detailpage_o01_s00

I’m not sure if the Jessie kernel is compatible – can anyone please confirm or not ?? Adafruit states that their setup for TFT screens are Wheezy only ; is this a different setup ??

I am using the same LCD and followed your tutorial. Have your tested the guide lately? Are you certain that it works? I see the boot messages on console but I get white screen as GUI starts.

Oct 16 17:38:48 spare kernel: [ 12.544859] graphics fb1: fb_ili9340 frame buffer, 320×240, 150 KiB video memory, 4 KiB DMA buffer memory, fps=50, spi0.0 at 48 MHz

After I rebooted in step 3, my raspberry pi won’t boot up again. It goes thru the process of booting and the text scrolls down and every thing says “ok”. Then instead of going to GUI it just guys to a black screen on my monitor with a blinking underscore in the top left corner. Anyway to get around this? or should I start over with a fresh disk image??

Please check out my answer, it may help you if it works. I’m not in that case but I’m assuming that the desktop environment simply doesn’t automatically start running anymore… This can be changed in the raspi-setup

I have tried to set up waveshare 32b on my Pi B using the latest Raspian download. I learned a lot in the process using Windows Putty, Nano etc. I have repeated the setup process several times from scratch and included the corrections for possible overwriting. My Waveshare SpotPear 3.2 inch RPi LCD V4 just shows a white screen. Any suggestions?

I’d suggest that you use the included installation disk to make a clean install on another SD card to see if the screen itself works fine or not, then try to repeat the process of installation after upgrading

There was no disk included. I asked for drivers and was given a download link to the image file. After down loading this I tried it and still got just a white screen. The HDMI monitor locks partway though the boot. I can still log in to pi using putty from my PC.

This process worked for me except for two things. The screen only shows 25* of any page so the most important buttons are inaccessible, and now the Wifi does not work and cannot be activated where it worked fine before the reboot. Any suggestions?

Hi, I am using raspberry pi 2 with raspbian jessie installed. I the waveshare spotpear 3.2 v4. The above instructions are not working. and after completing the steps there was no display from hdmi or lcd. One things to notify is.: the etc/modules files only had i2c-dev and not snd-bcm2835.

Sir, Your post has very useful to me. i am using Tinylcd. but i cant get display. i am performing all the steps in your post. i cant get touch controller information from the product website and also i am using RASPberryPi B+ model. could u please give me best solution to my work. Than you.

Hi, what if you dont know the make of your screen, i purchased via Ebay, and it is unbranded, the contact speaks barely any English and keeps linking me to a custom kernal download.

i installed android OS in raspberry pi 2. can i use same LCD touch screen set up for android installed raspberry pi 2 which you are used for raspbian.

I have KeDei 3.5 inch TFT version 4.0 by Osoyoo. (released after January 1 2016) how do i get it working with vanilla Raspbian Jessie (do not want to install the image sent by the seller)

I’m trying to use an original Raspberry Pi model B with a cheap 3.5 inch 320×480 LCD which allegedly was manufactured to work with the Pi and has the correct fittings to fit over the GPIO pins. The operating system is the latest, downloaded yesterday and installed with NOOBS. I can’t get past step 2 of this guidance. When I reboot after using raspi-config I can see text generated as the Pi boots, then the HDMI fed screen goes blank apart from a flashing cursor in the top left hand corner. The LCD just remains white with nothing else on it. I have missed out step 1 and rebooted after step 2 and the screen functions as I would expect. Does anyone have any ideas please?

Thanks for the great tutorial. I do have a question. Once you install the drivers for the lcd are you effectively disabiling the hdmi port or is it still available to use and will the pi function with both displays. I have a pi 3

Thanks for the guide, have been doing this with my son but once we leave raspi config and reboot all we get is a black screen with a flashing white horizontal line (dash). Can you help? I have looked in the comments at the end of the article but no one else appears to have this issue.

I have a raspberry pi 2 with waveshare screenn 3.5 inches. Isn’t it the same instructions. But it isnt working, all i get is a white screen, and the red led on the pi is on. The green LED isnot working.

i am sorry, but i am a naive , and i have this question, can we upload any file into it for the display? like have a software in which if i tap it gives back a feedback to the code?

My Rpi3 gets “ERROR: could not insert ‘spi_bcm2708’: No such device” after I enable SPI in the raspi-config.My Rpi3 is freezing on the rainbow screen after I reboot at the end of step 3. I’ve tried adding boot_delay=1 to config.txt.

if any interested, now i have a raspian image working on raspberry 3 with Waveshare 3.5, also with sdr support for dongles and FreqShow working perfectly on touch

I tried following your tutorial but I got stuck right at the first step… I enter sudo nano /usr/share/X11/xorg.conf.d/99-fbturbo.conf the whole screen is blank except for the command list at the bottom…

I’d like to find the driver software for my 7″ LCD with touch (official Pi unit) so that I can use it in buildroot. I wanted to make sure this kernel is the one before I started digging further.

Every time I reboot after step 3 I get the rainbow screen of death (lost the kernel) and have to reimage my card and start over. Anybody had this happen and have a solution?

I started through your tutorial and completed step 3 and rebooted. After the Raspberry screen and some of the boot text on my HDMI monitor, I now have a black HDMI monitor and a white screen on my LCD. Does this mean that the bootloader was overwritten or something else is wrong? How am I supposed to enter in the proposed fixes to the bootloader, when I can’t get the RPi to boot? Do I have to interrupt the boot process at some point to reinstall the bootloader or what?

Its a script. Download and instead of running sudo ./LCD4-show run cat ./LCD4-show to simply display what it does without actually running it. The commands are fairly simple modifying a few files. I actually saved the LCD-show.tar.gz on my own server for faster future download but also for backup as it saved me tons of hours (if that’s a measuring unit for time :) )

I’m using RasPi Zero with latest (as of last week) Jessie Raspbian. Did you run the script? If it didn’t work and you have modified other files in the process of making it work, I would recommend installing a fresh installed image on a new card and running the script. Can you suspect the screen being faulty or got “burned” in the process?

i bought a 3.5 inch tft lcd screen from banggood. and i have installed raspian jessie, the latest version, in my sd card. but when i power on my Pi, only a white backlit screen comes. there are no images or graphics whatsoever.

Of course. Raspbian Jessie does not come with the drivers needed to talk to the screen. See my previous comment (September 22, 2016 at 11:54 am) and follow it.

The owner of this article should including a WARNING in the header that if someone follows the steps, they will install a deprecated driver (which is only visible as tiny text on its gethub page here https://github.com/notro/rpi-firmware). This driver after install will break Raspberry Pi and the SD card will need to be reimaged, for some less experienced users, this could also mean lost work if they failed to backup their code or resources. On windows, it requires installing Linux reader software and it takes a long time to fix this f**kup which could easily have been avoided if the author had and sense of responsibility.

PLEASE DELETE this article. You have great power with this article showing up for so many people in their search results, and you display ZERO responsibility. This is terrible!

I have done every thing right but the only major problem is that the screen is still white and my raspberrypi freezes after a line of code when booting up and I cant get in with SSH

Will your system work with my SainSmart 2.8″ 2.8 inch TFT LCD 240×320 Arduino DUE MEGA2560 R3 Raspberry Pi ? I would like to know before not be able to back out. Thanks, Lee

I know I will end up regretting this, but how do I change fb0 to fb1? I’m on the screen that has all the info, but no way to change it. Am I looking for a file? I have had my screen for MONTHS and I can’t do anything with my pi or the screen. I am >< close to smashing both. COMPLETE WASTE OF MONEY so far!!

hello. I really appreciate your blog post. I have a raspberry pi 3 B. I have been unable to get my waveshare 3.2 screen to work.I am at a complete loss for what to do. I do step 2 I change fb0 to fb1 and then follow your directions I don’t get the prompt to reboot; however, I do it manually with sudo reboot. that works fine then I complete step three and that works just fine; however once I reboot from getting those drivers and when I attempt to reboot it is unsuccessful and then my whole raspberry pi will not restart. then when I power it back on it will just shut back off. I then have to redo noobs onto a new SD card I would GREATLY appreciate anyones help

I ‘m actually using a LCD Waveshare3.2” , I followed your steps to setup the lcd touchscreen for my rpi and it work but I have a problem with the resolution because if I open a repertory I do not see the whole contents on the screen .

hi! thank you for this post…. I was wondering if all the raspberry pi’s gpio are being held by this screen or do we have any of those availables for use??

it worked. but the resolution is for bigger screens. i got the menubar small, but the rest appears too big , and out of screen. the wastebasket icon is 1/6 of my 3.2″ screen. wich HAS the resolution capability too display the whole desktop. But i’m a PI newby and dunno how to adjust the screen resolution on this display. anybody?

hey Thanks for this good post …I have capacitive touchscreen which i brought from the link below..can you guide how i can configure the kernel modules…It will be very helpful for me…Thanks

hey Thanks for this good post …I have capacitive touchscreen which i brought from the link below..can you guide how i can configure the kernel modules…It will be very helpful for me…Thanks

I did a 5inch LCD for my raspberry pi. I dont use the touchscreen so i didnt have to install any drivers. It works out of the box but doesnt cover the whole screen unless you open the terminal and do:

HI I have my RPI running Pi Presents on a view sonic TD2230 Touchscreen. It all works fine, touching the click areas can navigate you thru my presentation, The problem arises when you use multitouch gestures like you would on a iPhone. Pinch or expand etc… and then all touch ability goes away. I can still control the presentation via a mouse, but I don’t get touch control back until I either relaunch Pi Presents, or if I unplug and plug the usb cable going to the touchscreen.

Could you provide me with a os image of open elec that you already built for the waveshare spotpear v4 3.2 inch touchscreen,because I cannot make sense of your website’s instructions?

After I did the step that “INSTALL THE FBTFT DRIVERS” and then reboot, my raspberry pi couldn’t boot successfully and the green light is always on, could you help me solve this problem? Thank you.

Orient Display sunlight readable TFT displays can be categorized into high brightness TFT displays, high contrast IPS displays, transflective TFT displays, Blanview TFT displays etc.

The brightness of our standard high brightness TFT displays can be from 700 to 1000 nits. With proper adding brightness enhancement film (BEF) and double brightness enhancement film (DBEF) and adjustment of the LED chips, Orient Display high brightness TFT products can achieve 1,500 to 2,000 nits or even higher luminance. Orient Display have special thermal management design to reduce the heat release and largely extend LED life time and reduce energy consumption.

Our high contrast and wide viewing angle IPS displays can achieve contrast ratio higher than 1000:1 which can make readability under strong sunlight with lower backlight luminance. High brightness IPS displays have been widely accepted by our customers with its superb display quality and it has become one of the best sellers in all our display category.Transflective display is an old monochrome display technology but it has been utilized in our color TFT line for sunlight readable application. Orient Display has 2.4” and 3.5” to choose from.

Blanview TFT displays are the new technology developed by Ortustech in Japan. It can provide around 40% of energy consumption for TFT panels which can use smaller rechargeable or disposable batteries and generate less heat. The price is also lower than traditional transflective TFT displays. Orient Display is partnering with the technology inventor to provide 4.3” and 5.0”.

Orient Display can also provide full customized or part customized solutions for our customers to enhance the viewing experience. Orient Display can provide all the different kinds of surface treatments, such as AR (Anti-reflection); AG (Anti-glare), AF (Anti-finger print or Anti-smudge); AS (Anti-smashing); AM (Anti-microbial) etc. Orient Display can also provide both dry bonding (OCA, Optical Clear Adhesive), or wet bonding (OCR, Optical Clear Resin and OCG, Optical Clear Glue) to get rid of light reflective in air bonding products to make the products much more readable under sunlight and be more robust.

Touch panels have been a much better human machine interface which become widely popular. Orient Display has been investing heavy for capacitive touch screen sensor manufacturing capacity. Now, Orient Display factory is No.1 in the world for automotive capacitive touch screen which took around 18% market share in the world automotive market.

Based on the above three types of touch panel technology, Orient Display can also add different kinds of features like different material glove touch, water environment touch, salt water environment touch, hover touch, 3D (force) touch, haptic touch etc. Orient Display can also provide from very low cost fixed area button touch, single (one) finger touch, double finger (one finger+ one gesture) touch, 5 finger touch, 10 points touch or even 16 points touch.

Considering the different shapes of the touch surface requirements, Orient Display can produce different shapes of 2D touch panel (rectangle, round, octagon etc.), or 2.5D touch screen (round edge and flat surface) or 3D (totally curved surface) touch panel.

Considering different strength requirements, Orient Display can provide low cost chemical tampered soda-lime glass, Asahi (AGC) Dragontrail glass and Corning high end Gorilla glass. With different thickness requirement, Orient Display can provide the thinnest 0.5mm OGS touch panel, to thickness more than 10mm tempered glass to prevent vandalizing, or different kinds of plastic touch panel to provide glass piece free (fear) or flexible substrates need.

Of course, Orient Display can also offer traditional RTP (Resistive Touch Panel) of 4-wire, 5-wire, 8-wire through our partners, which Orient Display can do integration to resistive touch screen displays.

Engineers are always looking for lower cost, faster, more convenient interfaces to transmit signals and to accept data and commands. The numbers of available interfaces available in the market can be dazzling. Orient Display follows market trends to produce various kind of interfaces for our customers to choose.

Genetic Interfaces: Those are the interfaces which display or touch controller manufacturers provide, including parallel, MCU, SPI(,Serial Peripheral Interface), I2C, RGB (Red Green Blue), MIPI (Mobile Industry Processor Interface), LVDS (Low-Voltage Differential Signaling), eDP ( Embedded DisplayPort) etc. Orient Display has technologies to make the above interface exchangeable.

High Level Interfaces: Orient Display has technologies to make more advanced interfaces which are more convenient to non-display engineers, such as RS232, RS485, USB, VGA, HDMI etc. more information can be found in our serious products. TFT modules, Arduino TFT display, Raspberry Pi TFT display, Control Board.

※Price Increase NotificationThe TFT glass cell makers such as Tianma,Hanstar,BOE,Innolux has reduced or stopped the production of small and medium-sized tft glass cell from August-2020 due to the low profit and focus on the size of LCD TV,Tablet PC and Smart Phone .It results the glass cell price in the market is extremely high,and the same situation happens in IC industry.We deeply regret that rapidly rising costs for glass cell and controller IC necessitate our raising the price of tft display.We have made every attempt to avoid the increase, we could accept no profit from the beginning,but the price is going up frequently ,we"re now losing a lot of money. We have no choice if we want to survive. There is no certain answer for when the price would go back to the normal.We guess it will take at least 6 months until these glass cell and semiconductor manufacturing companies recover the production schedule. (Mar-03-2021)

ER-TFTV043A3-3 is 480x272 pixel 4.3 inch color tft lcd display for the Raspberry Pi with optional USB port resistive or capacitive touch panel screen,optional USB cable and HDMI cable. Of course ,it is not limited to the Raspberry Pi ,it can be used for all the universal HDMI port hardwares such as mini PCs, Raspberry Pi, BB Black, Banana Pi, as well as general desktop computers.

When works with Raspberry Pi, supports Raspbian, Ubuntu, WIN10 IOT, single touch and driver free.When work as a computer monitor, supports Windows 10/8.1/8/7, five-points touch, and driver free.Multi languages OSD menu for power management,.brightness and contrast adjustment, etc.

In these videos, the SPI (GPIO) bus is referred to being the bottleneck. SPI based displays update over a serial data bus, transmitting one bit per clock cycle on the bus. A 320x240x16bpp display hence requires a SPI bus clock rate of 73.728MHz to achieve a full 60fps refresh frequency. Not many SPI LCD controllers can communicate this fast in practice, but are constrained to e.g. a 16-50MHz SPI bus clock speed, capping the maximum update rate significantly. Can we do anything about this?

The fbcp-ili9341 project started out as a display driver for the Adafruit 2.8" 320x240 TFT w/ Touch screen for Raspberry Pi display that utilizes the ILI9341 controller. On that display, fbcp-ili9341 can achieve a 60fps update rate, depending on the content that is being displayed. Check out these videos for examples of the driver in action:

Given that the SPI bus can be so constrained on bandwidth, how come fbcp-ili9341 seems to be able to update at up to 60fps? The way this is achieved is by what could be called adaptive display stream updates. Instead of uploading each pixel at each display refresh cycle, only the actually changed pixels on screen are submitted to the display. This is doable because the ILI9341 controller, as many other popular controllers, have communication interface functions that allow specifying partial screen updates, down to subrectangles or even individual pixel levels. This allows beating the bandwidth limit: for example in Quake, even though it is a fast pacing game, on average only about 46% of all pixels on screen change each rendered frame. Some parts, such as the UI stay practically constant across multiple frames.

A hybrid of both Polled Mode SPI and DMA based transfers are utilized. Long sequential transfer bursts are performed using DMA, and when DMA would have too much latency, Polled Mode SPI is applied instead.

Undocumented BCM2835 features are used to squeeze out maximum bandwidth: SPI CDIV is driven at even numbers (and not just powers of two), and the SPI DLEN register is forced in non-DMA mode to avoid an idle 9th clock cycle for each transferred byte.

Good old interlacing is added into the mix: if the amount of pixels that needs updating is detected to be too much that the SPI bus cannot handle it, the driver adaptively resorts to doing an interlaced update, uploading even and odd scanlines at subsequent frames. Once the number of pending pixels to write returns to manageable amounts, progressive updating is resumed. This effectively doubles the maximum display update rate. (If you do not like the visual appearance that interlacing causes, it is easy to disable this by uncommenting the line #define NO_INTERLACING in file config.h)

A number of other micro-optimization techniques are used, such as batch updating rectangular spans of pixels, merging disjoint-but-close spans of pixels on the same scanline, and latching Column and Page End Addresses to bottom-right corner of the display to be able to cut CASET and PASET messages in mid-communication.

The result is that the SPI bus can be kept close to 100% saturation, ~94-97% usual, to maximize the utilization rate of the bus, while only transmitting practically the minimum number of bytes needed to describe each new frame.

This driver does not utilize the notro/fbtft framebuffer driver, so that needs to be disabled if active. That is, if your /boot/config.txt file has lines that look something like dtoverlay=pitft28r, ..., dtoverlay=waveshare32b, ... or dtoverlay=flexfb, ..., those should be removed.

This program neither utilizes the default SPI driver, so a line such as dtparam=spi=on in /boot/config.txt should also be removed so that it will not cause conflicts.

Likewise, if you have any touch controller related dtoverlays active, such as dtoverlay=ads7846,... or anything that has a penirq= directive, those should be removed as well to avoid conflicts. It would be possible to add touch support to fbcp-ili9341 if someone wants to take a stab at it.

If you have been running existing fbcp driver, make sure to remove that e.g. via a sudo pkill fbcp first (while running in SSH prompt or connected to a HDMI display), these two cannot run at the same time. If /etc/rc.local or /etc/init.d contains an entry to start up fbcp at boot, that directive should be deleted.

When using one of the displays that stack on top of the Pi that are already recognized by fbcp-ili9341, you don"t need to specify the GPIO pin assignments, but fbcp-ili9341 code already has those. Pass one of the following CMake directives for the hats:

-DPIRATE_AUDIO_ST7789_HAT=ON: If specified, targets a Pirate Audio 240x240, 1.3inch IPS LCD display HAT for Raspberry Pi with ST7789 display controller

-DKEDEI_V63_MPI3501=ON: If specified, targets a KeDei 3.5 inch SPI TFTLCD 480*320 16bit/18bit version 6.3 2018/4/9 display with MPI3501 display controller.

If you connected wires directly on the Pi instead of using a Hat from the above list, you will need to use the configuration directives below. In addition to specifying the display, you will also need to tell fbcp-ili9341 which GPIO pins you wired the connections to. To configure the display controller, pass one of:

-DILI9341=ON: If you are running on any other generic ILI9341 display, or on Waveshare32b display that is standalone and not on the FreeplayTech CM3/Zero device, pass this flag.

-DILI9340=ON: If you have a ILI9340 display, pass this directive. ILI9340 and ILI9341 chipsets are very similar, but ILI9340 doesn"t support all of the features on ILI9341 and they will be disabled or downgraded.

-DILI9486L=ON: If you have a ILI9486L display, pass this directive. Note that ILI9486 and ILI9486L are quite different, mutually incompatible controller chips, so be careful here identifying which one you have. (or just try both, should not break if you misidentified)

-DGPIO_TFT_DATA_CONTROL=number: Specifies/overrides which GPIO pin to use for the Data/Control (DC) line on the 4-wire SPI communication. This pin number is specified in BCM pin numbers. If you have a 3-wire SPI display that does not have a Data/Control line, set this value to -1, i.e. -DGPIO_TFT_DATA_CONTROL=-1 to tell fbcp-ili9341 to target 3-wire ("9-bit") SPI communication.

-DGPIO_TFT_RESET_PIN=number: Specifies/overrides which GPIO pin to use for the display Reset line. This pin number is specified in BCM pin numbers. If omitted, it is assumed that the display does not have a Reset pin, and is always on.

-DGPIO_TFT_BACKLIGHT=number: Specifies/overrides which GPIO pin to use for the display backlight line. This pin number is specified in BCM pin numbers. If omitted, it is assumed that the display does not have a GPIO-controlled backlight pin, and is always on. If setting this, also see the #define BACKLIGHT_CONTROL option in config.h.

fbcp-ili9341 always uses the hardware SPI0 port, so the MISO, MOSI, CLK and CE0 pins are always the same and cannot be changed. The MISO pin is actually not used (at the moment at least), so you can just skip connecting that one. If your display is a rogue one that ignores the chip enable line, you can omit connecting that as well, or might also be able to get away by connecting that to ground if you are hard pressed to simplify wiring (depending on the display).

To get good performance out of the displays, you will drive the displays far out above the rated speed specs (the rated specs yield about ~10fps depending on display). Due to this, you will need to explicitly configure the target speed you want to drive the display at, because due to manufacturing variances each display copy reaches a different maximum speed. There is no "default speed" that fbcp-ili9341 would use. Setting the speed is done via the option

-DSPI_BUS_CLOCK_DIVISOR=even_number: Sets the clock divisor number which along with the Pi core_freq= option in /boot/config.txt specifies the overall speed that the display SPI communication bus is driven at. SPI_frequency = core_freq/divisor. SPI_BUS_CLOCK_DIVISOR must be an even number. Default Pi 3B and Zero W core_freq is 400MHz, and generally a value -DSPI_BUS_CLOCK_DIVISOR=6 seems to be the best that a ILI9341 display can do. Try a larger value if the display shows corrupt output, or a smaller value to get higher bandwidth. See ili9341.h and waveshare35b.h for data points on tuning the maximum SPI performance. Safe initial value could be something like -DSPI_BUS_CLOCK_DIVISOR=30.

-DBACKLIGHT_CONTROL=ON: If set, enables fbcp-ili9341 to control the display backlight in the given backlight pin. The display will go to sleep after a period of inactivity on the screen. If not, backlight is not touched.

-DDISPLAY_CROPPED_INSTEAD_OF_SCALING=ON: If set, and source video frame is larger than the SPI display video resolution, the source video is presented on the SPI display by cropping out parts of it in all directions, instead of scaling to fit.

-DDISPLAY_BREAK_ASPECT_RATIO_WHEN_SCALING=ON: When scaling source video to SPI display, scaling is performed by default following aspect ratio, adding letterboxes/pillarboxes as needed. If this is set, the stretching is performed breaking aspect ratio.

-DSTATISTICS=number: Specifies the level of overlay statistics to show on screen. 0: disabled, 1: enabled, 2: enabled, and show frame rate interval graph as well. Default value is 1 (enabled).

-DDISPLAY_SWAP_BGR=ON: If this option is passed, red and blue color channels are reversed (RGB<->BGR) swap. Some displays have an opposite color panel subpixel layout that the display controller does not automatically account for, so define this if blue and red are mixed up.

-DDISPLAY_INVERT_COLORS=ON: If this option is passed, pixel color value interpretation is reversed (white=0, black=31/63). Default: black=0, white=31/63. Pass this option if the display image looks like a color negative of the actual colors.

-DLOW_BATTERY_PIN=: Specifies a GPIO pin that can be polled to get the battery state. By default, when this is set, a low battery icon will be displayed if the pin is pulled low (see config.h for ways in which this can be tweaked).

Here is a full example of what to type to build and run, if you have the Adafruit 2.8" 320x240 TFT w/ Touch screen for Raspberry Pi with ILI9341 controller:

If the above does not work, try specifying -DSPI_BUS_CLOCK_DIVISOR=8 or =10 to make the display run a little slower, or try with -DUSE_DMA_TRANSFERS=OFF to troubleshoot if DMA might be the issue. If you are using another display controller than ILI9341, using a much higher value, like 30 or 40 may be needed. When changing CMake options, you can reissue the CMake directive line without having to reclone or recreate the build directory. However you may need to manually delete file CMakeCache.txt between changing options to avoid CMake remembering old settings.

If the size of the default HDMI output /dev/fb0 framebuffer differs from the resolution of the display, the source video size will by default be rescaled to fit to the size of the SPI display. fbcp-ili9341 will manage setting up this rescaling if needed, and it will be done by the GPU, so performance should not be impacted too much. However if the resolutions do not match, small text will probably appear illegible. The resizing will be done in aspect ratio preserving manner, so if the aspect ratios do not match, either horizontal or vertical black borders will appear on the display. If you do not use the HDMI output at all, it is probably best to configure the HDMI output to match the SPI display size so that rescaling will not be needed. This can be done by setting the following lines in /boot/config.txt:

These lines hint native applications about the default display mode, and let them render to the native resolution of the TFT display. This can however prevent the use of the HDMI connector, if the HDMI connected display does not support such a small resolution. As a compromise, if both HDMI and SPI displays want to be used at the same time, some other compatible resolution such as 640x480 can be used. See Raspberry Pi HDMI documentation for the available options to do this.

The refresh speed of the display is dictated by the clock speed of the SPI bus that the display is connected to. Due to the way the BCM2835 chip on Raspberry Pi works, there does not exist a simple speed=xxx Mhz option that could be set to define the bus speed. Instead, the SPI bus speed is derived from two separate parameters: the core frequency of the BCM2835 SoC in general (core_freq in /boot/config.txt), and the SPI peripheral CDIV (Clock DIVider) setting. Together, the resulting SPI bus speed is then calculated with the formula SPI_speed=core_freq/CDIV.

Adjust the CDIV value by passing the directive -DSPI_BUS_CLOCK_DIVISOR=number in CMake command line. Possible values are even numbers 2, 4, 6, 8, .... Note that since CDIV appears in the denominator in the formula for SPI_speed, smaller values result in higher bus speeds, whereas higher values make the display go slower. Initially when you don"t know how fast your display can run, try starting with a safe high setting, such as -DSPI_BUS_CLOCK_DIVISOR=30, and work your way to smaller numbers to find the maximum speed the display can cope with. See the table at the end of the README for specific observed maximum bus speeds for different displays.

Ensure turbo speed. This is critical for good frame rates. On the Raspberry Pi 3 Model B, the BCM2835 core runs by default at 400MHz (resulting in 400/CDIV MHz SPI speed) if there is enough power provided to the Pi, and if the CPU temperature does not exceed thermal limits. If the CPU is idle, or voltage is low, the BCM2835 core will instead revert to non-turbo 250MHz state, resulting in 250/CDIV MHz SPI speed. This effect of turbo speed on performance is significant, since 400MHz vs non-turbo 250MHz comes out to +60% of more bandwidth. Getting 60fps in Quake, Sonic or Tyrian often requires this turbo frequency, but e.g. NES and C64 emulated games can often reach 60fps even with the stock 250MHz. If for some reason under-voltage protection is kicking in even when enough power should be fed, you can force-enable turbo when low voltage is present by setting the value avoid_warnings=2 in the file /boot/config.txt.

Perhaps a bit counterintuitively, underclock the core. Setting a smaller core frequency than the default turbo 400MHz can enable using a smaller clock divider to get a higher resulting SPI bus speed. For example, if with default core_freq=400 SPI CDIV=8 works (resulting in SPI bus speed 400MHz/8=50MHz), but CDIV=6 does not (400MHz/6=66.67MHz was too much), you can try lowering core_freq=360 and set CDIV=6 to get an effective SPI bus speed of 360MHz/6=60MHz, a middle ground between the two that might perhaps work. Balancing core_freq= and CDIV options allows one to find the maximum SPI bus speed up to the last few kHz that the display controller can tolerate. One can also try the opposite direction and overclock, but that does then of course have all the issues that come along when overclocking. Underclocking does have the drawback that it makes the Pi run slower overall, so this is certainly a tradeoff.

On the other hand, it is desirable to control how much CPU time fbcp-ili9341 is allowed to use. The default build settings are tuned to maximize the display refresh rate at the expense of power consumption on Pi 3B. On Pi Zero, the opposite is done, i.e. by default the driver optimizes for battery saving instead of maximal display update speed. The following options can be controlled to balance between these two:

The main option to control CPU usage vs performance aspect is the option #define ALL_TASKS_SHOULD_DMA in config.h. Enabling this option will greatly reduce CPU usage. If this option is disabled, SPI bus utilization is maximized but CPU usage can be up to 80%-120%. When this option is enabled, CPU usage is generally up to around 15%-30%. Maximal CPU usage occurs when watching a video, or playing a fast moving game. If nothing is changing on the screen, CPU consumption of the driver should go down very close to 0-5%. By default #define ALL_TASKS_SHOULD_DMA is enabled for Pi Zero, but disabled for Pi 3B.

The CMake option -DUSE_DMA_TRANSFERS=ON should always be enabled for good low CPU usage. If DMA transfers are disabled, the driver will run in Polled SPI mode, which generally utilizes a full dedicated single core of CPU time. If DMA transfers are causing issues, try adjusting the DMA send and receive channels to use for SPI communication with -DDMA_TX_CHANNEL= and -DDMA_RX_CHANNEL= CMake options.

If your SPI display bus is able to run really fast in comparison to the size of the display and the amount of content changing on the screen, you can try enabling #define UPDATE_FRAMES_IN_SINGLE_RECTANGULAR_DIFF option in config.h to reduce CPU usage at the expense of increasing the number of bytes sent over the bus. This has been observed to have a big effect on Pi Zero, so is worth checking out especially there.

If the SPI display bus is able to run really really really fast (or you don"t care about frame rate, but just about low CPU usage), you can try enabling #define UPDATE_FRAMES_WITHOUT_DIFFING option in config.h to forgo the adaptive delta diffing option altogether. This will revert to naive full frame updates for absolutely minimum overall CPU usage.

In display.h there is an option #define TARGET_FRAME_RATE . Setting this to a smaller value, such as 30, will trade refresh rate to reduce CPU consumption.

A pleasing aspect of fbcp-ili9341 is that it introduces very little latency overhead: on a 119Hz refreshing ILI9341 display, fbcp-ili9341 gets pixels as response from GPIO input to screen in well less than 16.66 msecs time. I only have a 120fps recording camera, so can"t easily measure delays shorter than that, but rough statistical estimate of slow motion video footage suggests this delay could be as low as 2-3 msecs, dominated by the ~8.4msecs panel refresh rate of the ILI9341.

This does not mean that overall input to display latency in games would be so immediate. Briefly testing a NES emulated game in Retropie suggests a total latency of about 60-80 msecs. This latency is caused by the NES game emulator overhead and extra latency added by Linux, DispmanX and GPU rendering, and GPU framebuffer snapshotting. (If you ran fbcp-ili9341 as a static library bypassing DispmanX and the GPU stack, directly linking your GPIO input and application logic into fbcp-ili9341, you would be able to get down to this few msecs of overall latency, like shown in the above GPIO input video)

Interestingly, fbcp-ili9341 is about ~33msecs faster than a cheap 3.5" KeDei HDMI display. I do not know if this is a result of the KeDei HDMI display specifically introducing extra latency, or if all HDMI displays connected to the Pi would have similar latency overhead. An interesting question is also how SPI would compare with DPI connected displays on the Pi.

Unfortunately a limitation of SPI connected displays is that the VSYNC line signal is not available on the display controllers when they are running in SPI mode, so it is not possible to do vsync locked updates even if the SPI bus bandwidth on the display was fast enough. For example, the 4 ILI9341 displays I have can all be run faster than 75MHz so SPI bus bandwidth-wise all of them would be able to update a full frame in less than a vsync interval, but it is not possible to synchronize the updates to vsync since the display controllers do not report it. (If you do know of a display that does actually expose a vsync clock signal even in SPI mode, you can try implementing support to locking on to it)

You can however choose between two distinct types of tearing artifacts: straight line tearing and diagonal tearing. Whichever looks better is a bit subjective, which is why both options exist. I prefer the straight line tearing artifact, it seems to be less intrusive than the diagonal tearing one. To toggle this, edit the option #define DISPLAY_FLIP_ORIENTATION_IN_SOFTWARE in config.h. When this option is enabled, fbcp-ili9341 produces straight line tearing, and consumes a tiny few % more CPU power. By default Pi 3B builds with straight line tearing, and Pi Zero with the faster diagonal tearing. Check out the video Latency and tearing test #2: GPIO input to display latency in fbcp-ili9341 and tearing modes to see in slow motion videos how these two tearing modes look like.

Another option that is known to affect how the tearing artifact looks like is the internal panel refresh rate. For ILI9341 displays this refresh rate can be adjusted in ili9341.h, and this can be set to range between ILI9341_FRAMERATE_61_HZ and ILI9341_FRAMERATE_119_HZ (default). Slower refresh rates produce less tearing, but have higher input-to-display latency, whereas higher refresh rates will result in the opposite. Again visually the resulting effect is a bit subjective.

To get tearing free updates, you should use a