The PiTFT requires some device tree support and a couple other things to make it a nice stand-alone display. If you just want to get going, check out the following for easy-install instructions!

Install Raspberry Pi OS on an SD Card

You'll need to start with Raspberry Pi OS or Raspberry Pi OS Lite.

Try the latest version of Raspberry Pi OS first. If that doesn't work. the last known for-sure tested-and-working version is Dec 11, 2023 (https://downloads.raspberrypi.org/raspios_lite_arm64/images/raspios_lite_arm64-2023-12-11/) from https://downloads.raspberrypi.org/raspios_lite_arm64/images/

Raspberry Pi OS does often 'break' stuff when new versions come out so to be safe, if you are having problems try this version!

Setup Virtual Environment

If you are installing on the Bookworm version of Raspberry Pi OS or later, you will need to install your python modules in a virtual environment. You can find more information in the Python Virtual Environment Usage on Raspberry Pi guide. To Install and activate the virtual environment, use the following commands:

sudo apt install python3-venv
python -m venv env --system-site-packages

sudo apt install python3-venv
python -m venv env --system-site-packages

To activate the virtual environment:

source env/bin/activate

source env/bin/activate

Installer script

This script will do all the work for you, and install both device tree overlay support as well as configure rotation and any HDMI mirroring. PiTFT no longer needs any custom kernels or modules, so you can continue to update/upgrade your Pi and it will work with the most recent releases.

Here's the commands to run. Make sure your Pi has network access, it needs to download the software!

The latest installer script was rewritten in Python, so it can be installed with just a few commands. First, start by installing a few dependencies and downloading the repo:

cd ~
sudo apt-get update
sudo apt-get install -y git python3-pip
pip3 install --upgrade adafruit-python-shell click Flask-SQLAlchemy
git clone https://github.com/adafruit/Raspberry-Pi-Installer-Scripts.git
cd Raspberry-Pi-Installer-Scripts

cd ~
sudo apt-get update
sudo apt-get install -y git python3-pip
pip3 install --upgrade adafruit-python-shell click Flask-SQLAlchemy
git clone https://github.com/adafruit/Raspberry-Pi-Installer-Scripts.git
cd Raspberry-Pi-Installer-Scripts

Easy Single Command Install Options

The latest script allows you to specify all of your options within the command so you can sit back and watch the installation. We'll cover interactive installation below if you want to answer each prompt for a customized installation.

“Console Mode” Install Commands

If you just want a Linux text console to appear on the display, use one of the following commands:

For the PiTFT 2.4", 2.8", or 3.2" Resistive touchscreens, use the following command:

sudo -E env PATH=$PATH python3 adafruit-pitft.py --display=28r --rotation=90 --install-type=console

sudo -E env PATH=$PATH python3 adafruit-pitft.py --display=28r --rotation=90 --install-type=console

For the PiTFT 2.8" Capacitive touchscreen, use the following command:

sudo -E env PATH=$PATH python3 adafruit-pitft.py --display=28c --rotation=90 --install-type=console

sudo -E env PATH=$PATH python3 adafruit-pitft.py --display=28c --rotation=90 --install-type=console

For the PiTFT 2.2" Display, use the following command:

sudo -E env PATH=$PATH python3 adafruit-pitft.py --display=22 --rotation=90 --install-type=console

sudo -E env PATH=$PATH python3 adafruit-pitft.py --display=22 --rotation=90 --install-type=console

For the PiTFT 3.5" Resistive touchscreen, use the following command:

sudo -E env PATH=$PATH python3 adafruit-pitft.py --display=35r --rotation=90 --install-type=console

sudo -E env PATH=$PATH python3 adafruit-pitft.py --display=35r --rotation=90 --install-type=console

For the Mini PiTFT 1.3", BrainCraft HAT, 1.3" Color TFT Bonnet, or 1.5" Display, use the following command:

sudo -E env PATH=$PATH python3 adafruit-pitft.py --display=st7789_240x240 --rotation=0 --install-type=console

sudo -E env PATH=$PATH python3 adafruit-pitft.py --display=st7789_240x240 --rotation=0 --install-type=console

For the Mini PiTFT 1.14" Display, use the following command:

sudo -E env PATH=$PATH python3 adafruit-pitft.py --display=st7789_240x135 --rotation=270 --install-type=console

sudo -E env PATH=$PATH python3 adafruit-pitft.py --display=st7789_240x135 --rotation=270 --install-type=console

Mirrored Install Commands

If you want to mirror the HDMI output to the display, known as “FrameBuffer Copy” or FBCP for short, use one of the following commands:

For the PiTFT 2.4", 2.8", or 3.2" Resistive touchscreens, use the following command:

sudo -E env PATH=$PATH python3 adafruit-pitft.py --display=28r --rotation=90 --install-type=mirror

sudo -E env PATH=$PATH python3 adafruit-pitft.py --display=28r --rotation=90 --install-type=mirror

For the PiTFT 2.8" Capacitive touchscreen, use the following command:

sudo -E env PATH=$PATH python3 adafruit-pitft.py --display=28c --rotation=90 --install-type=mirror

sudo -E env PATH=$PATH python3 adafruit-pitft.py --display=28c --rotation=90 --install-type=mirror

For the PiTFT 2.2" Display, use the following command:

sudo -E env PATH=$PATH python3 adafruit-pitft.py --display=22 --rotation=90 --install-type=mirror

sudo -E env PATH=$PATH python3 adafruit-pitft.py --display=22 --rotation=90 --install-type=mirror

For the PiTFT 3.5" Resistive touchscreen, use the following command:

sudo -E env PATH=$PATH python3 adafruit-pitft.py --display=35r --rotation=90 --install-type=mirror

sudo -E env PATH=$PATH python3 adafruit-pitft.py --display=35r --rotation=90 --install-type=mirror

For the Mini PiTFT 1.3", BrainCraft HAT, 1.3" Color TFT Bonnet, or 1.5" Display, use the following command:

sudo -E env PATH=$PATH python3 adafruit-pitft.py --display=st7789_240x240 --rotation=0 --install-type=mirror

sudo -E env PATH=$PATH python3 adafruit-pitft.py --display=st7789_240x240 --rotation=0 --install-type=mirror

For the Mini PiTFT 1.14" Display, use the following command:

sudo -E env PATH=$PATH python3 adafruit-pitft.py --display=st7789_240x135 --rotation=270 --install-type=mirror

sudo -E env PATH=$PATH python3 adafruit-pitft.py --display=st7789_240x135 --rotation=270 --install-type=mirror

Rebooting

When it asks you to reboot, then choose yes because the setting won't take full effect until you do so.

Interactive Installation

For an interactive install, you can just run the script without any options:

sudo -E env PATH=$PATH python3 adafruit-pitft.py

Once you run it you will be presented with menus for configuration.

Display Selection

Start by selecting the board that best corresponds with your PiTFT. There's lots of options and we will likely be adding more in the future.

Rotation

Next you will be asked for the rotation you want, don't worry if you're not 100% sure which you want, you can always change this later by re-running the script

It will take a few minutes to install the software and download all the things...

Configuring what shows where

You have a few different ways to set up the PiTFT, we ask 2 questions to figure out what you want

PiTFT as Text Console (best for Raspberry Pi OS 'Lite')

This is the simplest to set-up type of use. Its great if you have a simple text based or pygame/SDL based interface. If you want the PiTFT to act as a text console you can expect:

• HDMI will be 'deactivated' - nothing appears on the HDMI output but a black screen
• The login prompt appears on the Pi
• The Pi is all text, not a GUI (no PIXEL desktop)
• Keyboard and mouse are used only by the PiTFT interface
• Framebuffer-capable software (such as fbi for displaying images, mplayer for videos, or pygame software, etc) appear on the PiTFT
• OpenGL accelerated software will not appear on the PiTFT (it is unaccelerated framebuffer only)
• But, non-OpenGL-accelerated graphics software is a bit faster than using HDMI mirroring (not tons faster but you're not running fbcp which will always make it faster)

If you want that, say Yes to the question Would you like the console to appear on the PiTFT display

Then simply reboot. Once rebooted you will not see anything on HDMI, but the console will appear on the PiTFT. That's it!

PiTFT as HDMI Mirror (Best for Raspberry Pi OS with Desktop)

This option is easier to understand. This works more like a monitor, though slightly different depending on which desktop environment you are running.

As of Bookworm with the Wayland Graphical Environment, this operates a little different than it previously did. It works more in the way that multiple monitors do on desktop systems. The display is set up as its own monitor and will extend the desktop in addition to the HDMI.

With X11, this worked more as a mirror: whatever appears on the HDMI display will be 'mirrored' to the PiTFT. Note that HDMI is much higher resolution so it's not like it turns the PiTFT into a 1080p display. This is great for when you want to run OpenGL-optimized software, PIXEL desktop software, or really anything. The down-side is its a little slower than drawing directly to the framebuffer. You may not notice it but it's worth us mentioning!

• HDMI will be 'activated' but at a lower resolution - you can change this later but it looks best at 320x240 (PiTFT 2.2", 2.4", 2.8" and 3.2") or 480x320 (PiTFT 3.5")
• The login prompt or GUI appears on both HDMI and PiTFT at the same time
• Keyboard and mouse are shared, since the display is mirrored
• All graphics appear on both HDMI and PiTFT, thanks to fbcp

If you want that, say Yes to the question Would you like the HDMI display to mirror to the PiTFT display?(or in the case of Wayland it will ask Would you like the to use the PiTFT as a desktop display?)

PiTFT as Raw Framebuffer Device

For advanced users who are comfortable using framebuffer devices, it is possible to have the PiTFT and HDMI graphics be both active and display different data.

• HDMI will be active and act like a normal Pi
• The login prompt or GUI (PIXEL) appears on the HDMI
• PiTFT appears black, nothing appears on it
• Keyboard and mouse are used by the HDMI interface but can, in theory, be captured and used to change graphics on PiTFT through programming
• Framebuffer-capable software (such as fbi for displaying images, mplayer for videos, or pygame software, etc) can appear on the PiTFT if you set it up to display to /dev/fb1
• OpenGL accelerated software will never appear on the PiTFT (it is unaccelerated framebuffer only)

If you want that, say No to both of the configuration questions!

Creating Your Own Automated Command

Under the Easy Single Command Install Options section, there are a bunch of different installation flags that you can choose between. If you want to create your own command, you can find the latest options by typing:

sudo python3 adafruit-pitft.py --help

The main options to pay attention to are the --display, --rotation, and --install-type arguments.

For the display, you can either choose the number you type for the options or the display type, which has the options listed under help. For instance, to us the 2.8" Resisitive display you could use

--display=1 or --display=28r

For the rotation, you can either choose the number you type for the options or the angle, which has the options also listed under help. To use 90 degrees, you could use

--rotation=1 or --rotation=90

For install type, You can either choose mirror, console or uninstall. To mirror, you would simply supply

--install-type=mirror

Automated Reboot Option

To go with a fully automated installation, you can provide a --reboot flag. To always reboot, use:

--reboot=yes

This is useful if you want to use the display right after running the script. To never reboot immediately, use

--reboot=no

This is useful if you want it as part of a larger script that installs many things.

Custom User Directory

By default, it is installed under the current user directory, but you can provide the -u or --user flag along with the folder that you want to install to.

Uninstalling The Driver

To uninstall, you would either run the script interactively and choose Uninstall or you can provide the uninstall flag:

--install-type=uninstall

Unsupported Full Images

Historically, we provided full 'images' of Raspbian, which is now called Raspberry Pi OS. This worked OK until Raspbian started doing releases every few months. These are no longer supported, and won't even boot on Pi 3B+, so we recommend the script above.

There's the larger 'classic Jessie' image that will boot into X by default, and requires a 8G image, it has a lot more software installed. There's also the smaller 'Jessie Lite' that will boot into the command line, and can be burned onto a 2G card! Click below to download and install into a new SD card. Unzip and follow the classic SD card burning tutorials

PiTFT 2.2" Images

• Raspbian Jessie 2016/10/23-based image
• Raspbian Jessie Lite 2016/10/23-based image
• Raspbian Jessie 2016/03/25-based image
• Raspbian Jessie Lite 2016/03/25-based image
• Raspbian Jessie 2015/09/24-based image
• Raspbian Wheezy 2015/09/09-based image

PiTFT 2.4"/2.8"/3.2" Resistive Images

• Raspbian Jessie 2016/9/23-based image
• Raspbian Jessie Lite 2016/9/23-based image
• Raspbian Jessie 2016/03/25-based image
• Raspbian Jessie Lite 2016/03/25-based image
• Raspbian Jessie 2015/09/24-based image
• Raspbian Wheezy 2015/09/09-based image
• Raspbian 2014/06/20-based image
• Raspbian 2014/09/09-based image

PiTFT 2.8" Capacitive

• Raspbian Jessie 2016-09-23-based image
• Raspbian Jessie Lite 2016-09-23-based image
• Raspbian Jessie 2016-03-25-based image
• Raspbian Jessie Lite 2016-03-25-based image
• Raspbian Jessie 2015/09/24-based image
• Raspbian Wheezy 2015/09/24-based image
• Raspbian 2014/09/18-based image
• Raspbian 2014/06/20-based image
• Raspbian image from 2015/03/03

PiTFT 3.5" Images

• Raspbian Jessie 2016/9/23-based image
• Raspbian Jessie Lite 2016/9/23-based image
• Raspbian Jessie 2016/03/25-based image
• Raspbian Jessie 2016/03/25-based image
• Raspbian Jessie 2015/09/24-based image
• Raspbian Wheezy 2015/09/24-based image
• Raspbian 2014/09/09-based image
• Raspbian 2015/03/12 image

Setting up the Touchscreen

Now that the screen is working nicely, we'll take care of the touchscreen. There's just a bit of calibration to do, but it isn't hard at all.

Before we start, we'll make a udev rule for the touchscreen. That's because the eventX name of the device will change a lot and its annoying to figure out what its called depending on whether you have a keyboard or other mouse installed.

Run

sudo nano /etc/udev/rules.d/95-stmpe.rules

to create a new udev file and copy & paste the following line in:

SUBSYSTEM=="input", ATTRS{name}=="stmpe-ts", ENV{DEVNAME}=="*event*", SYMLINK+="input/touchscreen" 

SUBSYSTEM=="input", ATTRS{name}=="stmpe-ts", ENV{DEVNAME}=="*event*", SYMLINK+="input/touchscreen" 

Remove and re-install the touchscreen with

sudo rmmod stmpe_ts; sudo modprobe stmpe_ts

Then type ls -l /dev/input/touchscreen
It should point to eventX where X is some number, that number will be different on different setups since other keyboards/mice/USB devices will take up an event slot

There are some tools we can use to calibrate & debug the touchscreen. Install the "event test" and "touchscreen library" packages with

sudo apt-get install evtest tslib libts-bin

Running evtest

Now you can use some tools such as

sudo evtest /dev/input/touchscreen

which will let you see touchscreen events in real time, press on the touchscreen to see the reports.

AutoMagic Calibration Script

If you rotate the display you need to recalibrate the touchscreen to work with the new screen orientation. You can manually run the calibration processes in the next section, or you can re-run the installer script and select a new rotation:

Try using this default calibration script to easily calibrate your touchscreen display. Note that the calibration values might not be exactly right for your display, but they should be close enough for most needs. If you need the most accurate touchscreen calibration, follow the steps in the next section to manually calibrate the touchscreen.

Manual Calibration

If the "automagic" calibration technique isn't working for you, or you have some other setup where you need to carefully calibrate you can do it 'manually'

You will want to calibrate the screen once but shouldn't have to do it more than that. We'll begin by calibrating on the command line by running

sudo TSLIB_FBDEVICE=/dev/fb1 TSLIB_TSDEVICE=/dev/input/touchscreen ts_calibrate

follow the directions on the screen, touching each point. Using a stylus is suggested so you get a precise touch. Don't use something metal, plastic only!

Next you can run

sudo TSLIB_FBDEVICE=/dev/fb1 TSLIB_TSDEVICE=/dev/input/touchscreen ts_test

which will let you draw-test the touch screen. Go back and re-calibrate if you feel the screen isn't precise enough!

X Calibration

You can also calibrate the X input system but you have to use a different program called xtcal (xinput_calibrator no longer works)

You can do this if the calibration on the screen isn't to your liking or any time you change the rotate=XX module settings for the screen. Since the screen and touch driver are completely separated, the touchscreen doesn't auto-rotate

Download and compile it with the following:

sudo apt-get install libxaw7-dev libxxf86vm-dev libxaw7-dev libxft-dev
git clone https://github.com/KurtJacobson/xtcal
cd xtcal
make

sudo apt-get install libxaw7-dev libxxf86vm-dev libxaw7-dev libxft-dev
git clone https://github.com/KurtJacobson/xtcal
cd xtcal
make

You must be running PIXEL (the GUI) while calibrating.

Before you start the calibrator you will need to 'reset' the old calibration data so run

DISPLAY=:0.0 xinput set-prop "stmpe-ts" 'Coordinate Transformation Matrix' 1 0 0 0 1 0 0 0 1

Now you'll have to run the calibrator while also running X. You can do this by opening up the terminal program and running the the xtcal command (which is challenging to do on such a small screen) OR you can do what we do which is create an SSH/Terminal shell and then run the calibrator from the same shell, which requires the following command:

DISPLAY=:0.0 xtcal/xtcal -geometry 640x480

Note that the geometry may vary!

If you are using a 2.4"/2.8"/3.2" 320x240 display with landscape orientation, use 640x480. If you're in portrait, use 480x640.

If you are using a 3.5" display with landscape, use 720x480, portrait is 480x720

Follow the directions on screen

Once complete you'll get something like:

Run sudo nano /usr/share/X11/xorg.conf.d/20-calibration.conf and copy the 9 numbers into the TransformationMatrix option so it looks like:

Section "InputClass"
        Identifier "STMPE Touchscreen Calibration"
        MatchProduct "stmpe"
        MatchDevicePath "/dev/input/event*"
        Driver "libinput"
        Option "TransformationMatrix" "-0.000087 1.094214 -0.028826 -1.091711 -0.004364 1.057821 0 0 1"
EndSection

Section "InputClass"
        Identifier "STMPE Touchscreen Calibration"
        MatchProduct "stmpe"
        MatchDevicePath "/dev/input/event*"
        Driver "libinput"
        Option "TransformationMatrix" "-0.000087 1.094214 -0.028826 -1.091711 -0.004364 1.057821 0 0 1"
EndSection

or whatever you got, into there.

You will want to reboot your Pi to verify you're done

Your touchscreen is now super calibrated, hurrah!

One fun thing you can do with the display is have it as your main console instead of the HDMI/TV output. Even though it is small, with a good font you can get 20 x 40 of text. For more details, check out https://github.com/notro/fbtft/wiki/Boot-console

First up, we'll update the boot configuration file to use the TFT framebuffer /dev/fb1 instead of the HDMI/TV framebuffer /dev/fb0

sudo nano /boot/cmdline.txt

you can also edit it by putting the SD card into a computer and opening the same file.

At the end of the line, find the text that says rootwait and right after that, enter in:
fbcon=map:10 fbcon=font:VGA8x8 then save the file.

On the next boot, it will bring up the console.

Note that the kernel has to load up the display driver module before it can display anything on it so you won't get the rainbow screen, a NooBs prompt, or a big chunk of the kernel details since the module is loaded fairly late in the boot process.

I think the VGA8x8 font is a bit chunky, you probably want 12x6 which is what is shown in the photo above. To change the font, run sudo dpkg-reconfigure console-setup and go thru to select Terminus 6x12

Turn off Console Blanking

You may notice the console goes black after 30 minutes, this is a sort of 'power saving' or 'screensaver' feature.

Raspbian Jessie

 Add the following line to /etc/rc.local

sudo sh -c "TERM=linux setterm -blank 0 >/dev/tty0"

on the line before the final exit 0

Raspbian Wheezy

You can disable this by editing /etc/kbd/config and looking for 

BLANK_TIME=30

and setting the blank time to 0 (which turns it off)

BLANK_TIME=0

You can display every day images such as GIFs, JPGs, BMPs, etc on the screen. To do this we'll install fbi which is the frame buffer image viewer (not to be confused with the FBI agency!)

sudo apt-get install fbi will install it

Grab our lovely wallpapers with

wget http://adafruit-download.s3.amazonaws.com/adapiluv320x240.jpg
wget http://adafruit-download.s3.amazonaws.com/adapiluv480x320.png

For 320x240 PiTFTs (2.2", 2.4", 2.8" or 3.2") view it with

sudo fbi -T 2 -d /dev/fb1 -noverbose -a adapiluv320x240.jpg

or for 3.5" PiTFTs:

sudo fbi -T 2 -d /dev/fb1 -noverbose -a adapiluv480x320.png

That's it!

How To Play Videos

You can play many types of videos on the screen, using mplayer you don't even need to run X and you can script the movies to play using Python. We'll show you how to just play one video for now.
To demo, we'll use an mp4 of Big Buck Bunny for 320 pixel wide screens. Below we show you how to create/resize videos, but to make it easy, just download our version with:

wget http://adafruit-download.s3.amazonaws.com/bigbuckbunny320p.mp4

If you don't have mplayer yet, run

sudo apt-get update

sudo apt-get install mplayer

to install it. It may take a few minutes to complete

OK now you just have to run:

sudo SDL_VIDEODRIVER=fbcon SDL_FBDEV=/dev/fb1 mplayer -vo sdl -framedrop bigbuckbunny320p.mp4

If your video is not sized for 320 wide, you may need to add a -zoom after -framedrop so that it will resize - note that this is quite taxing for the Pi, so it may result in a choppy or mis-synced video!

Converting/Resizing Videos

It's possible to play full length videos on the TFT plate, but since the screen is small and the Pi cant use hardware accelleration to play the videos its best to scale them down to 320x240 pixels. This will be easier for the Pi to play and also save you tons of storage space. For this demo, we'll be using the famous Big Buck Bunny video, which is creative commons and also very funny!

You can download it from the link above, we'll be using the 720p AVI version.

To do the conversion itself, we suggest HandBrake which works great and is open source so it runs on all operating systems! Download and install from the link. Then run the installed application and open up the AVI file from before. The app will pre-fill a bunch of information about it.

Under Destination click Browse... to select a new MP4 file to save. Then under Picture change the Width to 320 (the height will be auto-calculated)

Click START to begin the conversion, it will take a minute or two.

That's it! You now have a smaller file. Don't forget to play it on your computer to make sure it plays right before copying it to your Pi

The Ideal: Adafruit’s PiTFT displays are razor sharp. Whereas small composite screens on the Raspberry Pi usually require some video scaling (resulting in blurriness), PiTFT uses the GPIO header, digitally controlled pixel-by-pixel for a rock steady image. Though not a lot of pixels, it works great for retro gaming (and the display neatly stacks above the board, no side protuberances for video cables).

The Downside: this GPIO link entirely bypasses the Pi’s video hardware, including the graphics accelerator. Many games and emulators depend on the GPU for performance gains. So the PiTFT has traditionally been limited to just a subset of specially-compiled emulators that can work and run well enough without the GPU.

The Solution: our latest PiTFT drivers, along with a tool called fbcp (framebuffer copy), careful system configuration, and (optionally) the more potent Raspberry Pi 2 board open the doors to many more gaming options. Existing emulator packages (such as RetroPie, with dozens of high-performance emulators and ports) — previously off-limits to the PiTFT — can run quite effectively now!

The backlight of the 2.8" PiTFT has 4 LEDs in series and it draws ~75mA at all times, controlled by a transistor. The PiTFT 3.5" display has 6 LEDs in a row, and we use a boost converter to get the 5V from the Pi up to the ~20V needed to light up all the LEDs.

There might be times you'd like to save some power and turn off the backlight. The screen and touchplate will still work, you just can't see anything. We designed the board with the STMPE610 touchscreen controller which has 2 extra GPIO and tied one of them to control the backlight. You can use the command line to control the backlight.

By default, the backlight's on...but you can control it in two ways!

PWM Backlight Control with GPIO 18

If you want precise control, you can use the PWM output on GPIO 18. There's python code for controlling the PWM but you can also just use the kernel module and shell commands.

You'll need to make sure the STMPE control is not 'active' as the STMPE GPIO overrides the PWM output.

sudo sh -c 'echo "0" > /sys/class/backlight/soc\:backlight/brightness'

(Or if you are running an old kernel before the backlight object, try sudo sh -c "echo 'in' > /sys/class/gpio/gpio508/direction")

OK now you can set the GPIO #18 pin to PWM mode using WiringPi's gpio command

With these basic shell commands, you can set the GPIO #18 pin to PWM mode with 1000 Hz frequency, set the output to 100 (out of 1023, so dim!), set the output to 1023 (out of 1023, nearly all the way on) and 0 (off)

gpio -g mode 18 pwm
gpio pwmc 1000
gpio -g pwm 18 100
gpio -g pwm 18 1023
gpio -g pwm 18 0

gpio -g mode 18 pwm
gpio pwmc 1000
gpio -g pwm 18 100
gpio -g pwm 18 1023
gpio -g pwm 18 0

Disabling Backlight Control

On / Off Using STMPE GPIO

Another option is to just turn it on and off using the extra GPIO created by the touchscreen driver

Thanks to the raspberry Pi overlay system, this GPIO is already set up for you in a file called /sys/class/backlight/soc:backlight/brightness

To turn the backlight off run

sudo sh -c 'echo "0" > /sys/class/backlight/soc\:backlight/brightness'

To turn it back on, run

sudo sh -c 'echo "1" > /sys/class/backlight/soc\:backlight/brightness'

On / Off Using GPIO for the Capacitive Display

If you installed the capacitive display, you may notice that /sys/class/backlight isn't available. This is because the capacitive display uses a different touchscreen driver than the STMPE. You can however still control it using GPIO 18. Start by getting access to the GPIO by making a device link:

echo 18 >/sys/class/gpio/export

Check that the gpio18 was created:

ls /sys/class/gpio/

Set the direction to out with:

echo out >/sys/class/gpio/gpio18/direction

The backlight should turn off. You can turn it on with:

echo 1 >/sys/class/gpio/gpio18/value

or back off again with

echo 0 >/sys/class/gpio/gpio18/value

For older versions of PiTFT Kernel

On older versions of the PiTFT kernel/overlay, the GPIO was not tied to the backlight device. Start by getting access to the GPIO by making a device link

sudo sh -c "echo 508 > /sys/class/gpio/export"
ls -l /sys/class/gpio

For some really old versions, the GPIO pin was #252 not #508 so substitute that if you're running something from 2014 or earlier

Once you verify that you see GPIO #508, then you can set it to an output, this will turn off the display since it will output 0 by default

sudo sh -c "echo 'out' > /sys/class/gpio/gpio508/direction"

Then turn the display back on with

sudo sh -c "echo '1' > /sys/class/gpio/gpio508/value"

or back off

sudo sh -c "echo '0' > /sys/class/gpio/gpio508/value"

Python Backlight Control with Blinka

You can also control the backlight using Python. With Blinka, you can use it to turn the backlight off or on or even use PWM to control the level of the backlight. Since Python is such a flexible language, you can add some effects such as fading the backlight in or fading it out. First make sure you have Blinka installed. For the Raspberry Pi, you can follow our CircuitPython Libraries on Linux and Raspberry Pi guide. To turn the backlight on, you can use this simple demo script:

import board
import digitalio
backlight = digitalio.DigitalInOut(board.D18)
backlight.switch_to_output()
backlight.value = True

import board
import digitalio
backlight = digitalio.DigitalInOut(board.D18)
backlight.switch_to_output()
backlight.value = True

To turn it off, you can use this script:

import board
import digitalio
backlight = digitalio.DigitalInOut(board.D18)
backlight.switch_to_output()
backlight.value = False

import board
import digitalio
backlight = digitalio.DigitalInOut(board.D18)
backlight.switch_to_output()
backlight.value = False

To use PWM and demonstrate the fading in and fading out effect, you can try running this script:

import time
import board
import pwmio

led = pwmio.PWMOut(board.D18, frequency=5000, duty_cycle=0)

while True:
    for i in range(101):
        led.duty_cycle = int(i * 65535 / 100)  # Up
        time.sleep(0.01)
    time.sleep(1)
    for i in range(100, -1, -1):
        led.duty_cycle = int(i * 65535 / 100)  # Down
        time.sleep(0.01)
    time.sleep(1)

import time
import board
import pwmio

led = pwmio.PWMOut(board.D18, frequency=5000, duty_cycle=0)

while True:
    for i in range(101):
        led.duty_cycle = int(i * 65535 / 100)  # Up
        time.sleep(0.01)
    time.sleep(1)
    for i in range(100, -1, -1):
        led.duty_cycle = int(i * 65535 / 100)  # Down
        time.sleep(0.01)
    time.sleep(1)

With the PiTFT touchscreen and xstroke you can enter text in applications by drawing simple character gestures on the screen! Check out the video below for a short demonstration and overview of gesture input with xstroke:

Installation

Unfortunately xstroke hasn't been actively maintained for a few years so there isn't a binary package you can directly install. However compiling the tool is straightforward and easy with the steps below. Credit for these installation steps goes to mwilliams03 at ozzmaker.com.

First install a few dependencies by opening a command window on the Pi and executing:

sudo apt-get -y install build-essential libxft-dev libxpm-dev libxtst-dev

sudo apt-get -y install build-essential libxft-dev libxpm-dev libxtst-dev

Now download, compile, and install xstroke by executing:

cd ~
wget http://mirror.egtvedt.no/avr32linux.org/twiki/pub/Main/XStroke/xstroke-0.6.tar.gz
tar xfv xstroke-0.6.tar.gz
cd xstroke-0.6
./configure
sed -i '/^X_LIBS = / s/$/ -lXrender -lX11 -lXext -ldl/' Makefile
make
sudo make install

cd ~
wget http://mirror.egtvedt.no/avr32linux.org/twiki/pub/Main/XStroke/xstroke-0.6.tar.gz
tar xfv xstroke-0.6.tar.gz
cd xstroke-0.6
./configure
sed -i '/^X_LIBS = / s/$/ -lXrender -lX11 -lXext -ldl/' Makefile
make
sudo make install

If the commands above execute successfully xstroke should be installed. If you see an error message, carefully check the dependencies above were installed and try again.

Once xstroke is installed you will want to add a couple menu shortcuts to start and stop xstroke. Execute the following commands to install these shortcuts:

wget https://github.com/adafruit/PiTFT_Extras/raw/master/xstroke.desktop
wget https://github.com/adafruit/PiTFT_Extras/raw/master/xstrokekill.desktop
sudo cp xstroke*.desktop /usr/share/applications/

wget https://github.com/adafruit/PiTFT_Extras/raw/master/xstroke.desktop
wget https://github.com/adafruit/PiTFT_Extras/raw/master/xstrokekill.desktop
sudo cp xstroke*.desktop /usr/share/applications/

Usage

To use xstroke I highly recommend using a plastic stylus instead of your finger. Also calibrate the touchscreen for X-Windows so you have the best control over the cursor possible.

Start X-Windows on the PiTFT and open the LXDE menu by clicking the icon in the lower left corner. Scroll up to the Accessories menu at the top and notice the new XStroke and XStroke Kill commands.

Click the XStroke menu option to start xstroke. You should see a small pencil icon appear on the bottom right side of the screen. The pencil icon means xstroke is running, however by default it's not yet looking for gesture input.

Open an application that takes text input, such as LXTerminal. To enable gesture input click the xstroke pencil icon. You should see the pencil turn green and the text 'abc' written over top of the icon. You might need to click the icon a few times to get the click to register in the right spot.

When xstroke is looking for gesture input you can drag the mouse cursor in a gesture anywhere on the screen to send specific key strokes. Here's a picture of the possible gestures you can send:

(credit to Carl Worth for the image above)

To draw a gesture from the above image, press anywhere on the screen, start from the circle in the gesture, and follow the gesture pattern towards the arrow. As you draw a gesture you should see a blue line displayed that shows what you've drawn. Lift up the stylus when you get to the end of the gesture at the arrow. If xstroke recognizes the gesture it will send the appropriate key press to the active window. Try drawing a few characters from the image above to get the hang of writing gestures.

A few very useful gestures are backspace (which deletes a character), return/enter, and space. To draw a backspace gesture just draw a line going from the right side of the screen to the left side. The gesture for return/enter is a diagonal line from the top right to bottom left. Finally a space is a straight line from the left to the right.

Note that when xstroke is looking for gestures you might not be able to click or control the cursor as you normally would expect. To stop xstroke's gesture recognition carefully press the xstroke pencil icon again until the 'abc' text disappears. I've found this process can be a little finicky as the icon is very small and any movement will be interpreted as a gesture. Use a light touch and try a few times to click the icon.

If you get stuck completely and can't disable xstroke by clicking the icon, connect to the Raspberry Pi in a terminal/SSH connection and run 'killall xstroke' (without quotes) to force xstroke to quit. The normal way to stop xstroke is to navigate to the Accessories -> XStroke Kill command, but you might not be able to do that if xstroke is listening for gesture input.

Have fun using xstroke to control your Pi by writing gestures on the PiTFT screen!

Since the PiTFT screen is fairly small, you may need to write custom UI programs. Pygame is the easiest way by far to do this.

Jeremy Blythe has an excellent tutorial here on getting started. 

However, before you follow that link you'll want to set up pygame for the best compatibility:

Install pip & pygame

Install Pip: sudo apt-get install python3-pip

Install Pygame: sudo apt-get install python3-pygame

(this will take a while)

Running SDL 1.2

If you experience issues with the current version of SDL, you can try running an older version. 

Some versions of SDL 2.x and SDL 1.2.15-10 have some serious incompatibilities with touchscreen. You can force SDL 1.2 by running a script. (Thanks to heine in the forums!)

Edit a new file with sudo nano installsdl.sh
and paste in the following text:

#!/bin/bash

# enable wheezy package sources
echo "deb http://legacy.raspbian.org/raspbian wheezy main
" > /etc/apt/sources.list.d/wheezy.list

# set stable as default package source (currently buster)
echo "APT::Default-release \"stable\";
" > /etc/apt/apt.conf.d/10defaultRelease

# set the priority for libsdl from wheezy higher then the buster package
echo "Package: libsdl1.2debian
Pin: release n=buster
Pin-Priority: -10
Package: libsdl1.2debian
Pin: release n=wheezy
Pin-Priority: 900
" > /etc/apt/preferences.d/libsdl

# install
apt-get update
apt-get -y --allow-downgrades install libsdl1.2debian/wheezy

#!/bin/bash

# enable wheezy package sources
echo "deb http://legacy.raspbian.org/raspbian wheezy main
" > /etc/apt/sources.list.d/wheezy.list

# set stable as default package source (currently buster)
echo "APT::Default-release \"stable\";
" > /etc/apt/apt.conf.d/10defaultRelease

# set the priority for libsdl from wheezy higher then the buster package
echo "Package: libsdl1.2debian
Pin: release n=buster
Pin-Priority: -10
Package: libsdl1.2debian
Pin: release n=wheezy
Pin-Priority: 900
" > /etc/apt/preferences.d/libsdl

# install
apt-get update
apt-get -y --allow-downgrades install libsdl1.2debian/wheezy

run

sudo sh ./installsdl.sh

it will force install SDL 1.2

OK now you can continue with pygame

Using the Capacitive touch screen in PyGame

The 2.8" Capacitive touch screen driver may not work by default in pygame, but this handy script shows how you can capture the device messages in python to create a UI

• https://github.com/nift4/pigame
  For examples:
  https://github.com/nift4/Raspberry-Pi-Testing