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adafrult learning system

Adafruit PiTFT 3.5" Touch Screen for Raspberry Pi

Created by lady ada

Last updated on 2019-06-14 08:25:20 PM UTC

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Overview

Is this not the cutest, little display for the Raspberry Pi? It features a 3.5" display with 480x320 16-bit color pixels and a

resistive touch overlay, but is only slightly larger than our popular original (https://adafru.it/dDE). The plate uses the

high speed SPI interface on the Pi and can use the mini display as a console, X window port, displaying images or

video etc. Best of all it plugs right in on top!

It's designed to fit nicely onto the Pi Model A or B but also works perfectly fine with the Model B+ as long as you don't

mind the PCB overhangs the USB ports by 5mm.

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Uses the hardware SPI pins (SCK, MOSI, MISO, CE0, CE1) as well as GPIO #25 and #24. GPIO #18 can be used to PWM

dim the backlight if you like. All other GPIO are unused. There's a 2x13 header on the bottom, you can connect a

standard Pi GPIO cable to it to use any of the other pins ask you like

Best of all, it comes fully assembled and ready to plug into your Pi! You can use this as a display for running the X

interface, or pygame. You can also have an HDMI display seperately connected.

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Easy Install

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 Raspbian on an SD Card

You'll need to start with Raspbian or Raspbian Lite.

The last known for-sure tested-and-working version is March 13, 2018

(https://downloads.raspberrypi.org/raspbian/images/raspbian-2018-03-14/ (https://adafru.it/F2M)) from

https://downloads.raspberrypi.org/raspbian/images/ (https://adafru.it/BFU)

Raspbian does often 'break' stuff when new versions come out so to be safe, if you are having problems try this

version!

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 same installer is used for all PiTFTs, you will pick and configure the setup during installation!



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PiTFT Selection

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

For the 2.4", 2.8" and 3.2" PiTFT with resistive

touchscreen overlay select #1

cd ~

wget https://raw.githubusercontent.com/adafruit/Raspberry-Pi-Installer-Scripts/master/adafruit-pitft.sh

chmod +x adafruit-pitft.sh

sudo ./adafruit-pitft.sh

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For the 2.2" PiTFT select #2

For the 2.8" Capacitive PiTFT select #3

For the 3.5" PiTFT select #4

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

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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 Raspbian '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

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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 Raspbian Full/PIXEL)

This option is the easiest to understand: 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?

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!

Unsupported Full Images

Historically, we provided full 'images' of Raspbian. This worked OK until Raspbian started doing releases every few

You can always change your mind after setting up one of the configurations, depending on your needs! Just

re-run the script



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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
 (https://adafru.it/aMW)
PiTFT 2.2" Images
Raspbian Jessie 2016/10/23-based image (https://adafru.it/sbg)
Raspbian Jessie Lite 2016/10/23-based image (https://adafru.it/sbh)
Raspbian Jessie 2016/03/25-based image (https://adafru.it/mAe)
Raspbian Jessie Lite 2016/03/25-based image (https://adafru.it/mAf)
Raspbian Jessie 2015/09/24-based image (https://adafru.it/iDC)
Raspbian Wheezy 2015/09/09-based image (https://adafru.it/idt)
PiTFT 2.4"/2.8"/3.2" Resistive Images
Raspbian Jessie 2016/9/23-based image (https://adafru.it/s7f)
Raspbian Jessie Lite 2016/9/23-based image (https://adafru.it/s7A)
Raspbian Jessie 2016/03/25-based image (https://adafru.it/mA9)
Raspbian Jessie Lite 2016/03/25-based image (https://adafru.it/mAa)
Raspbian Jessie 2015/09/24-based image (https://adafru.it/iDA)
Raspbian Wheezy 2015/09/09-based image (https://adafru.it/idJ)
Raspbian 2014/06/20-based image (https://adafru.it/dSM)
Raspbian 2014/09/09-based image (https://adafru.it/e12)
PiTFT 2.8" Capacitive
Raspbian Jessie 2016-09-23-based image (https://adafru.it/saM)
Raspbian Jessie Lite 2016-09-23-based image (https://adafru.it/saN)
Raspbian Jessie 2016-03-25-based image (https://adafru.it/mAc)
Raspbian Jessie Lite 2016-03-25-based image (https://adafru.it/mAd)
Raspbian Jessie 2015/09/24-based image (https://adafru.it/iDy)
Raspbian Wheezy 2015/09/24-based image (https://adafru.it/idz)
Raspbian 2014/09/18-based image (https://adafru.it/e11)
Raspbian 2014/06/20-based image (https://adafru.it/dSO)
Raspbian image from 2015/03/03 (https://adafru.it/eUI)
PiTFT 3.5" Images
Raspbian Jessie 2016/9/23-based image (https://adafru.it/siF)
Raspbian Jessie Lite 2016/9/23-based image (https://adafru.it/sja)
Raspbian Jessie 2016/03/25-based image (https://adafru.it/mAb)
Raspbian Jessie 2016/03/25-based image (https://adafru.it/mAG)
Raspbian Jessie 2015/09/24-based image (https://adafru.it/iDD)
Raspbian Wheezy 2015/09/24-based image (https://adafru.it/idy)
Raspbian 2014/09/09-based image (https://adafru.it/e10)
Raspbian 2015/03/12 image (https://adafru.it/eUE)
© Adafruit Industries https://learn.adafruit.com/adafruit-pitft-3-dot-5-touch-screen-for-raspberry-
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Resistive Touchscreen Manual Install &

Calibrate

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:

If you've grabbed our Easy Install image, or used the installer script, this step is not required, it's already

done! This is just for advanced users who are curious on how to configure and customize the touchscreen



This procedure is identical for the 2.4", 2.8", 3.2" and 3.5" Resistive PiTFTs. Not for use with the Capacitive

PiTFT!



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

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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

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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.

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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!

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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 should see five crosshair targets. If you see less than that, the touchscreen probably generated multiple

signals for a single touch, and you should try calibrating again.



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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:

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:

sudo apt-get install libxaw7-dev libxxf86vm-dev libxaw7-dev libxft-dev

git clone https://github.com/KurtJacobson/xtcal

cd xtcal

make

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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:

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!

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

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Console Configuration

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 (https://adafru.it/cXQ)

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

If you've used our installer script, this step is not required, it's already done! This is just for advanced users

who are curious on how to configure and customize the console



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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

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

BLANK_TIME=0

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* adafrult learning system

Displaying Images

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 (https://adafru.it/cXU)

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 (https://adafru.it/cXU).png

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That's it!

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* adafrult learning system

Playing

Videos

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 (https://adafru.it/cXR)

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

The video is 30MB which is a lot if you haven't expanded your SD card yet. Before you do this, run sudo

raspi-config to expand the SD card so you don't run out of space!



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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 (https://adafru.it/cXS)

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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 (https://adafru.it/cXT) 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)

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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

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* adafrull learning system

Using FBCP

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!

https://adafru.it/fbe

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Backlight Control

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 "1" > /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)

If you'd like to not have #18 control the backlight, simply

cut the solder jumper, the tiny trace between the two

large gold pads marked Lite #18

gpio -g mode 18 pwm

gpio pwmc 1000

gpio -g pwm 18 100

gpio -g pwm 18 1023

gpio -g pwm 18 0

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g pmgpmyp. . ﬂ 7’ H =. a

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'

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"

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@ px®rasphenyp| . Q1 7 \ :- 5|

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* adafruit learning system

More Tips

Making it easier to click icons in X

If you want to double-click on icons to launch something in X you may find it annoying to get it to work right. In LXDE

you can simply set it up so that you only need to single click instead of double.

From LXDE launch the file manager (sorry these pix are grayscale and from the 2.8" TFT, still figuring out how to

screenshot the framebuffer!)

Then under the Edit menu, select Preferences

Then select Open files with single click and close the window (you'll need to drag it over to get to the X button

Right-click on a touchscreen

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Obviously if you have a touchscreen, it cannot tell what finger you are pressing with. This means that all 'clicks' are left

clicks. But if you want a right-click, you

can

do it.

Just add the following lines into your InputClass of /etc/X11/xorg.conf.d/99-calibration.conf after the calibration section

Option "EmulateThirdButton" "1"

Option "EmulateThirdButtonTimeout" "750"

Option "EmulateThirdButtonMoveThreshold" "30"

So for example your file will look like:

Section "InputClass"

Identifier "calibration"

MatchProduct "stmpe-ts"

Option "Calibration" "3800 120 200 3900"

Option "SwapAxes" "1"

Option "EmulateThirdButton" "1"

Option "EmulateThirdButtonTimeout" "750"

Option "EmulateThirdButtonMoveThreshold" "30"

EndSection

This makes a right mouse click emulated when holding down the stylus for 750 ms.

(Thx adamaddin! (https://adafru.it/fH3))

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* adafruit learning system

Gesture Input

With the PiTFT touchscreen and xstroke (https://adafru.it/dD0) 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 (https://adafru.it/dD1).

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

Now download, compile, and install xstroke by executing:

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:

Usage

To use xstroke I highly recommend using a plastic stylus instead of your finger. Also calibrate the touchscreen for X-

Windows (https://adafru.it/dD2) 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.

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

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

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/

Don't use a ballpoint pen or sharp metal stylus as it could scratch or damage the touchscreen!



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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

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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!

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* mlafrult Icammg system 51 cows , vurw '5) cows pm

PiTFT PyGame

Tips

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. (https://adafru.it/saw)

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 python-pip

Install Pygame: sudo apt-get install python-pygame

(this will take a while)

Ensure you are running SDL 1.2

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! (https://adafru.it/sax))

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Edit a new file with sudo nano installsdl.sh

and paste in the following text:

run

sudo chmod +x installsdl.sh

sudo ./installsdl.sh

#!/bin/bash

# enable wheezy package sources

echo "deb http://archive.raspbian.org/raspbian wheezy main

" > /etc/apt/sources.list.d/wheezy.list

# set stable as default package source (currently stretch)

echo "APT::Default-release \"stable\";

" > /etc/apt/apt.conf.d/10defaultRelease

# set the priority for libsdl from wheezy higher then the stretch package

echo "Package: libsdl1.2debian

Pin: release n=stretch

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

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g“ cows vum

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/PrzemoF/pitft_touchscreen (https://adafru.it/C2d)

here's another option

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https://github.com/nift4/pigame (https://adafru.it/CYv)

For examples:

https://github.com/nift4/Raspberry-Pi-Testing (https://adafru.it/CYy)

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* adafruit learning system



HELP! (FAQ)

My PiTFT used to work, now it doesn't!

If you messed with /boot/config.txt or /etc/rc.local you may have removed or disabled some of the elements

required for the PiTFT to work. Try re-running the Easy Installer script!

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I'm booting my Pi with the PiTFT and the HDMI output 'locks up' during boot!

It looks like the Pi is 'halting' or 'locking' up during boot but what is really happening is the console is switching from

the HDMI output to the PiTFT console output.

Check your PiTFT connections, particularly make sure you seated the PiTFT on the Pi properly, nothing is in the way,

and the TFT flex connector is seated properly.

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0| Aul'ul g)

My PiTFT works for a bit and then I get a black screen with a short line of white pixels in one corner

Sounds like you tried to configure your Pi to 'boot straight to X', that is, start up the graphics interface on boot. This

doesn't work by default because the Pi operating system is not expecting a PiTFT so it boots to the HDMI output.

See below for how to set up your Pi to boot to X on the PiTFT

To 'fix' this, you can either connect an HDMI monitor, then in a terminal window run sudo raspi-config and configure

the Pi to boot to the command line not X! If you do not have an HDMI monitor, you can also try a console cable

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I'm tring to run startx and I get FATAL: Module g2d_23 not found.

don't forget you have to remove the turbo file!

sudo mv /usr/share/X11/xorg.conf.d/99-fbturbo.conf ~

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How come OMX-Player and Minecraft and other programs don't appear on the PiTFT display?

Some programs are graphics-optimized, particularly the video playback tools and some other programs like

Minecraft. They write 'directly' to the HDMI output, and cannot write to the PiTFT so there is no way to directly make

them work. However, you

can

have the output go to HDMI and then mirror the HDMI onto the PiTFT with fbcp. Using

the Easy Installer, select Mirror HDMI

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Why doesn't the tactile button on GPIO #21 work?

On some older PiTFTs we had one of the buttons labeled #21 - that's the original RasPi name for that pin. If you're

using a V2 (chance is, you are!) that is now called #27.

All the PiTFT's we ship now have the button labeled #21 and #27

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I want better performance and faster updates!

You can change the SPI frequency (overclock the display) by editing /boot/config.txt and changing the dtoverlay

options line to:

dtoverlay=pitft28r,rotate=90,speed=62000000,fps=25

Or whatever you like for speed, rotation, and frames-per-second. BUT, here's the thing, the Pi only supports a

fixed

number

of SPI frequencies. So tweaking the number a little won't do anything. The kernel will round the number to

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

the closest value. You will always get frequencies that are 250MHz divided by an even number. Here's the only SPI

frequencies this kernel supports

15,625,000 (a.k.a 16000000 = 16 MHz)

17,857,142 (a.k.a. 18000000 = 18 MHz)

20,833,333 (a.k.a 21000000 = 21 MHz)

25,000,000 (= 25 MHz)

31,250,000 (a.k.a 32000000 = 32MHz)

41,666,666 (a.k.a 42000000 = 42MHz)

62,500,000 (a.k.a 62000000 = 62MHz)

So if you put in 48000000 for the speed, you won't actually get 48MHz, you'll actually only get about 42MHz

because it gets rounded down. We tested this display nicely with 32MHz and we suggest that. But you can put in

42MHz or even try 62MHz and it will update faster

You can tweak fps (frames per second) from 20 to 60 and frequency up to 62MHz for tradeoffs in performance and

speed. Reboot after each edit to make sure the settings are loaded properly. There's a trade off that if you ask for

higher FPS you're going to load the kernel more because it's trying to keep the display updated.

How can I take screenshots of the little screen?

We took the screenshots for this tutorial with fbgrab

wget http://fbgrab.monells.se/fbgrab-1.2.tar.gz

tar -zxvf fbgrab*gz

cd fbgrab/

make

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./fbgrab screenshot.png

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How do I automatically boot to X windows on the PiTFT?

Make sure your Pi boots to the graphical PIXEL desktop on the HDMI output monitor, then using the Easy Installer,

select Mirror HDMI

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My screen isn't working/works erratically/looks funny

Check to make syre that the flat flex cable is fully seated in the connetor and the 'ears' are pushed in to secure it.

See the picture for what it should look like:

pi Page 52 of 64

0| Aul'ul g)

pi Page 53 of 64

On my first run of startx I get a window saying "GDBus Error.org.Freedesktop Policy Kit1 Error: Failed

Cannot determine user of subject"

This happens on the Raspberry Pi the first time you run startx, no matter what display. You can just re-start X and it

wont appear again.

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Can I get a right-click from the touch-screen?

Yes! Please see this post:

https://forums.adafruit.com/viewtopic.php?f=47&t=77528&p=393280#p393322

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I'm having difficulties with the STMPE resistive touch screen controller

Here's a hack for the device tree overlay that can force different SPI modes, sometimes that helps!

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My PiTFT's rotation/calibration isn't working in X11

X11 (the graphical system) has changed how it gets touchscreen input, so if you rotate the display and the calibration

isn't being picked up:

Check /usr/share/X11/xorg.conf.d for a file called 10-evdev.conf

If you don't see that file

1. You need to sudo apt-get install xserver-xorg-input-evdev , and then...

2. If you do have a 40-libinput.conf in that same directory, you must remove it even if/once evdev is installed, since

it will override the 10-evdev.conf otherwise.

Thanks to cerebrate in the forums for the hint!

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0.... * adafruit learning system

Downloads

Files

The latest kernel fork that adds all the TFT, touchscreen, and other addons is here on github (https://adafru.it/aPa)

Datasheet for the controller chip (https://adafru.it/dQQ)

Datasheet for the 'raw' 3.5" TFT display (https://adafru.it/dR4)

PCB files on GitHub (https://adafru.it/rEC)

Fritzing object in the Adafruit Fritzing library (https://adafru.it/aP3)

Layout and Schematic for PiTFT Plus 3.5"

This is the newer PID 2441

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T—-I—FT sen (D 9 F1 Ham EH

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Layout and Schematic for original PiTFT 3.5"

This is the original PID #2097 version

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