Data Sheet

ManualsBrands4D Systems ManualsRaspberry Pi Accessories / HATs3.5" Primary Display for Raspberry Pi A+/B+/2

4D SYSTEMS 4DPi-35 Primary Display – Raspberry Pi Compatible

4DPi

-35

Primary Display

– Raspberry Pi

change to:

kernel=kernel_hat.img

Save the changes made to /boot/config.txt.

6) Shutdown the Raspberry Pi safely, and

remove the power.

7) Connect the 4DPi-35 to the Raspberry Pi, and

reapply power. The terminal should begin to

show on the 4DPi-35, and will be ready to use

once the Raspberry Pi has booted.

Calibrating the Touch Screen

Each 4DPi-35 which is shipped from the 4D

Systems factory is slightly different, in the sense

that each of the touch screens has a slightly

different calibration. In order to get the best from

your 4DPi-35, you will need to calibrate the display

so it is as accurate as possible.

To do this process, you will need an internet

connection to your raspberry Pi, so packages can

be installed as required.

There are 2 sorts of calibrations which can be

performed, depending on the requirements of the

User. The first process is for calibrating the touch

sensor for everything other than the LXDE GUI

itself. This is required for most applications. The

second is for calibrating the touch controller for

the LXDE GUI, ie when you run startx.

To calibrate the 4DPi-35, there are a few steps

required.

1) Install the "event test" and "touchscreen

library" packages to calibrate and debug the

touchscreen, using the following command:

sudo apt-get install evtest

tslib libts-bin

2) Calibrate the screen manually using the tslib

package, using the following command. You

should only need to do this once.

sudo TSLIB_FBDEVICE=/dev/fb1

TSLIB_TSDEVICE=/dev/input/event0

ts_calibrate

3) Follow the directions displayed on the screen.

It is recommended to use a stylus to achieve

the most accurate calibration. Do not use

anything metal or sharp which could damage

the touch screen.

You should see 5 touch targets, touch them on

by one. If you see less than 5 targets, then for

some reason you have triggered multiple

signals for a single touch, and you should

repeat the process from step 6 again.

4) To test if your calibration was satisfactory, you

can run the following command to draw on

the screen to show the accuracy of the touch.

sudo TSLIB_FBDEVICE=/dev/fb1

TSLIB_TSDEVICE=/dev/input/event0

ts_test

To calibrate the touch screen for the LDXE GUI, the

xinput_calibrator is required and the following

steps should be carried out. Make sure LDXE is not

running before you start, quite LDXE if it is and

return to the terminal prompt.

1) Delete the old calibration file, in preparation

for the new one. Do this BEFORE running

startx and the calibrator.

sudo rm /etc/X11/xorg.conf.d/99-

calibration.conf

2) This step is to be performed via a SSH session

to your Raspberry PI. If you wish to do this

directly with a keyboard on the Raspberry Pi

instead, skip to the next step. Enter the

following two commands:

FRAMEBUFFER=/dev/fb1 startx &

DISPLAY=:0.0 xinput_calibrator

3) This step is instead of step 2, if you are using a

keyboard connected to your Pi. Start the LXDE

GUI using the following command:

FRAMEBUFFER=/dev/fb1 startx

4) Execute the xinput_calibrator command

from the terminal after the LXDE GUI has

started.

5) Follow the directions on the screen. Once

complete you should get an output which

contains information such as this:

Section "InputClass"

Identifier "calibration"

MatchProduct "ads7846"

Option "Calibration" "119

3736 3850 174"

# Option "SwapAxes" "1"

EndSection

6) If the /etc/X11/xorg.conf.d directory does not

exist, it needs to be created manually.

mkdir /etc/X11/xorg.conf.d