nemat
Posts: 6
Joined: Fri May 20, 2016 4:02 am

3.5" LCD touchscreen - problem with touch

Sat Dec 03, 2016 7:02 pm

Hi,

I've bought an 3.5" LCD touchscreen with a case from aliexpress and having trouble with touch events.
Guess this is a clone of waveshare, since waveshare script LCD35-show enables it and LCD screen works.
evtest shows that the button touch event works only once:

Testing ... (interrupt to exit)
Event: time 1480770594.951952, type 1 (EV_KEY), code 330 (BTN_TOUCH), value 1
Event: time 1480770594.951952, type 3 (EV_ABS), code 0 (ABS_X), value 363
Event: time 1480770594.951952, type 3 (EV_ABS), code 1 (ABS_Y), value 2512
Event: time 1480770594.951952, type 3 (EV_ABS), code 24 (ABS_PRESSURE), value 90
Event: time 1480770594.951952, -------------- EV_SYN ------------
Event: time 1480770594.962025, type 3 (EV_ABS), code 0 (ABS_X), value 350
Event: time 1480770594.962025, type 3 (EV_ABS), code 1 (ABS_Y), value 2516
Event: time 1480770594.962025, type 3 (EV_ABS), code 24 (ABS_PRESSURE), value 104

After the first EV_KEY/BTN_TOUCH there is no more such an event.

Tried many instructions that found through googles, but no way.

Could this be related to defective LCD screen or am I doing something wrong?

Hardware: RPI 3
OS: Up to date Raspian Jessie

Relevant configurations files:

/boot/cmdline.txt
dwc_otg.lpm_enable=0 console=tty1 console=ttyAMA0,115200 root=/dev/mmcblk0p2 rootfstype=ext4 elevator=deadline rootwait fbcon=map:10 fbcon=font:ProFont6x11 logo.nologo

/boot/config.txt
dtparam=i2c_arm=on
dtparam=spi=on
enable_uart=1
dtparam=audio=on
dtoverlay=waveshare35a
dtoverlay=ads7846,cs=1,penirq=17,penirq_pull=2,speed=1600000,keep_vref_on=1,swapxy=1,pmax=255,xohms=60,xmin=200,xmax=3900,ymin=200,ymax=3900

/etc/modules
i2c-dev

/etc/X11/xorg.conf.d/99-fbturbo.conf
Section "Device"
Identifier "Allwinner A10/A13 FBDEV"
Driver "fbturbo"
Option "fbdev" "/dev/fb1"

Option "SwapbuffersWait" "true"
EndSection

/usr/share/X11/xorg.conf.d/99-calibration.conf
Section "InputClass"
Identifier "calibration"
MatchProduct "ADS7846 Touchscreen"
Option "Calibration" "3932 300 294 3801"
Option "SwapAxes" "1"
EndSection

pawelPi85
Posts: 4
Joined: Tue Jan 17, 2017 10:15 am

Re: 3.5" LCD touchscreen - problem with touch

Mon Feb 27, 2017 2:28 pm

Hi,

I observed similar problem on my RPi (raspbian Jessie) and the same LCD 3.5 from AliExpress.
Does anybody solve this problem?
Could it be software or hardware problem?

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