wolverine5pl
Posts: 9
Joined: Fri Mar 18, 2016 5:20 pm

Re: Lcd Tft 3.5" Troubles

Fri Mar 18, 2016 9:53 pm

did you managed to get touchscreen to work?
https://github.com/swkim01/waveshare-dtoverlays was great. works for me.
but i cant get touch screen to work

nicolas le zombie
Posts: 1
Joined: Mon Apr 11, 2016 3:33 pm

Re: Lcd Tft 3.5" Troubles

Mon Apr 11, 2016 5:19 pm

I found a simple way to enhance the framerate on 3.5 tft waveshare screens at least, at the cost of time for research and tests!
I ended up with a line to change in config.txt:

> sudo nano /boot/config.txt
==> Find the line containing "dtoverlay=waveshare35a" and complete it as follow :
dtoverlay=waveshare35a:rotate=270,swapxy=1,speed=41000000,fps=50

I don't like to have the power cable downside cause I can't put the pi on its edge, so I flipped it with the rotate and swapxy options.
After numerous tests, I found that the best compromise between framerate and color depth was to set speed at 41000000 and fps at 50. For some reasons, if I change the speed to 42000000 or more, the color set fallback to 4K colors or so. Idem with fps.

>>> No more laggy display! :-)

On an other hand, I unfortunately keep being stuck with the backlight issue: impossible to dim it nor switch it off. I guess they omit to set an option or a gpio pin to deal with. A huge mistake according to me, who doesn't care about that? It makes the pi warm up and it consumes useless extra power when left on.

RobenLaan
Posts: 1
Joined: Thu Apr 14, 2016 2:18 pm

Re: Lcd Tft 3.5" Troubles

Thu Apr 14, 2016 2:25 pm

I've been working on exactly the same thing now, for 3 days. I've tried the drivers for the Waveshare 3.5 from the waveshare wiki. No luck.

Now I'm hoping this blogpost will be my solution, but I do not really get the steps I have to take. Please correct me if I'm wrong.
What I've done so far:

1. Install the Retropie image on my SD card.
2. Download the overlays from https://github.com/swkim01/waveshare-dtoverlays
3. Put the overlay for my Waveshare35a in the /boot/overlays directory
4. Go to /boot/config.txt and add these lines:

Code: Select all

dtparam=i2c_arm=on
hdmi_force_hotplug=1
hdmi_cvt=320 240 60 1 0 0 0
hdmi_group=2
hdmi_mode=87

dtoverlay=waveshare35a:rotate=90,speed=41000000,fps=50
5. Added the line in /boot/cmdline.txt to the end

Code: Select all

fbcon=map:1
Now, this is working for the boot sequence. But as soon as the Retropie interface starts, it goes back to HDMI and the LCD turns white. I probably forgot something somewhere... But what?

Thank you in advance!

samsgreen
Posts: 3
Joined: Thu Apr 28, 2016 12:21 pm

Re: Lcd Tft 3.5" Troubles

Thu Apr 28, 2016 12:22 pm

Hi, I have the exact same issue.

Did you find a way to get it working?

Any help would be greatly appreciated.

Thanks

DirkS
Posts: 9944
Joined: Tue Jun 19, 2012 9:46 pm
Location: Essex, UK

Re: Lcd Tft 3.5" Troubles

Thu Apr 28, 2016 1:26 pm

samsgreen wrote:Hi, I have the exact same issue.
Which issue? If it's about Retropie switching to HDMI then try using fbcp or raspi2fb.

samsgreen
Posts: 3
Joined: Thu Apr 28, 2016 12:21 pm

Re: Lcd Tft 3.5" Troubles

Fri Apr 29, 2016 9:43 am

I actually managed to get it working.

I had to ditch retropie, install raspbian and then install retropie.

I followed this guide: https://www.dropbox.com/s/y0u6i5a703b1c ... T.txt?dl=0

My only issue now is that after each reboot I have to ssh in and run:

[email protected]:~ $ sudo bash /home/pi/driver_workaround.sh
[email protected]:~ $ /home/pi/rpi-fbcp-master/build/fbcp &

before the screen will work. Anyway to get this to run on boot? I am a complete N00B. Thanks

DirkS
Posts: 9944
Joined: Tue Jun 19, 2012 9:46 pm
Location: Essex, UK

Re: Lcd Tft 3.5" Troubles

Fri Apr 29, 2016 10:01 am

samsgreen wrote:I actually managed to get it working.

I had to ditch retropie, install raspbian and then install retropie.

I followed this guide: https://www.dropbox.com/s/y0u6i5a703b1c ... T.txt?dl=0

My only issue now is that after each reboot I have to ssh in and run:

[email protected]:~ $ sudo bash /home/pi/driver_workaround.sh
[email protected]:~ $ /home/pi/rpi-fbcp-master/build/fbcp &

before the screen will work. Anyway to get this to run on boot? I am a complete N00B. Thanks
You could put those lines in /etc/rc.local (just before the line 'exit 0')
You can leave out the 'sudo', it's being run as root anyway.

samsgreen
Posts: 3
Joined: Thu Apr 28, 2016 12:21 pm

Re: Lcd Tft 3.5" Troubles

Fri Apr 29, 2016 10:06 am

That is amazing! Works great!

Just need to sort out the refresh rate, and im good! Thanks so much.

Wayno1337
Posts: 3
Joined: Thu May 19, 2016 1:19 pm

Re: Lcd Tft 3.5" Troubles

Sun May 29, 2016 5:35 am

dtoverlay=waveshare35a,speed=41000000,fps=50
fixes the scanlines/framerate issue, to at least something playable/usable..
However it still fu*ked up my colours so I went all the way down to: (which still works much better)
dtoverlay=waveshare35a,speed=27000000,fps=50
Then
dtoverlay=waveshare35a,speed=27000000,fps=60
worked, but I don't think that value makes any difference TBH, speed is the defining factor..
Please post your results and what worked for you, as I guess it comes down to the 'luck of the draw' with your LCD TFT/Circuitry as to what it can handle, wish I could use the higher setting lol.
On a related note, anyone care to link me to a more expensive 3.5" LCD that works flawlessly?
:]

tinylcd
Posts: 206
Joined: Sat Oct 26, 2013 4:07 am

Re: Lcd Tft 3.5" Troubles

Wed Jun 01, 2016 4:49 am

hello

you can have a look to below 3.5 inch tft lcds

http://www.neosecsolutions.com//index.p ... a9a58faf24

regards
tinylcd

tent
Posts: 1
Joined: Wed Aug 03, 2016 10:52 pm

Re: Lcd Tft 3.5" Troubles

Wed Aug 03, 2016 11:00 pm

maybe silly question but isn't there really no alternative to fbcp?
I mena there must be a config file somewhere to change the framebuffer that emulationstation uses by default (/dev/fb0) so that it will instead point to /dev/fb1 and so there will be no need to copy framebuffers nor change hdmi resolutions, right?
also hoping this would solve all issues with slughishness and colors..
any ideas or suggestions?

tent:wq

cqr
Posts: 4
Joined: Mon Feb 05, 2018 5:55 pm

Re: Lcd Tft 3.5" Troubles

Wed Feb 07, 2018 7:01 pm

nicolas le zombie wrote:
Mon Apr 11, 2016 5:19 pm
I found a simple way to enhance the framerate on 3.5 tft waveshare screens at least, at the cost of time for research and tests!
I ended up with a line to change in config.txt:

> sudo nano /boot/config.txt
==> Find the line containing "dtoverlay=waveshare35a" and complete it as follow :
dtoverlay=waveshare35a:rotate=270,swapxy=1,speed=41000000,fps=50

I don't like to have the power cable downside cause I can't put the pi on its edge, so I flipped it with the rotate and swapxy options.
After numerous tests, I found that the best compromise between framerate and color depth was to set speed at 41000000 and fps at 50. For some reasons, if I change the speed to 42000000 or more, the color set fallback to 4K colors or so. Idem with fps.

>>> No more laggy display! :-)

On an other hand, I unfortunately keep being stuck with the backlight issue: impossible to dim it nor switch it off. I guess they omit to set an option or a gpio pin to deal with. A huge mistake according to me, who doesn't care about that? It makes the pi warm up and it consumes useless extra power when left on.
My screen gets pixelated when i use this on my Waveshare screen. So if your screen gets pixelated, you can reduce speed between 40000000-41000000. If i try to reduce more than 40000000, it gets pixelated again. Yours might be different.

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