Hello, Everyone! Question: Has anyone tried to run lakka on a raspberry pi 3 with one of those gpio lcds? Does the screen work on that interface natively, is it needed/possible to install drivers, or does lakka strictly only support hdmi on Rpi3? Planning on building a battery powered portable unit, and was really impressed at how compact and slick the new rpi3/case/lcd combos can be!
Thank You all for your time and great help, and Happy Holidays!
I have, but the resolution was not that great. Touch Screen didn’t function as I recall. I decided to go another route. But Can spin up the RPi3 again to see full limitations.
We’re building this with Lakka
So yes, you can use a gpio screen. But I warn you, it requires technical knowledge. We even used Raspbian to prototype because it was easier.
That looks great! I’m ready for thinkering, as i just received the LCD tonight!!! The clear case, unfortunately, snapped in one corner, but oh well…i expected it a bit, as i was being as jentle as i could, but i saw those extremely thin acrylic walls lol Sooo…do i just install the driver from ssh like this: Download driver: http://www.waveshare.com/w/upload/3/3d/LCD-show-160811.tar.gz Add to /boot/config.txt <= unclear what I’m adding lol max_usb_current=1 hdmi_group=2 hdmi_mode=87 hdmi_cvt 800 480 60 6 0 0 0 Install: tar xzvf /boot/LCD-show-YYMMDD.tar.gz cd LCD-show/ ./LCD35-show
Yeah that will work on a Raspbian. It’s the LCD35-show which is the mysterious part you’ll have to add to lakka by another mean than the one they documented.
Well, then…the question is: how did YOU GUYS do it? 
If i understand correctly, the driver needs to be installed, then lakka needs to be told to use the LCD at boot from the config file. Is this the same file where you would set overclocks, or is it in retroarch.cfg?
Yes there is a part in config.txt, the same place where you do the overclock. This part will just set the video mode in your case.
Then there is another part, which is completely different depending on the screen. Most screens will use a kernel module (it’s like a driver).
In the case of gamegirl, we have a part in config.txt to set the video mode, rotate de screen, but we don’t use a kernel driver. We made a small C program that configure the screen in SPI mode using the GPIO. Which allowed us to have a very fast display (120Hz) while some other ways to do (called fbcp) can limit you to 25Hz.
So you’ll have to first do it on raspbian, then figure out how your screen works, what modes it supports, read the source of that LCD35-show and see what it does.
I’ve used the IMG directly from manufacturer, and can confirm screen works on Raspbian, but lcd performance is really poor. I presume that is what you were referring to as for the 120Hz? Screen looks great, but really slow response. Tried increasing GPU value in raspi-config, slightly faster, but not much.
I’m reimaging the SD now with the lakka backup, so i can keep thinkering…
Still reading…
This is what I get when I open LCD35-show with nano:
=======================================
if test "$var1" = "0";then
sudo mkdir /etc/X11/xorg.conf.d
echo "1" > ./boot/mark
fi
if test "$1" = "0" -o "$#" = "0";then
sudo cp -rf ./etc/X11/xorg.conf.d/99-calibration.conf-35
/etc/X11/xorg.conf.d/$
sudo cp ./boot/config-35.txt /boot/config.txt
echo "LCD configrue 0"
i=1
for lines in `cat ./boot/mark`
do
case ${i} in
1) var1=${lines};;
esac
i=`expr ${i} + 1`
done
==============================================
When I run it, I get a few loops of something similar to “…you don’t need sudo in openelec…”. So I said, fine, let me remove the instances of sudo from the commands…still nothing… I presume x11 and xorg are not used in lakka?
EDIT: This is the LCD35-show from the driver package alone:
==========================================
sudo mkdir /etc/X11/xorg.conf.d
sudo cp ./usr/tft35a-overlay.dtb /boot/overlays/
sudo cp ./usr/tft35a-overlay.dtb /boot/overlays/tft35a.dtbo
sudo cp -rf ./usr/99-calibration.conf-35 /etc/X11/xorg.conf.d/99-calibration.conf
sudo cp -rf ./usr/99-fbturbo.conf /usr/share/X11/xorg.conf.d/
sudo cp ./usr/cmdline.txt /boot/
sudo cp ./usr/inittab /etc/
sudo cp ./boot/config-35.txt /boot/config.txt
sudo reboot
==================================================#hdmi_safe=1
#disable_overscan=1
#overscan_left=16 #overscan_right=16 #overscan_top=16 #overscan_bottom=16
#framebuffer_width=1280 #framebuffer_height=720
hdmi_force_hotplug=1
#hdmi_group=1 #hdmi_mode=1
#hdmi_drive=2
#config_hdmi_boost=4
#sdtv_mode=2
#uncomment to overclock the arm. 700 MHz is the default. #arm_freq=800
One thing I tried was to image my SD with the gamegrrl image from the nightly on the vid above. Of course that didn’t boot on the Pi3, but I grabbed parts of the config file, specifically the lines past the “gamegrl specific” section, at the end…then added those lines to the config after I reimaged the sd with a working lakka backup. I tried as an exercise (in futility…lol), but of course it didn’t work…
Still reading and thinkering 
oh lord…horrible formatting, sorry, everyone 
No problem for the formatting
So what I see in this stuff is X11 configuration.
Try to see in raspbian if there is a special kernel module loaded for your screen, by typing
lsmod
Then also check if your screen supports SPI.
pi@raspberrypi:~ $ lsmod
Module Size Used by
bnep 10336 2
hci_uart 13533 1
btbcm 4196 1 hci_uart
bluetooth 317981 22 bnep,btbcm,hci_uart
brcmfmac 177635 0
brcmutil 5501 1 brcmfmac
cfg80211 407580 1 brcmfmac
joydev 9024 0
fb_ili9486 2750 2
ads7846 11138 0
fbtft 27484 1 fb_ili9486
hwmon 2684 1 ads7846
syscopyarea 2773 1 fbtft
sysfillrect 3299 1 fbtft
sysimgblt 1921 1 fbtft
rfkill 16036 4 cfg80211,bluetooth
fb_sys_fops 1157 1 fbtft
bcm2835_rng 1763 0
bcm2835_gpiomem 2860 0
i2c_bcm2708 4920 0
spi_bcm2835 7074 0
evdev 10278 8
w1_gpio 3401 0
wire 24703 1 w1_gpio
cn 4258 1 wire
uio_pdrv_genirq 2944 0
uio 7753 1 uio_pdrv_genirq
i2c_dev 5671 0
fuse 80694 3
ipv6 338660 34
==============================
would this be it > fbtft 27484 / 1 / fb_ili9486 ?
…and I believe the screen supports SPI…
I think that’s the module you’re using for the screen
In gamegirl, our screen is ILI9341
I think the doc is there http://www.displayfuture.com/Display/datasheet/controller/ILI9486L.pdf
The two screens look pretty similar. Maybe you can do like we did.
Any possibility the proper config could be put in a nightly? XD Kidding! So much info you threw my way, i’m just overwelmed…thank you very much for the help! Was the video showing how to config the screen on the gamegirl? I must have missed it…I’ll watch it again tomorrow…eyes burning… Buonanotte!
The video was not showing that part no. Just the result.
ugh…i need to make a bootable linux usb to read the partitions once flashed to sd…windows is useless in that aspect. All utilities i’ve tried either crashed or did nothing lol
Did you guys post a guide on the screen setup anywhere?