raspberry pi waveshare 3.2'' Tft screen setup

I love using Archlinux, with fedora it's my favorite linux distro.
Since a long time i wanted to set a tft touch screen on my raspberry and run Kodi on it.
I bought  a cheep waveshare 3,2 ''  (exactly this one),  it's a resitive screen which  come s with a small  pencil and ... that all (actually it should come with a cd but ..not).

Installing Archlinux

I have a rapberry pi b+ and i follow the classique way to install Archlinux on the sdcard:


Find the disk using gparted
Umount the sdcard
umount /dev/sdX

Start fdisk to partition the SD card:

fdisk /dev/sdX

At the fdisk prompt, delete old partitions and create a new one:

1. Type o. This will clear out any partitions on the drive.
2. Type p to list partitions. There should be no partitions left.
3. Type n, then p for primary, 1 for the first partition on the drive, press ENTER to accept the default first sector, then type +100M for the last sector.
4. Type t, then c to set the first partition to type W95 FAT32 (LBA).
5. Type n, then p for primary, 2 for the second partition on the drive, and then press ENTER twice to accept the default first and last sector.
6. Write the partition table and exit by typing w.

Create and mount the FAT filesystem:

mkfs.vfat /dev/sdX1
mkdir boot
mount /dev/sdX1 boot

Create and mount the ext4 filesystem:

mkfs.ext4 /dev/sdX2
mkdir root
mount /dev/sdX2 root

Download and extract the root filesystem (as root, not via sudo):

wget http://archlinuxarm.org/os/ArchLinuxARM-rpi-latest.tar.gz
bsdtar -xpf ArchLinuxARM-rpi-latest.tar.gz -C root
sync

Move boot files to the first partition:

mv root/boot/* boot

Unmount the two partitions:

umount boot root

Updating

The next step is to connect to the raspberry to the network, login into then update packages to the latest release


Connect the raspberry to the network using the ethernet plug
Send power to the raspberry (5v usb)
From my machine i check the DHCP server on my ADSL router to know what is my Pi's IP
Then connect using SSH:
ssh alarm@192.168.XX.XX 
alarm@192.168.xx.xx's password: (a password will be asked juste enter alarm)
Welcome to Arch Linux ARM

     Website: http://archlinuxarm.org
       Forum: http://archlinuxarm.org/forum
         IRC: #archlinux-arm on irc.Freenode.net
[alarm@alarmpi ~]$ 

We are in !! 
Now we need to be root to do the update
su
Password: (the root password is ... root (no lol pleaz), note the prompt should change)
pacman -Syu 
:: Synchronizing package databases...
 core is up to date
 extra is up to date
 community is up to date
 alarm is up to date
 aur is up to date
:: Starting full system upgrade...
resolving dependencies...
looking for conflicting packages...

Packages (6) linux-raspberrypi-4.1.18-5  raspberrypi-firmware-20160304-1  raspberrypi-firmware-bootloader-20160304-1
             raspberrypi-firmware-bootloader-x-20160304-1  raspberrypi-firmware-examples-20160304-1
             raspberrypi-firmware-tools-20160304-1

Total Download Size:   58.00 MiB
Total Installed Size:  75.70 MiB
Net Upgrade Size:       0.00 MiB

:: Proceed with installation? [Y/n]  
choose Y
 
...
 it's up to date now

Installing the screen

we need to shutdown the raspberry 
as root:
halt -p

wait few second then remove the power plug of the pi and install the screen on it
Once done, put the power plug back into the Pi.
The TFT screen should light up.

Install some useful tools

As i like to be confortable when i work on unix like computer i always install a bunch of package (such a true editor ...)
as root:
pacman -S vim tmux git wget curl

Install the video driver

the framebuffer driver is available in the driver tree, so there is no need to download something or/and build.

ssh to the raspberry  and su root (as above)
edit the file /boot/config.txt and uncomment the following  line 
device_tree_param=spi=on

save it then reboot the raspberry, this is important to reboot or at the next step, the module we try to load will not be found
reboot


Once the pi has restart reconnect to it as root
now try the following line, the Pi tft screen should turn black:
modprobe fbtft_device custom name=fb_ili9340 speed=48000000 gpios=dc:22,reset:27 bgr=1 rotate=270
Edit etc/modules-load.d/raspberrypi.conf and add the following lines
spi-bcm2835
ifb_ili9340
fbtft_device
create a /etc/modprobe.d/fbftf.conf file with the following  
options fbtft_device custom name=fb_ili9340 speed=48000000 gpios=dc:22,reset:27 bgr=1 rotate=270

Install x packages

we need to install all the packages needed to go graphic.
Let's start with base X packages:

pacman -Syu xorg-server xorg-xinit xorg-server-utils

we continue with the driver in our case we use the frame buffer
pacman -S xf86-video-fb xf86-video-fbdev

then the input device
pacman -S xf86-input-evdev xf86-input-libinput




And finally i added some classic X Client

pacman -S xorg-twm xorg-xclock xterm

Configure X to work with fb

Modify or create file /etc/X11/xorg.conf.d/99-fbdev.conf as folow:

Section "Device"
  Identifier "myfb"
  Driver "fbdev"
  Option "fbdev" "/dev/fb1"
EndSection
 

Install and configure touch

Once again the driver is provide in the device tree.
First we add ads7845 to /etc/modules-load.d/raspberrypi.conf which should now look like this:

bcm2708-rng
snd-bcm2835
spi-bcm2835
fb_ili9340
fbtft_device
ads7845
  
the digitaliser needs some parameters which must be provide using the overlay mechanism.
It can be perform by modifying /boot/config.txt by adding :
dtoverlay=ads7846,speed=500000,penirq=17,swapxy=1

After a reboot here, you can check with a small test :
evtest
when you move the sylet on the screen it shout output stuff

to enable the configuration into X we have to add the folowing
Section "InputClass"    
Identifier      "calibration"    
MatchProduct    "ADS7846 Touchscreen"    
Option  "Calibration"  "3900 240 3900 240"    
EndSection
into /etc/X11/xorg.conf.d/99-calibration.conf

One more thing, if the mouse moves upset, add a /etc/X11/xorg.conf/99-inversion.conf as follow:
Section "InputClass"
       Identifier "axis inversion"
       MatchProduct "ADS7846 Touchscreen"
       # swap x/y axes on the device. i.e. rotate by 90 degrees
       Option "SwapAxes" "off"
       # Invert the respective axis.
       Option "InvertX" "on"
       Option "InvertY" "off"
EndSection

with different combinaison of swapAxes, InvertX , InvertY



usefull links:

https://github.com/raspberrypi/firmware/blob/master/boot/overlays/README
https://archlinuxarm.org/forum/viewtopic.php?f=64&t=9230
https://github.com/watterott/RPi-Display/blob/master/docu/FBTFT-Install.md
https://github.com/notro/rpi-firmware/issues/6
http://www.circuitbasics.com/raspberry-pi-touchscreen-calibration-screen-rotation/
https://archlinuxarm.org/forum/viewtopic.php?f=31&t=9208
https://github.com/phortx/Raspberry-Pi-Setup-Guide
https://github.com/notro/fbtft_tools/wiki/ads7846_device
https://fedoraproject.org/wiki/Input_device_configuration
https://github.com/notro/fbtft/issues/215
https://www.raspberrypi.org/forums/viewtopic.php?f=44&t=81150

Git basics (1st part)

GIT BASICS

Initialise a git repository 

$ git init .
this will create a git structure into the current directory.

Adding files

$ git add -A .
This (-A) will add all file including sub directories to the current branch (master) by default.

1st commit

$ git commit -m  "my first commit "
-m allow you to add a comment which will be visible  later.
The commit is performed locally so the remote repository will not be update (see push section below).

Create a branch

$ git checkout -b mybranch
this will create a branch "mybranch" and move git on it

 

Show all branches

$ git branch -v
this will show you all branches with commit logs. the * sign show which branch you are on.


Switch branch
$ git checkout mybranch
this will move you to mybranch


Add a remote repository
$git add remote orgin master http://....
this will add the branch master http://... as a remote repository (with the name orgin)


Push to a remote repository
$git push origin master
this will push the current branch to the remote repository origin branch master


Clone a remote repository
$git clone http://... target_folder
This is explicit enough

Hello

After years i decided to re-start blogging so this is my new blog. It will be mostly technical about devops/programming ..