So I wanted a super cheap but effective Kiosk. The Beaglebone Black (BBB) was a great choice with a 7″ screen from 4D Systems. It is a ARM Linux machine with 4GB of internal storage. I have a Rev C board that I got from Element 14.
For my project, I wanted a web server (sitting in front of a physical system I was controller) and a dedicated browser on the front panel.
Some Initial Steps
When I got the BBB Rev C, I plugged in the USB. No connection. Then I watched my router while I plugged in the network connection to see what IP address was served. Nothing. Then I found on the forums that the BBB may not have shipped with the intended OS installed. That was my case.
This guy’s site is pretty goodat describing the procedure even though he was using Ubuntu. You can get the latest debian image here. Install the OS and everything mentioned in the prior paragraph will magically be fixed.
Swapping In Lighttpd and PHP
The first step was to stop apache and bonescript so that we could install lighttpd and php.
Get a root shell on the BBB. This can be done using PuTTY on Windows or a Linux box. I used both because I am that sort of guy.
Start by disabling stuff that doesn’t matter.
systemctl disable bonescript.service systemctl disable bonescript.socket systemctl disable bonescript-autorun.service systemctl disable cloud9.socket systemctl disable mpd.service
You may want to keep cloud9 or mpd but the bonescript must go to install lighttpd.
The uninstall apache and udhcpd (which is provides a DHCP server).
update-rc.d apache2 disable systemctl disable apache2.service apt-get remove apache2 systemctl disable udhcpd update-rc.d udhcpd disable apt-get remove udhcpd
Then install lighttpd and php-cgi. I used sqlite too.
apt-get install lighttpd apt-get install php5-cgi apt-get install php5-sqlite lighty-enable-mod fastcgi lighty-enable-mod fastcgi-php
Modify your php and lighttpd configs as needed. (/etc/php5/cgi/php.ini and /etc/lighttpd/lighttpd.conf)
Put your pages in /var/www or wherever you prefer (as changed in lighttpd.conf). You can manually restart lighttpd but I just reboot because I am that kind of guy and the BBB boots in 10 seconds.
As mentioned before, our front panel was a 7″ display from 4D systems.
You can choose to remove X from running by disabling lightdm (associated server and sockets) using systemctl. I would rather keep the front panel and have a kiosk that is a web browser.
Side note: I tried to swap nodm for lightdm but ended up getting some error message that I don’t remember and got verify frustrated as X wouldn’t start except from command line. I suspect it had something to do with the order systemctl started certain services. I gave up because it wasn’t important to me to figure it out and reflashed the OS. I wanted to see of nodm and matchbox were better (i.e. smaller and faster) than lightdm and LXDE but oh well.
So, in this case, we will continue to use lightdm, have it auto logon to the debian account and start the kiosk.
This was really simple. There are two steps.
First, have chromium start when LXDE starts. Edit /etc/xdg/lxsession/LXDE/autostart. Comment out the lines beginning with @lxpanel and @pcmanfm. You don’t need the desktop panels and file manager. Add the following to the file: @chromium –disk-cache-dir=/dev/null –app=”http://localhost”. Of course, substitute your path if different. The disk-cache-dir set to /dev/null prohibits chromium from caching pages. This is critical if update your pages periodically.
If you have reviewed any chromium documentation, there is also a –kiosk flag. However, two very undesirable aspects arise. First, chromium balks about not having Google API keys installed. I don’t care but chromium is relentless. Second, if the browser is stopped hard, on the next startup, chromium asks if you want to restore your session. Again, I don’t care but chromium is relentless. Using the “app” flag guarantees these relentless messages do not appear. Also, you will not see any navigation bar, etc.
Second, the screen isn’t full and you get window decorations. Both need to go. Edit the /home/debian/.config/openbox/lxde-rc.xml file. Under the <applications> tag.
<application> <decor>no</decor> <fullscreen>yes</fullscreen> </application>
After the next reboot, you have a kiosk.
There were several things to be considered on the front panel.
First, the scroll bars are way too small for a finger. I didn’t get around to changing this. Scroll bars should be avoided. We will elaborate more.
Second, I have been in several companies now where they think that a browser on a PC will look the same as a browser on a 7″ display. Nope. Two problems. Real estate and the size of a finger versus the control of a mouse. Buttons have to be big and pages must minimize scrolling.
Third, in this day and age, we want to scroll by sliding our finger like a cell phone. Unfortunately, this is not the way this works in this case. Your finger is really a mouse and the screen is not a “real” touch device like a phone or tablet.
I want to play with Android for BBB but that will be a future article.