Wednesday, 18 June 2014 23:34
Removing Applications from Raspberry Pi
You might want to remove some applications to free up some space on SD card. Use the following syntax to uninstall a program
| sudo apt-get –purge remove APPNAME #replace APPNAME with the name of the app you want to remove |
An example to remove Scratch program
| sudo apt-get remove scratch |
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Tutorials
Tuesday, 10 June 2014 14:52
Raspberry Pi Digital Signage
Raspberry Pi (Model B) is a single-board computer that uses an ARM 11 (ARM1176JZF-S core) processor running at 700MHz (it can overclock up to 1GHz) with 512MB RAM.
This article shows you how to turn your Raspberry Pi into a cheap, browser based digital signage solution. It covers setting up a mini webserver on using the lighttpd+PHP web server and also how to start a web browser without a desktop environment.
I will use Midori as the web browser since it is a default browser that is found in Raspbian (a free operating system based on Debian optimized for the Raspberry Pi).
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Projects
Thursday, 22 May 2014 09:56
Raspberry Pi Schedule Turn OFF/ON Display
Edit the crontab file
|
sudo su - #switch to supuer user
crontab -e #edit crontab file
|
Put this line at the end of the file. This will turn off display at 5.30PM and turn on display at 8.30AM
|
30 17 * * * tvservice -o 30 8 * * * tvservice -p; fbset -depth 8; fbset -depth 16 |
Crontab syntax:
* * * * * command to be executed - - - - - | | | | | | | | | +----- day of week (0-6) (Sunday=0) | | | +------- month (1-12) | | +--------- day of month (1-31) | +----------- hour (0-23) +------------- minute (0-59)
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Tutorials
Wednesday, 21 May 2014 12:46
Raspberry Pi Schedule Reboot
Edit the crontab file
|
sudo su - #switch to supuer user
crontab -e #edit crontab file
|
Put this line at the end of the file. This will reboot the Raspberry Pi at 1.30PM every day.
| 30 13 * * * sudo reboot |
Crontab syntax:
* * * * * command to be executed - - - - - | | | | | | | | | +----- day of week (0-6) (Sunday=0) | | | +------- month (1-12) | | +--------- day of month (1-31) | +----------- hour (0-23) +------------- minute (0-59)
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Tutorials
Sunday, 18 May 2014 11:38
Configure the Raspberry Pi a Static IP Address
Example Configuration
- Raspberry IP: 192.168.0.123
- Router IP (Gateway): 192.168.0.254
- Subnet Mask: 255.255.255.0
List the network interface we currently have available:
| cat /etc/network/interfaces |
The output should look like this:
|
auto lo
iface lo inet loopback
iface eth0 inet dhcp allow-hotplug wlan0
iface wlan0 inet manual wpa-roam /etc/wpa_supplicant/wpa_supplicant.conf iface default inet dhcp |
The line iface eth0 inet dhcp shows that it is currently getting out IP address via DHCP. We need to change this line to iface eth0 inet static.
Edit /etc/network/interfaces
| sudo nano /etc/network/interfaces |
Change iface eth0 inet dhcp to iface eth0 inet static and add the following settings just below it:
|
address 192.168.0.123
netmask 255.255.255.0 network 192.168.0.0 broadcast 192.168.0.255 gateway 192.168.0.254 |
Here is an example:
|
auto lo iface lo inet loopback allow-hotplug wlan0 |
Finally, reboot the Raspberry Pi.
Fixing DNS problems
DNS is the service that converts the website URL, i.e. www.goggle.com into the IP address (173.194.126.36) that is needed for actual communication.
Check your DNS entrie
| cat /etc/resolv.conf |
Here is an example of the output
| nameserver 192.168.0.254 |
The nameserver should same as your gateway (your modem IP). If the nameserver and the gateway is different, you should modify the /etc/resolv.conf file and change the nameserver to your gateway IP.
| sudo nano /etc/resolv.conf |
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Tutorials
Monday, 05 May 2014 17:37
Changing the Screen Resolution for Raspberry Pi
View the current display configuration
| tvservice -s |
View the /boot/config.txt settings
| vcgencmd get_config int |
Get the list of what is supported by your monitor:
| tvservice -d dataFile #dump information to dataFile edidparser dataFile #load dataFile & display on screen |
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Tutorials
Monday, 05 May 2014 11:59
Raspberry Pi: Running Midori browser without a Desktop
Midori is a lightweight browser using the WebKit rendering engine and it is a default browser that is found in Raspbian. This is a quick quide to start the Midori browser from the command line without a desktop manager.
To start the Midori in full screen mode, use the following command:
xinit /usr/bin/midori -e Fullscreen -a http://domain/homepage.html
However it is not in full screen mode, it just fill up about quarter size of the screen. To fix this problem, Midori must run on a windows manager. Here is the solution:
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Blog
Sunday, 04 May 2014 20:43
Setup a Raspberry Pi PHP web server
Lighttpd is a lightweight web server, with all the essential functions of a web server, PHP is a server-side scripting language designed for web development but also used as a general-purpose programming language. This is a quide on how to install Lighttpd and PHP on a Raspberry Pi.
Prerequisite
- Raspberry pi running Raspbian OS
- SSH client such as PuTTy
- If you like to use GUI ( Graphical User Interface), WinSCP is preferred
- Netscanner software for IP address searching
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Blog
Monday, 11 February 2013 10:39
Resizing SD card partitions for Raspberry Pi
If you download the Raspbian image from Raspberry Pi official homepage and write it to the SD card, the SD card partition is fixed to 2GB, meaning that only 2GB is accessible no matter how big your SD card are. You must manually re-size the SD card partition in order to increase the available storage capacity.
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Blog
Sunday, 03 February 2013 18:35
Backing Up Raspberry Pi SD card
- Insert SD card to computer
- Launch Win32 Disk Imager
- Select Device (source) which you want to backup from
- Under Image File, give it a file name as shown in figure below
- Click Read button to start backing up
- As shown in figure below, the image file size is equivalent to the size of SD card since I had resized the partition of my SD card
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