Archive for November, 2015
I tested Ubuntu 14.04 LTS in VMware. I started with a clean install. I made sure sound was working in the VM, then updated everything using this command:
sudo apt-get update && sudo apt-get upgrade
I then checked Software Updater and found a few more packages that didn’t get updated, and updated them.
I then made a backup of the VM to have a good baseline. I then installed OpenJDK 7 and the icedtea-7-plugin, using the following command:
sudo apt-get install openjdk-7-jre icedtea-7-plugin
I did not have openjdk-6, icedtea 6, or Oracle Java installed. If you do have any of those installed, try removing them to prevent any conflicts.
You can test your Java sound output any trying any Java applet that produces sound, such as this SoundApplet demo. If you don’t hear sound from it, you have an issue. If you have more than 1 sound device, check the other sound device for the sound output. In my case I only had 1 device (through virtualization), but it worked fine.
I also tried AllStar and was able to hear audio from the node announcements just fine, albeit with occasional crackle, perhaps due to the limited resources of the VM. I tried transmitting but did not get a reply from the few nodes I tried.
If you have something to add, please feel free to comment below.
One of the uses I found for my Raspberry Pi was using it to display weather data. I retrieved the weather data from Weather Underground using their API, parsed it, and displayed it on my RPi’s small LCD. This gave me an always-on view of the weather, which was nifty, and it was done all in bash scripting with a few external programs to parse the data.
This script is very customizable and extensible. You could use it to do any number of weather-related tasks.
I reduced the font size on the LCD to Terminus 6×12 using the following command:
sudo dpkg-reconfigure console-setup
This helped make room for all the forecast data on the tiny LCD. If you are running this on a PC, it’s not necessary.
For the smoothest updates, I have found it ideal to run the script under ‘watch’, as so:
I tired doing a ‘while true; do… clear… done’ loop, but the refresh rate was too low and the updates were not smooth.
Here is the script:
UPDATE : This has moved to github, here.
Last updated: 11-21-2015
If you want your Raspberry Pi to share its files and folders over the network, you want to install and configure Samba.
Start off by installing the basic Samba requirements:
sudo apt-get install samba samba-common-bin
Edit the samba config file
sudo nano /etc/samba/smb.conf
edit the workgroup= line to match your network. workgroup=WORKGROUP is the default and usually fine. It needs to match what your Windows PCs are set to.
[pi] path=/home/pi browseable=Yes writeable=Yes only guest=no create mask=0777 directory mask=0777 public=no
Add the pi user to samba. Use the same password for the pi user:
sudo smbpasswd -a pi
It takes about 2 minutes for the changes to take effect, but after this you should have no problem exploring files over the network. Note that some may be owned by root and you may have an issue writing to them.
If you have trouble logging in under Windows (password errors), try using “raspberrypi\pi” (raspberrypi-backslash-pi) as your username (without the quotes)
sudo nano /boot/cmdline.txt
add the following to the end of the line:
I picked this inexpensive LCD up at MicroCenter for my Raspberry Pi, but getting it to work was a bit of a chore.
I wanted to install it onto a Raspberry Pi 2 which is already set up and running some software of mine. Therefore, I wanted to install it in as few steps as possible. Fortunately, WaveShare provides some drivers (but they don’t clearly document the setup process).
Here’s now to set it up:
Do the normal update/upgrade procedure:
sudo apt-get update && sudo apt-get upgrade
Download the correct “LCD-show-*” driver for your version of Raspbian Jessie from the Drivers section of the product page on WaveShare, and transfer it to your Pi, or use the following example commands from your Pi to download it directly:
wget http://www.waveshare.com/w/upload/9/9d/LCD-show-151020.tar.gz tar xvzf LCD-show-151020.tar.gz cd LCD-show/
and run this command to set up the 3.2″ screen. :
Note: You may need to have the SPI interface already turned up via raspi-config before this will work.
Important note: The LCD32-show and LCD-hdmi scripts will overwrite several system files. If you have customized them, or have concerns, you are strongly advised to read through the scripts before running, and consider merging the changes in manually. Here is the list of touched files:
After a few seconds, you Pi will reboot, and the screen should be active. You can refer back to the WaveShare page to see documentation on how to switch to HDMI and back to the LCD.
Follow these steps to download and install xinput_calibrator to calibrate the touchscreen. I noticed that on my panel, the touchscreen does not respond well to input; I suspect I have a defective panel.
sudo apt-get install libx11-dev libxext-dev libxi-dev x11proto-input-dev wget http://github.com/downloads/tias/xinput_calibrator/xinput_calibrator-0.7.5.tar.gz ./configure make sudo make install
Now, following the directions from WaveShare, you can run this command to calibrate the touchscreen:
Refer to WaveShare’s page on how to edit 99-calibration.conf to save the calibration data so it persists over reboots.
Comments are welcome.
The Raspberry Pi has two LEDs on the front: One hardwired as a power indicator, and the other is (by default) an SD card activity indicator. This second LED can be changed via software to anything (even a GPIO), but for this, I’m going to show you how to set it as a heartbeat indicator.
sudo su modprobe ledtrig_heartbeat echo heartbeat > /sys/class/leds/led0/trigger
The Pi’s led should now start blinking as a heartbeat indicator. If you want to restore the default behavior, you can do so:
echo mmc0 > /sys/class/leds/led0/trigger
That’s all there is to it.