Sunday, February 10, 2013

Common Terminal Commands for your Raspberry Pi

Here is a quick list of the common terminal commands for the Raspberry Pi (RPi). If no one else uses this list, then I know that I will use it a lot. Here it goes:

  • sudo raspi-config       This command is used to access a frequently visited set up screen for your RPi.
  • sudo nano /boot/config.txt      This command is used to access and edit the boot configuration file of your RPi.
  • sudo reboot      This command is used to reboot your RPi from the terminal window.
  • /opt/vc/bin/vcgencmd measure_temp     This command is used to check your CPU temperature.
  • cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_cur_freq     This command is used to check your current CPU frequency.
  • vcgencmd get_config arm_freq      This command checks your current CPU frequency setting.
I will add more as I need and use them. I hope this helps.

    Saturday, February 9, 2013

    How to Fix Raspberry Pi HDMi to DVI Issue

    Hi All,

    So I have been having some fun with my Raspberry Pi (RPi) lately. I've been doing a lot of hands-on learning with it which is exactly what it was designed for. My first real problem with my RPi was to get it to work on a DVI-D computer monitor. The RPi works great with a straight HDMI connection to my LCD TV but I don't think the family wants me hogging the only LCD TV we have in the house with my mini computer. I also got it to work on old RCA input tube TV's. I even got a little 7" LCD TFT screen from eBay to work with it although the resolution is pretty bad especially on the tube TV. My first extra purchase was a DVI-D to HDMI 3 foot cable. This would have hopefully converted my DVI-D signal from my DVI-D monitor (monitor must be DVI-D) to the HDMI input of the RPi. I got it for $3.88 from eBay with free shipping from Utah. When it arrived I was very excited for about 5 minutes until I realized it didn't work. I actually went to Walmart that night to look for a cheap HDMI TV so I could work on my RPi without squinting at an old TV screen. Since I'm on a tight budget I did not buy one. I went home and started doing more research on the HDMI to DVI-D thing and it looked like it have been an issue for lots of people. Luckily it was a really simple solution that I was able to fix by editing the config.txt file. Here are the commands I used to do this. I had to do this while using the RCA video outputs in a terminal window.

    • sudo nano /boot/config.txt
    • add the following line or remove block (hashtag, #): hdmi_force_hotplug=1
    When you are done editing do the following:
    • press control & x
    • press y
    • press enter
     When you exiting the editor, restart your RPi using the following command
    • sudo reboot

    Once my RPi rebooted, I removed the RCA input and plugged in the HDMI cable and to my joy it booted up to my 20" LCD PC monitor.

    Friday, February 1, 2013

    My latest project, the $35 Raspberry Pi, HDMI Capable Computer

    I have an admission to make, for the last few years I have secretly becoming a computer geek! I got into building computers and messing around with Linux operating systems a while ago and lately I have been getting back into again. Most recently I came across this great piece of hardware, the Raspberry Pi (RPi), which is actually a computer with HDMI, Ethernet, USB, RCA, and Audio ports and more for only $35.00!! I was blown away at how small and affordable this board was so I had to have one. I just recently got mine in the mail along with a power supply and case for $55.00 shipped. Here are some pictures of it.

    My Raspberry Pi from MCM Electronics

    Raspberry Pi top view

    Raspberry Pi with case

    Raspberry Pi bottom view
    I also bought heat sinks to go on the processors and a power transistor. I got the heat sinks shipped to me from a US vendor for only $7.99 with free shipping. The heat sinks also came with the thermal adhesive on it for easy mounting. Here are some pictures of the heat sinks installed.

    Raspberry Pi with three aluminum heatsinks in case
    In order for the RPi to run you need to load an image file to an SD card which acts as its hard drive. There are many to choose from that have many purposes. I wanted to try it out as a small PC so I found a copy of Bodhi Enlightenment that was written specially for the RPi. It is a super bare bones version of Linux that works right out of the starting gate for me. I need more time to set things up and add more cool items to my $35 computer. Well more like $60 computer when you add up all the little things that go into it. Here is a picture:

    Bodhi Linux on my Raspberry Pi (RPi)